November 2022 - Linux-stable-mirror

stable-rc/linux-4.9.y baseline: 78 runs, 9 regressions (v4.9.332-20-g6ba04d5b05d0)

by kernelci.org bot

stable-rc/linux-4.9.y baseline: 78 runs, 9 regressions (v4.9.332-20-g6ba04d5b05d0) Regressions Summary ------------------- platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv2 | arm64 | lab-baylibre | gcc-10 | defconfig | 1 qemu_arm64-virt-gicv2 | arm64 | lab-baylibre | gcc-10 | defconfig+arm64-chromebook | 1 qemu_arm64-virt-gicv2-uefi | arm64 | lab-baylibre | gcc-10 | defconfig | 1 qemu_arm64-virt-gicv2-uefi | arm64 | lab-baylibre | gcc-10 | defconfig+arm64-chromebook | 1 qemu_arm64-virt-gicv3 | arm64 | lab-baylibre | gcc-10 | defconfig | 1 qemu_arm64-virt-gicv3 | arm64 | lab-baylibre | gcc-10 | defconfig+arm64-chromebook | 1 qemu_arm64-virt-gicv3 | arm64 | lab-collabora | gcc-10 | defconfig | 1 qemu_arm64-virt-gicv3-uefi | arm64 | lab-baylibre | gcc-10 | defconfig | 1 qemu_arm64-virt-gicv3-uefi | arm64 | lab-baylibre | gcc-10 | defconfig+arm64-chromebook | 1 Details: https://kernelci.org/test/job/stable-rc/branch/linux-4.9.y/kernel/v4.9.332-… Test: baseline Tree: stable-rc Branch: linux-4.9.y Describe: v4.9.332-20-g6ba04d5b05d0 URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git SHA: 6ba04d5b05d0fa40a92d5232d4e79af5aff5b447 Test Regressions ---------------- platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv2 | arm64 | lab-baylibre | gcc-10 | defconfig | 1 Details: https://kernelci.org/test/plan/id/6368c71a067df5b459e7db54 Results: 0 PASS, 1 FAIL, 0 SKIP Full config: defconfig Compiler: gcc-10 (aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110) Plain log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… HTML log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/buildroot-baseline/2022… * baseline.login: https://kernelci.org/test/case/id/6368c71a067df5b459e7db55 failing since 181 days (last pass: v4.9.312-44-g77a374c13dc5, first fail: v4.9.312-60-g806e59090c6c) platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv2 | arm64 | lab-baylibre | gcc-10 | defconfig+arm64-chromebook | 1 Details: https://kernelci.org/test/plan/id/6368c8bfa3c4157dd7e7db6b Results: 0 PASS, 1 FAIL, 0 SKIP Full config: defconfig+arm64-chromebook Compiler: gcc-10 (aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110) Plain log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… HTML log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/buildroot-baseline/2022… * baseline.login: https://kernelci.org/test/case/id/6368c8bfa3c4157dd7e7db6c failing since 181 days (last pass: v4.9.312-36-gbfd3fd9fa677, first fail: v4.9.312-60-g806e59090c6c) platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv2-uefi | arm64 | lab-baylibre | gcc-10 | defconfig | 1 Details: https://kernelci.org/test/plan/id/6368c71b3a35908d91e7db5e Results: 0 PASS, 1 FAIL, 0 SKIP Full config: defconfig Compiler: gcc-10 (aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110) Plain log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… HTML log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/buildroot-baseline/2022… * baseline.login: https://kernelci.org/test/case/id/6368c71b3a35908d91e7db5f failing since 181 days (last pass: v4.9.312-44-g77a374c13dc5, first fail: v4.9.312-60-g806e59090c6c) platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv2-uefi | arm64 | lab-baylibre | gcc-10 | defconfig+arm64-chromebook | 1 Details: https://kernelci.org/test/plan/id/6368c8c1c412bac80be7db6b Results: 0 PASS, 1 FAIL, 0 SKIP Full config: defconfig+arm64-chromebook Compiler: gcc-10 (aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110) Plain log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… HTML log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/buildroot-baseline/2022… * baseline.login: https://kernelci.org/test/case/id/6368c8c1c412bac80be7db6c failing since 181 days (last pass: v4.9.312-36-gbfd3fd9fa677, first fail: v4.9.312-60-g806e59090c6c) platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv3 | arm64 | lab-baylibre | gcc-10 | defconfig | 1 Details: https://kernelci.org/test/plan/id/6368c71952d81de29de7db4f Results: 0 PASS, 1 FAIL, 0 SKIP Full config: defconfig Compiler: gcc-10 (aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110) Plain log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… HTML log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/buildroot-baseline/2022… * baseline.login: https://kernelci.org/test/case/id/6368c71952d81de29de7db50 failing since 65 days (last pass: v4.9.302-27-ge4a64678c410, first fail: v4.9.326-32-g24fc65df6e8a8) platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv3 | arm64 | lab-baylibre | gcc-10 | defconfig+arm64-chromebook | 1 Details: https://kernelci.org/test/plan/id/6368c8bda3c4157dd7e7db68 Results: 0 PASS, 1 FAIL, 0 SKIP Full config: defconfig+arm64-chromebook Compiler: gcc-10 (aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110) Plain log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… HTML log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/buildroot-baseline/2022… * baseline.login: https://kernelci.org/test/case/id/6368c8bda3c4157dd7e7db69 failing since 181 days (last pass: v4.9.312-36-gbfd3fd9fa677, first fail: v4.9.312-60-g806e59090c6c) platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv3 | arm64 | lab-collabora | gcc-10 | defconfig | 1 Details: https://kernelci.org/test/plan/id/6368c708f77ec67343e7db6b Results: 0 PASS, 1 FAIL, 0 SKIP Full config: defconfig Compiler: gcc-10 (aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110) Plain log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… HTML log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/buildroot-baseline/2022… * baseline.login: https://kernelci.org/test/case/id/6368c708f77ec67343e7db6c failing since 65 days (last pass: v4.9.302-27-ge4a64678c410, first fail: v4.9.326-32-g24fc65df6e8a8) platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv3-uefi | arm64 | lab-baylibre | gcc-10 | defconfig | 1 Details: https://kernelci.org/test/plan/id/6368c7183a35908d91e7db56 Results: 0 PASS, 1 FAIL, 0 SKIP Full config: defconfig Compiler: gcc-10 (aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110) Plain log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… HTML log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/buildroot-baseline/2022… * baseline.login: https://kernelci.org/test/case/id/6368c7183a35908d91e7db57 failing since 181 days (last pass: v4.9.312-44-g77a374c13dc5, first fail: v4.9.312-60-g806e59090c6c) platform | arch | lab | compiler | defconfig | regressions ---------------------------+-------+---------------+----------+----------------------------+------------ qemu_arm64-virt-gicv3-uefi | arm64 | lab-baylibre | gcc-10 | defconfig+arm64-chromebook | 1 Details: https://kernelci.org/test/plan/id/6368c8c3a3c4157dd7e7db6e Results: 0 PASS, 1 FAIL, 0 SKIP Full config: defconfig+arm64-chromebook Compiler: gcc-10 (aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110) Plain log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… HTML log: https://storage.kernelci.org//stable-rc/linux-4.9.y/v4.9.332-20-g6ba04d5b05… Rootfs: http://storage.kernelci.org/images/rootfs/buildroot/buildroot-baseline/2022… * baseline.login: https://kernelci.org/test/case/id/6368c8c3a3c4157dd7e7db6f failing since 181 days (last pass: v4.9.312-36-gbfd3fd9fa677, first fail: v4.9.312-60-g806e59090c6c)

2 years, 1 month

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FAILED: patch "[PATCH] ftrace: Fix use-after-free for dynamic ftrace_ops" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 0e792b89e680 ("ftrace: Fix use-after-free for dynamic ftrace_ops") fc0ea795f53c ("ftrace: Add symbols for ftrace trampolines") b3a88803ac5b ("ftrace: Kill FTRACE_OPS_FL_PER_CPU") 6171a0310a06 ("ftrace/kallsyms: Have /proc/kallsyms show saved mod init functions") aba4b5c22cba ("ftrace: Save module init functions kallsyms symbols for tracing") 3e234289f86b ("ftrace: Allow module init functions to be traced") 6cafbe159416 ("ftrace: Add a ftrace_free_mem() function for modules to use") edb096e00724 ("ftrace: Fix memleak when unregistering dynamic ops when tracing disabled") 8c08f0d5c6fb ("ftrace: Have cached module filters be an active filter") d7fbf8df7ca0 ("ftrace: Implement cached modules tracing on module load") 673feb9d76ab ("ftrace: Add :mod: caching infrastructure to trace_array") d0ba52f1d764 ("ftrace: Add missing comment for FTRACE_OPS_FL_RCU") 04ec7bb642b7 ("tracing: Have the trace_array hold the list of registered func probes") eee8ded131f1 ("ftrace: Have the function probes call their own function") 1ec3a81a0cf4 ("ftrace: Have each function probe use its own ftrace_ops") d3d532d798c5 ("ftrace: Have unregister_ftrace_function_probe_func() return a value") 1a48df0041c2 ("ftrace: Remove data field from ftrace_func_probe structure") 02b77e2afb49 ("ftrace: Remove printing of data in showing of a function probe") 78f78e07d51e ("ftrace: Remove unused unregister_ftrace_function_probe_all() function") 0fe7e7e3f839 ("ftrace: Remove unused unregister_ftrace_function_probe() function") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0e792b89e6800cd9cb4757a76a96f7ef3e8b6294 Mon Sep 17 00:00:00 2001 From: Li Huafei <lihuafei1(a)huawei.com> Date: Thu, 3 Nov 2022 11:10:10 +0800 Subject: [PATCH] ftrace: Fix use-after-free for dynamic ftrace_ops KASAN reported a use-after-free with ftrace ops [1]. It was found from vmcore that perf had registered two ops with the same content successively, both dynamic. After unregistering the second ops, a use-after-free occurred. In ftrace_shutdown(), when the second ops is unregistered, the FTRACE_UPDATE_CALLS command is not set because there is another enabled ops with the same content. Also, both ops are dynamic and the ftrace callback function is ftrace_ops_list_func, so the FTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value of 'command' will be 0 and ftrace_shutdown() will skip the rcu synchronization. However, ftrace may be activated. When the ops is released, another CPU may be accessing the ops. Add the missing synchronization to fix this problem. [1] BUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] BUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 Read of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468 CPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132 show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b4/0x248 lib/dump_stack.c:118 print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387 __kasan_report mm/kasan/report.c:547 [inline] kasan_report+0x118/0x210 mm/kasan/report.c:564 check_memory_region_inline mm/kasan/generic.c:187 [inline] __asan_load8+0x98/0xc0 mm/kasan/generic.c:253 __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 ftrace_graph_call+0x0/0x4 __might_sleep+0x8/0x100 include/linux/perf_event.h:1170 __might_fault mm/memory.c:5183 [inline] __might_fault+0x58/0x70 mm/memory.c:5171 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139 getname_flags+0xb0/0x31c fs/namei.c:149 getname+0x2c/0x40 fs/namei.c:209 [...] Allocated by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:479 [inline] __kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493 kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:675 [inline] perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 __arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723 [...] Freed by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track+0x24/0x34 mm/kasan/common.c:56 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358 __kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437 __kasan_slab_free mm/kasan/common.c:445 [inline] kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446 slab_free_hook mm/slub.c:1569 [inline] slab_free_freelist_hook mm/slub.c:1608 [inline] slab_free mm/slub.c:3179 [inline] kfree+0x12c/0xc10 mm/slub.c:4176 perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 [...] Link: https://lore.kernel.org/linux-trace-kernel/20221103031010.166498-1-lihuafei… Fixes: edb096e00724f ("ftrace: Fix memleak when unregistering dynamic ops when tracing disabled") Cc: stable(a)vger.kernel.org Suggested-by: Steven Rostedt <rostedt(a)goodmis.org> Signed-off-by: Li Huafei <lihuafei1(a)huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index fbf2543111c0..7dc023641bf1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3028,18 +3028,8 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) command |= FTRACE_UPDATE_TRACE_FUNC; } - if (!command || !ftrace_enabled) { - /* - * If these are dynamic or per_cpu ops, they still - * need their data freed. Since, function tracing is - * not currently active, we can just free them - * without synchronizing all CPUs. - */ - if (ops->flags & FTRACE_OPS_FL_DYNAMIC) - goto free_ops; - - return 0; - } + if (!command || !ftrace_enabled) + goto out; /* * If the ops uses a trampoline, then it needs to be @@ -3076,6 +3066,7 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) removed_ops = NULL; ops->flags &= ~FTRACE_OPS_FL_REMOVING; +out: /* * Dynamic ops may be freed, we must make sure that all * callers are done before leaving this function. @@ -3103,7 +3094,6 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) if (IS_ENABLED(CONFIG_PREEMPTION)) synchronize_rcu_tasks(); - free_ops: ftrace_trampoline_free(ops); }

2 years, 1 month

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FAILED: patch "[PATCH] ftrace: Fix use-after-free for dynamic ftrace_ops" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 0e792b89e680 ("ftrace: Fix use-after-free for dynamic ftrace_ops") fc0ea795f53c ("ftrace: Add symbols for ftrace trampolines") b3a88803ac5b ("ftrace: Kill FTRACE_OPS_FL_PER_CPU") 6171a0310a06 ("ftrace/kallsyms: Have /proc/kallsyms show saved mod init functions") aba4b5c22cba ("ftrace: Save module init functions kallsyms symbols for tracing") 3e234289f86b ("ftrace: Allow module init functions to be traced") 6cafbe159416 ("ftrace: Add a ftrace_free_mem() function for modules to use") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0e792b89e6800cd9cb4757a76a96f7ef3e8b6294 Mon Sep 17 00:00:00 2001 From: Li Huafei <lihuafei1(a)huawei.com> Date: Thu, 3 Nov 2022 11:10:10 +0800 Subject: [PATCH] ftrace: Fix use-after-free for dynamic ftrace_ops KASAN reported a use-after-free with ftrace ops [1]. It was found from vmcore that perf had registered two ops with the same content successively, both dynamic. After unregistering the second ops, a use-after-free occurred. In ftrace_shutdown(), when the second ops is unregistered, the FTRACE_UPDATE_CALLS command is not set because there is another enabled ops with the same content. Also, both ops are dynamic and the ftrace callback function is ftrace_ops_list_func, so the FTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value of 'command' will be 0 and ftrace_shutdown() will skip the rcu synchronization. However, ftrace may be activated. When the ops is released, another CPU may be accessing the ops. Add the missing synchronization to fix this problem. [1] BUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] BUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 Read of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468 CPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132 show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b4/0x248 lib/dump_stack.c:118 print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387 __kasan_report mm/kasan/report.c:547 [inline] kasan_report+0x118/0x210 mm/kasan/report.c:564 check_memory_region_inline mm/kasan/generic.c:187 [inline] __asan_load8+0x98/0xc0 mm/kasan/generic.c:253 __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 ftrace_graph_call+0x0/0x4 __might_sleep+0x8/0x100 include/linux/perf_event.h:1170 __might_fault mm/memory.c:5183 [inline] __might_fault+0x58/0x70 mm/memory.c:5171 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139 getname_flags+0xb0/0x31c fs/namei.c:149 getname+0x2c/0x40 fs/namei.c:209 [...] Allocated by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:479 [inline] __kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493 kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:675 [inline] perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 __arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723 [...] Freed by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track+0x24/0x34 mm/kasan/common.c:56 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358 __kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437 __kasan_slab_free mm/kasan/common.c:445 [inline] kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446 slab_free_hook mm/slub.c:1569 [inline] slab_free_freelist_hook mm/slub.c:1608 [inline] slab_free mm/slub.c:3179 [inline] kfree+0x12c/0xc10 mm/slub.c:4176 perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 [...] Link: https://lore.kernel.org/linux-trace-kernel/20221103031010.166498-1-lihuafei… Fixes: edb096e00724f ("ftrace: Fix memleak when unregistering dynamic ops when tracing disabled") Cc: stable(a)vger.kernel.org Suggested-by: Steven Rostedt <rostedt(a)goodmis.org> Signed-off-by: Li Huafei <lihuafei1(a)huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index fbf2543111c0..7dc023641bf1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3028,18 +3028,8 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) command |= FTRACE_UPDATE_TRACE_FUNC; } - if (!command || !ftrace_enabled) { - /* - * If these are dynamic or per_cpu ops, they still - * need their data freed. Since, function tracing is - * not currently active, we can just free them - * without synchronizing all CPUs. - */ - if (ops->flags & FTRACE_OPS_FL_DYNAMIC) - goto free_ops; - - return 0; - } + if (!command || !ftrace_enabled) + goto out; /* * If the ops uses a trampoline, then it needs to be @@ -3076,6 +3066,7 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) removed_ops = NULL; ops->flags &= ~FTRACE_OPS_FL_REMOVING; +out: /* * Dynamic ops may be freed, we must make sure that all * callers are done before leaving this function. @@ -3103,7 +3094,6 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) if (IS_ENABLED(CONFIG_PREEMPTION)) synchronize_rcu_tasks(); - free_ops: ftrace_trampoline_free(ops); }

2 years, 1 month

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FAILED: patch "[PATCH] ftrace: Fix use-after-free for dynamic ftrace_ops" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 0e792b89e680 ("ftrace: Fix use-after-free for dynamic ftrace_ops") fc0ea795f53c ("ftrace: Add symbols for ftrace trampolines") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0e792b89e6800cd9cb4757a76a96f7ef3e8b6294 Mon Sep 17 00:00:00 2001 From: Li Huafei <lihuafei1(a)huawei.com> Date: Thu, 3 Nov 2022 11:10:10 +0800 Subject: [PATCH] ftrace: Fix use-after-free for dynamic ftrace_ops KASAN reported a use-after-free with ftrace ops [1]. It was found from vmcore that perf had registered two ops with the same content successively, both dynamic. After unregistering the second ops, a use-after-free occurred. In ftrace_shutdown(), when the second ops is unregistered, the FTRACE_UPDATE_CALLS command is not set because there is another enabled ops with the same content. Also, both ops are dynamic and the ftrace callback function is ftrace_ops_list_func, so the FTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value of 'command' will be 0 and ftrace_shutdown() will skip the rcu synchronization. However, ftrace may be activated. When the ops is released, another CPU may be accessing the ops. Add the missing synchronization to fix this problem. [1] BUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] BUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 Read of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468 CPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132 show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b4/0x248 lib/dump_stack.c:118 print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387 __kasan_report mm/kasan/report.c:547 [inline] kasan_report+0x118/0x210 mm/kasan/report.c:564 check_memory_region_inline mm/kasan/generic.c:187 [inline] __asan_load8+0x98/0xc0 mm/kasan/generic.c:253 __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 ftrace_graph_call+0x0/0x4 __might_sleep+0x8/0x100 include/linux/perf_event.h:1170 __might_fault mm/memory.c:5183 [inline] __might_fault+0x58/0x70 mm/memory.c:5171 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139 getname_flags+0xb0/0x31c fs/namei.c:149 getname+0x2c/0x40 fs/namei.c:209 [...] Allocated by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:479 [inline] __kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493 kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:675 [inline] perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 __arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723 [...] Freed by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track+0x24/0x34 mm/kasan/common.c:56 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358 __kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437 __kasan_slab_free mm/kasan/common.c:445 [inline] kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446 slab_free_hook mm/slub.c:1569 [inline] slab_free_freelist_hook mm/slub.c:1608 [inline] slab_free mm/slub.c:3179 [inline] kfree+0x12c/0xc10 mm/slub.c:4176 perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 [...] Link: https://lore.kernel.org/linux-trace-kernel/20221103031010.166498-1-lihuafei… Fixes: edb096e00724f ("ftrace: Fix memleak when unregistering dynamic ops when tracing disabled") Cc: stable(a)vger.kernel.org Suggested-by: Steven Rostedt <rostedt(a)goodmis.org> Signed-off-by: Li Huafei <lihuafei1(a)huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index fbf2543111c0..7dc023641bf1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3028,18 +3028,8 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) command |= FTRACE_UPDATE_TRACE_FUNC; } - if (!command || !ftrace_enabled) { - /* - * If these are dynamic or per_cpu ops, they still - * need their data freed. Since, function tracing is - * not currently active, we can just free them - * without synchronizing all CPUs. - */ - if (ops->flags & FTRACE_OPS_FL_DYNAMIC) - goto free_ops; - - return 0; - } + if (!command || !ftrace_enabled) + goto out; /* * If the ops uses a trampoline, then it needs to be @@ -3076,6 +3066,7 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) removed_ops = NULL; ops->flags &= ~FTRACE_OPS_FL_REMOVING; +out: /* * Dynamic ops may be freed, we must make sure that all * callers are done before leaving this function. @@ -3103,7 +3094,6 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) if (IS_ENABLED(CONFIG_PREEMPTION)) synchronize_rcu_tasks(); - free_ops: ftrace_trampoline_free(ops); }

2 years, 1 month

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FAILED: patch "[PATCH] ftrace: Fix use-after-free for dynamic ftrace_ops" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 0e792b89e680 ("ftrace: Fix use-after-free for dynamic ftrace_ops") fc0ea795f53c ("ftrace: Add symbols for ftrace trampolines") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0e792b89e6800cd9cb4757a76a96f7ef3e8b6294 Mon Sep 17 00:00:00 2001 From: Li Huafei <lihuafei1(a)huawei.com> Date: Thu, 3 Nov 2022 11:10:10 +0800 Subject: [PATCH] ftrace: Fix use-after-free for dynamic ftrace_ops KASAN reported a use-after-free with ftrace ops [1]. It was found from vmcore that perf had registered two ops with the same content successively, both dynamic. After unregistering the second ops, a use-after-free occurred. In ftrace_shutdown(), when the second ops is unregistered, the FTRACE_UPDATE_CALLS command is not set because there is another enabled ops with the same content. Also, both ops are dynamic and the ftrace callback function is ftrace_ops_list_func, so the FTRACE_UPDATE_TRACE_FUNC command will not be set. Eventually the value of 'command' will be 0 and ftrace_shutdown() will skip the rcu synchronization. However, ftrace may be activated. When the ops is released, another CPU may be accessing the ops. Add the missing synchronization to fix this problem. [1] BUG: KASAN: use-after-free in __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] BUG: KASAN: use-after-free in ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 Read of size 8 at addr ffff56551965bbc8 by task syz-executor.2/14468 CPU: 1 PID: 14468 Comm: syz-executor.2 Not tainted 5.10.0 #7 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x40c arch/arm64/kernel/stacktrace.c:132 show_stack+0x30/0x40 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1b4/0x248 lib/dump_stack.c:118 print_address_description.constprop.0+0x28/0x48c mm/kasan/report.c:387 __kasan_report mm/kasan/report.c:547 [inline] kasan_report+0x118/0x210 mm/kasan/report.c:564 check_memory_region_inline mm/kasan/generic.c:187 [inline] __asan_load8+0x98/0xc0 mm/kasan/generic.c:253 __ftrace_ops_list_func kernel/trace/ftrace.c:7020 [inline] ftrace_ops_list_func+0x2b0/0x31c kernel/trace/ftrace.c:7049 ftrace_graph_call+0x0/0x4 __might_sleep+0x8/0x100 include/linux/perf_event.h:1170 __might_fault mm/memory.c:5183 [inline] __might_fault+0x58/0x70 mm/memory.c:5171 do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] strncpy_from_user+0x1f4/0x4b0 lib/strncpy_from_user.c:139 getname_flags+0xb0/0x31c fs/namei.c:149 getname+0x2c/0x40 fs/namei.c:209 [...] Allocated by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc mm/kasan/common.c:479 [inline] __kasan_kmalloc.constprop.0+0x110/0x13c mm/kasan/common.c:449 kasan_kmalloc+0xc/0x14 mm/kasan/common.c:493 kmem_cache_alloc_trace+0x440/0x924 mm/slub.c:2950 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:675 [inline] perf_event_alloc.part.0+0xb4/0x1350 kernel/events/core.c:11230 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 __arm64_sys_perf_event_open+0x6c/0x80 kernel/events/core.c:11723 [...] Freed by task 14445: kasan_save_stack+0x24/0x50 mm/kasan/common.c:48 kasan_set_track+0x24/0x34 mm/kasan/common.c:56 kasan_set_free_info+0x20/0x40 mm/kasan/generic.c:358 __kasan_slab_free.part.0+0x11c/0x1b0 mm/kasan/common.c:437 __kasan_slab_free mm/kasan/common.c:445 [inline] kasan_slab_free+0x2c/0x40 mm/kasan/common.c:446 slab_free_hook mm/slub.c:1569 [inline] slab_free_freelist_hook mm/slub.c:1608 [inline] slab_free mm/slub.c:3179 [inline] kfree+0x12c/0xc10 mm/slub.c:4176 perf_event_alloc.part.0+0xa0c/0x1350 kernel/events/core.c:11434 perf_event_alloc kernel/events/core.c:11733 [inline] __do_sys_perf_event_open kernel/events/core.c:11831 [inline] __se_sys_perf_event_open+0x550/0x15f4 kernel/events/core.c:11723 [...] Link: https://lore.kernel.org/linux-trace-kernel/20221103031010.166498-1-lihuafei… Fixes: edb096e00724f ("ftrace: Fix memleak when unregistering dynamic ops when tracing disabled") Cc: stable(a)vger.kernel.org Suggested-by: Steven Rostedt <rostedt(a)goodmis.org> Signed-off-by: Li Huafei <lihuafei1(a)huawei.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index fbf2543111c0..7dc023641bf1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3028,18 +3028,8 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) command |= FTRACE_UPDATE_TRACE_FUNC; } - if (!command || !ftrace_enabled) { - /* - * If these are dynamic or per_cpu ops, they still - * need their data freed. Since, function tracing is - * not currently active, we can just free them - * without synchronizing all CPUs. - */ - if (ops->flags & FTRACE_OPS_FL_DYNAMIC) - goto free_ops; - - return 0; - } + if (!command || !ftrace_enabled) + goto out; /* * If the ops uses a trampoline, then it needs to be @@ -3076,6 +3066,7 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) removed_ops = NULL; ops->flags &= ~FTRACE_OPS_FL_REMOVING; +out: /* * Dynamic ops may be freed, we must make sure that all * callers are done before leaving this function. @@ -3103,7 +3094,6 @@ int ftrace_shutdown(struct ftrace_ops *ops, int command) if (IS_ENABLED(CONFIG_PREEMPTION)) synchronize_rcu_tasks(); - free_ops: ftrace_trampoline_free(ops); }

2 years, 1 month

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FAILED: patch "[PATCH] btrfs: fix tree mod log mishandling of reallocated nodes" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 968b71583130 ("btrfs: fix tree mod log mishandling of reallocated nodes") 888dd183390d ("btrfs: use the new bit BTRFS_FS_TREE_MOD_LOG_USERS at btrfs_free_tree_block()") 485df7555425 ("btrfs: always pin deleted leaves when there are active tree mod log users") d3575156f662 ("btrfs: zoned: redirty released extent buffers") 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones") a94794d50d78 ("btrfs: zoned: calculate allocation offset for conventional zones") 08e11a3db098 ("btrfs: zoned: load zone's allocation offset") 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator") 760f991f1428 ("btrfs: make attach_extent_buffer_page() handle subpage case") cac06d843f25 ("btrfs: introduce the skeleton of btrfs_subpage structure") c0f0a9e71653 ("btrfs: introduce helper to grab an existing extent buffer from a page") 997e3e2e71b3 ("btrfs: only mark bg->needs_free_space if free space tree is on") 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode") 5d1ab66c56fe ("btrfs: disallow space_cache in ZONED mode") 862931c76327 ("btrfs: introduce max_zone_append_size") b70f509774ad ("btrfs: check and enable ZONED mode") 5b316468983d ("btrfs: get zone information of zoned block devices") fb22e9c4cd57 ("btrfs: use detach_page_private() in alloc_extent_buffer()") bacce86ae8a7 ("btrfs: drop unused argument step from btrfs_free_extra_devids") 0d01e247a06b ("btrfs: assert page mapping lock in attach_extent_buffer_page") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 968b71583130b6104c9f33ba60446d598e327a8b Mon Sep 17 00:00:00 2001 From: Josef Bacik <josef(a)toxicpanda.com> Date: Fri, 14 Oct 2022 08:52:46 -0400 Subject: [PATCH] btrfs: fix tree mod log mishandling of reallocated nodes We have been seeing the following panic in production kernel BUG at fs/btrfs/tree-mod-log.c:677! invalid opcode: 0000 [#1] SMP RIP: 0010:tree_mod_log_rewind+0x1b4/0x200 RSP: 0000:ffffc9002c02f890 EFLAGS: 00010293 RAX: 0000000000000003 RBX: ffff8882b448c700 RCX: 0000000000000000 RDX: 0000000000008000 RSI: 00000000000000a7 RDI: ffff88877d831c00 RBP: 0000000000000002 R08: 000000000000009f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000100c40 R12: 0000000000000001 R13: ffff8886c26d6a00 R14: ffff88829f5424f8 R15: ffff88877d831a00 FS: 00007fee1d80c780(0000) GS:ffff8890400c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee1963a020 CR3: 0000000434f33002 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: btrfs_get_old_root+0x12b/0x420 btrfs_search_old_slot+0x64/0x2f0 ? tree_mod_log_oldest_root+0x3d/0xf0 resolve_indirect_ref+0xfd/0x660 ? ulist_alloc+0x31/0x60 ? kmem_cache_alloc_trace+0x114/0x2c0 find_parent_nodes+0x97a/0x17e0 ? ulist_alloc+0x30/0x60 btrfs_find_all_roots_safe+0x97/0x150 iterate_extent_inodes+0x154/0x370 ? btrfs_search_path_in_tree+0x240/0x240 iterate_inodes_from_logical+0x98/0xd0 ? btrfs_search_path_in_tree+0x240/0x240 btrfs_ioctl_logical_to_ino+0xd9/0x180 btrfs_ioctl+0xe2/0x2ec0 ? __mod_memcg_lruvec_state+0x3d/0x280 ? do_sys_openat2+0x6d/0x140 ? kretprobe_dispatcher+0x47/0x70 ? kretprobe_rethook_handler+0x38/0x50 ? rethook_trampoline_handler+0x82/0x140 ? arch_rethook_trampoline_callback+0x3b/0x50 ? kmem_cache_free+0xfb/0x270 ? do_sys_openat2+0xd5/0x140 __x64_sys_ioctl+0x71/0xb0 do_syscall_64+0x2d/0x40 Which is this code in tree_mod_log_rewind() switch (tm->op) { case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING: BUG_ON(tm->slot < n); This occurs because we replay the nodes in order that they happened, and when we do a REPLACE we will log a REMOVE_WHILE_FREEING for every slot, starting at 0. 'n' here is the number of items in this block, which in this case was 1, but we had 2 REMOVE_WHILE_FREEING operations. The actual root cause of this was that we were replaying operations for a block that shouldn't have been replayed. Consider the following sequence of events 1. We have an already modified root, and we do a btrfs_get_tree_mod_seq(). 2. We begin removing items from this root, triggering KEY_REPLACE for it's child slots. 3. We remove one of the 2 children this root node points to, thus triggering the root node promotion of the remaining child, and freeing this node. 4. We modify a new root, and re-allocate the above node to the root node of this other root. The tree mod log looks something like this logical 0 op KEY_REPLACE (slot 1) seq 2 logical 0 op KEY_REMOVE (slot 1) seq 3 logical 0 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 4 logical 4096 op LOG_ROOT_REPLACE (old logical 0) seq 5 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 1) seq 6 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 7 logical 0 op LOG_ROOT_REPLACE (old logical 8192) seq 8 >From here the bug is triggered by the following steps 1. Call btrfs_get_old_root() on the new_root. 2. We call tree_mod_log_oldest_root(btrfs_root_node(new_root)), which is currently logical 0. 3. tree_mod_log_oldest_root() calls tree_mod_log_search_oldest(), which gives us the KEY_REPLACE seq 2, and since that's not a LOG_ROOT_REPLACE we incorrectly believe that we don't have an old root, because we expect that the most recent change should be a LOG_ROOT_REPLACE. 4. Back in tree_mod_log_oldest_root() we don't have a LOG_ROOT_REPLACE, so we don't set old_root, we simply use our existing extent buffer. 5. Since we're using our existing extent buffer (logical 0) we call tree_mod_log_search(0) in order to get the newest change to start the rewind from, which ends up being the LOG_ROOT_REPLACE at seq 8. 6. Again since we didn't find an old_root we simply clone logical 0 at it's current state. 7. We call tree_mod_log_rewind() with the cloned extent buffer. 8. Set n = btrfs_header_nritems(logical 0), which would be whatever the original nritems was when we COWed the original root, say for this example it's 2. 9. We start from the newest operation and work our way forward, so we see LOG_ROOT_REPLACE which we ignore. 10. Next we see KEY_REMOVE_WHILE_FREEING for slot 0, which triggers the BUG_ON(tm->slot < n), because it expects if we've done this we have a completely empty extent buffer to replay completely. The correct thing would be to find the first LOG_ROOT_REPLACE, and then get the old_root set to logical 8192. In fact making that change fixes this particular problem. However consider the much more complicated case. We have a child node in this tree and the above situation. In the above case we freed one of the child blocks at the seq 3 operation. If this block was also re-allocated and got new tree mod log operations we would have a different problem. btrfs_search_old_slot(orig root) would get down to the logical 0 root that still pointed at that node. However in btrfs_search_old_slot() we call tree_mod_log_rewind(buf) directly. This is not context aware enough to know which operations we should be replaying. If the block was re-allocated multiple times we may only want to replay a range of operations, and determining what that range is isn't possible to determine. We could maybe solve this by keeping track of which root the node belonged to at every tree mod log operation, and then passing this around to make sure we're only replaying operations that relate to the root we're trying to rewind. However there's a simpler way to solve this problem, simply disallow reallocations if we have currently running tree mod log users. We already do this for leaf's, so we're simply expanding this to nodes as well. This is a relatively uncommon occurrence, and the problem is complicated enough I'm worried that we will still have corner cases in the reallocation case. So fix this in the most straightforward way possible. Fixes: bd989ba359f2 ("Btrfs: add tree modification log functions") CC: stable(a)vger.kernel.org # 3.3+ Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Josef Bacik <josef(a)toxicpanda.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index cd2d36580f1a..2801c991814f 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3295,21 +3295,22 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans, } /* - * If this is a leaf and there are tree mod log users, we may - * have recorded mod log operations that point to this leaf. - * So we must make sure no one reuses this leaf's extent before - * mod log operations are applied to a node, otherwise after - * rewinding a node using the mod log operations we get an - * inconsistent btree, as the leaf's extent may now be used as - * a node or leaf for another different btree. + * If there are tree mod log users we may have recorded mod log + * operations for this node. If we re-allocate this node we + * could replay operations on this node that happened when it + * existed in a completely different root. For example if it + * was part of root A, then was reallocated to root B, and we + * are doing a btrfs_old_search_slot(root b), we could replay + * operations that happened when the block was part of root A, + * giving us an inconsistent view of the btree. + * * We are safe from races here because at this point no other * node or root points to this extent buffer, so if after this - * check a new tree mod log user joins, it will not be able to - * find a node pointing to this leaf and record operations that - * point to this leaf. + * check a new tree mod log user joins we will not have an + * existing log of operations on this node that we have to + * contend with. */ - if (btrfs_header_level(buf) == 0 && - test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) + if (test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) must_pin = true; if (must_pin || btrfs_is_zoned(fs_info)) {

2 years, 1 month

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FAILED: patch "[PATCH] btrfs: fix tree mod log mishandling of reallocated nodes" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 968b71583130 ("btrfs: fix tree mod log mishandling of reallocated nodes") 888dd183390d ("btrfs: use the new bit BTRFS_FS_TREE_MOD_LOG_USERS at btrfs_free_tree_block()") 485df7555425 ("btrfs: always pin deleted leaves when there are active tree mod log users") d3575156f662 ("btrfs: zoned: redirty released extent buffers") 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones") a94794d50d78 ("btrfs: zoned: calculate allocation offset for conventional zones") 08e11a3db098 ("btrfs: zoned: load zone's allocation offset") 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator") 760f991f1428 ("btrfs: make attach_extent_buffer_page() handle subpage case") cac06d843f25 ("btrfs: introduce the skeleton of btrfs_subpage structure") c0f0a9e71653 ("btrfs: introduce helper to grab an existing extent buffer from a page") 997e3e2e71b3 ("btrfs: only mark bg->needs_free_space if free space tree is on") 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode") 5d1ab66c56fe ("btrfs: disallow space_cache in ZONED mode") 862931c76327 ("btrfs: introduce max_zone_append_size") b70f509774ad ("btrfs: check and enable ZONED mode") 5b316468983d ("btrfs: get zone information of zoned block devices") fb22e9c4cd57 ("btrfs: use detach_page_private() in alloc_extent_buffer()") bacce86ae8a7 ("btrfs: drop unused argument step from btrfs_free_extra_devids") 0d01e247a06b ("btrfs: assert page mapping lock in attach_extent_buffer_page") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 968b71583130b6104c9f33ba60446d598e327a8b Mon Sep 17 00:00:00 2001 From: Josef Bacik <josef(a)toxicpanda.com> Date: Fri, 14 Oct 2022 08:52:46 -0400 Subject: [PATCH] btrfs: fix tree mod log mishandling of reallocated nodes We have been seeing the following panic in production kernel BUG at fs/btrfs/tree-mod-log.c:677! invalid opcode: 0000 [#1] SMP RIP: 0010:tree_mod_log_rewind+0x1b4/0x200 RSP: 0000:ffffc9002c02f890 EFLAGS: 00010293 RAX: 0000000000000003 RBX: ffff8882b448c700 RCX: 0000000000000000 RDX: 0000000000008000 RSI: 00000000000000a7 RDI: ffff88877d831c00 RBP: 0000000000000002 R08: 000000000000009f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000100c40 R12: 0000000000000001 R13: ffff8886c26d6a00 R14: ffff88829f5424f8 R15: ffff88877d831a00 FS: 00007fee1d80c780(0000) GS:ffff8890400c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee1963a020 CR3: 0000000434f33002 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: btrfs_get_old_root+0x12b/0x420 btrfs_search_old_slot+0x64/0x2f0 ? tree_mod_log_oldest_root+0x3d/0xf0 resolve_indirect_ref+0xfd/0x660 ? ulist_alloc+0x31/0x60 ? kmem_cache_alloc_trace+0x114/0x2c0 find_parent_nodes+0x97a/0x17e0 ? ulist_alloc+0x30/0x60 btrfs_find_all_roots_safe+0x97/0x150 iterate_extent_inodes+0x154/0x370 ? btrfs_search_path_in_tree+0x240/0x240 iterate_inodes_from_logical+0x98/0xd0 ? btrfs_search_path_in_tree+0x240/0x240 btrfs_ioctl_logical_to_ino+0xd9/0x180 btrfs_ioctl+0xe2/0x2ec0 ? __mod_memcg_lruvec_state+0x3d/0x280 ? do_sys_openat2+0x6d/0x140 ? kretprobe_dispatcher+0x47/0x70 ? kretprobe_rethook_handler+0x38/0x50 ? rethook_trampoline_handler+0x82/0x140 ? arch_rethook_trampoline_callback+0x3b/0x50 ? kmem_cache_free+0xfb/0x270 ? do_sys_openat2+0xd5/0x140 __x64_sys_ioctl+0x71/0xb0 do_syscall_64+0x2d/0x40 Which is this code in tree_mod_log_rewind() switch (tm->op) { case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING: BUG_ON(tm->slot < n); This occurs because we replay the nodes in order that they happened, and when we do a REPLACE we will log a REMOVE_WHILE_FREEING for every slot, starting at 0. 'n' here is the number of items in this block, which in this case was 1, but we had 2 REMOVE_WHILE_FREEING operations. The actual root cause of this was that we were replaying operations for a block that shouldn't have been replayed. Consider the following sequence of events 1. We have an already modified root, and we do a btrfs_get_tree_mod_seq(). 2. We begin removing items from this root, triggering KEY_REPLACE for it's child slots. 3. We remove one of the 2 children this root node points to, thus triggering the root node promotion of the remaining child, and freeing this node. 4. We modify a new root, and re-allocate the above node to the root node of this other root. The tree mod log looks something like this logical 0 op KEY_REPLACE (slot 1) seq 2 logical 0 op KEY_REMOVE (slot 1) seq 3 logical 0 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 4 logical 4096 op LOG_ROOT_REPLACE (old logical 0) seq 5 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 1) seq 6 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 7 logical 0 op LOG_ROOT_REPLACE (old logical 8192) seq 8 >From here the bug is triggered by the following steps 1. Call btrfs_get_old_root() on the new_root. 2. We call tree_mod_log_oldest_root(btrfs_root_node(new_root)), which is currently logical 0. 3. tree_mod_log_oldest_root() calls tree_mod_log_search_oldest(), which gives us the KEY_REPLACE seq 2, and since that's not a LOG_ROOT_REPLACE we incorrectly believe that we don't have an old root, because we expect that the most recent change should be a LOG_ROOT_REPLACE. 4. Back in tree_mod_log_oldest_root() we don't have a LOG_ROOT_REPLACE, so we don't set old_root, we simply use our existing extent buffer. 5. Since we're using our existing extent buffer (logical 0) we call tree_mod_log_search(0) in order to get the newest change to start the rewind from, which ends up being the LOG_ROOT_REPLACE at seq 8. 6. Again since we didn't find an old_root we simply clone logical 0 at it's current state. 7. We call tree_mod_log_rewind() with the cloned extent buffer. 8. Set n = btrfs_header_nritems(logical 0), which would be whatever the original nritems was when we COWed the original root, say for this example it's 2. 9. We start from the newest operation and work our way forward, so we see LOG_ROOT_REPLACE which we ignore. 10. Next we see KEY_REMOVE_WHILE_FREEING for slot 0, which triggers the BUG_ON(tm->slot < n), because it expects if we've done this we have a completely empty extent buffer to replay completely. The correct thing would be to find the first LOG_ROOT_REPLACE, and then get the old_root set to logical 8192. In fact making that change fixes this particular problem. However consider the much more complicated case. We have a child node in this tree and the above situation. In the above case we freed one of the child blocks at the seq 3 operation. If this block was also re-allocated and got new tree mod log operations we would have a different problem. btrfs_search_old_slot(orig root) would get down to the logical 0 root that still pointed at that node. However in btrfs_search_old_slot() we call tree_mod_log_rewind(buf) directly. This is not context aware enough to know which operations we should be replaying. If the block was re-allocated multiple times we may only want to replay a range of operations, and determining what that range is isn't possible to determine. We could maybe solve this by keeping track of which root the node belonged to at every tree mod log operation, and then passing this around to make sure we're only replaying operations that relate to the root we're trying to rewind. However there's a simpler way to solve this problem, simply disallow reallocations if we have currently running tree mod log users. We already do this for leaf's, so we're simply expanding this to nodes as well. This is a relatively uncommon occurrence, and the problem is complicated enough I'm worried that we will still have corner cases in the reallocation case. So fix this in the most straightforward way possible. Fixes: bd989ba359f2 ("Btrfs: add tree modification log functions") CC: stable(a)vger.kernel.org # 3.3+ Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Josef Bacik <josef(a)toxicpanda.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index cd2d36580f1a..2801c991814f 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3295,21 +3295,22 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans, } /* - * If this is a leaf and there are tree mod log users, we may - * have recorded mod log operations that point to this leaf. - * So we must make sure no one reuses this leaf's extent before - * mod log operations are applied to a node, otherwise after - * rewinding a node using the mod log operations we get an - * inconsistent btree, as the leaf's extent may now be used as - * a node or leaf for another different btree. + * If there are tree mod log users we may have recorded mod log + * operations for this node. If we re-allocate this node we + * could replay operations on this node that happened when it + * existed in a completely different root. For example if it + * was part of root A, then was reallocated to root B, and we + * are doing a btrfs_old_search_slot(root b), we could replay + * operations that happened when the block was part of root A, + * giving us an inconsistent view of the btree. + * * We are safe from races here because at this point no other * node or root points to this extent buffer, so if after this - * check a new tree mod log user joins, it will not be able to - * find a node pointing to this leaf and record operations that - * point to this leaf. + * check a new tree mod log user joins we will not have an + * existing log of operations on this node that we have to + * contend with. */ - if (btrfs_header_level(buf) == 0 && - test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) + if (test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) must_pin = true; if (must_pin || btrfs_is_zoned(fs_info)) {

2 years, 1 month

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FAILED: patch "[PATCH] btrfs: fix tree mod log mishandling of reallocated nodes" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 968b71583130 ("btrfs: fix tree mod log mishandling of reallocated nodes") 888dd183390d ("btrfs: use the new bit BTRFS_FS_TREE_MOD_LOG_USERS at btrfs_free_tree_block()") 485df7555425 ("btrfs: always pin deleted leaves when there are active tree mod log users") d3575156f662 ("btrfs: zoned: redirty released extent buffers") 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones") a94794d50d78 ("btrfs: zoned: calculate allocation offset for conventional zones") 08e11a3db098 ("btrfs: zoned: load zone's allocation offset") 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator") 760f991f1428 ("btrfs: make attach_extent_buffer_page() handle subpage case") cac06d843f25 ("btrfs: introduce the skeleton of btrfs_subpage structure") c0f0a9e71653 ("btrfs: introduce helper to grab an existing extent buffer from a page") 997e3e2e71b3 ("btrfs: only mark bg->needs_free_space if free space tree is on") 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode") 5d1ab66c56fe ("btrfs: disallow space_cache in ZONED mode") 862931c76327 ("btrfs: introduce max_zone_append_size") b70f509774ad ("btrfs: check and enable ZONED mode") 5b316468983d ("btrfs: get zone information of zoned block devices") fb22e9c4cd57 ("btrfs: use detach_page_private() in alloc_extent_buffer()") bacce86ae8a7 ("btrfs: drop unused argument step from btrfs_free_extra_devids") 0d01e247a06b ("btrfs: assert page mapping lock in attach_extent_buffer_page") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 968b71583130b6104c9f33ba60446d598e327a8b Mon Sep 17 00:00:00 2001 From: Josef Bacik <josef(a)toxicpanda.com> Date: Fri, 14 Oct 2022 08:52:46 -0400 Subject: [PATCH] btrfs: fix tree mod log mishandling of reallocated nodes We have been seeing the following panic in production kernel BUG at fs/btrfs/tree-mod-log.c:677! invalid opcode: 0000 [#1] SMP RIP: 0010:tree_mod_log_rewind+0x1b4/0x200 RSP: 0000:ffffc9002c02f890 EFLAGS: 00010293 RAX: 0000000000000003 RBX: ffff8882b448c700 RCX: 0000000000000000 RDX: 0000000000008000 RSI: 00000000000000a7 RDI: ffff88877d831c00 RBP: 0000000000000002 R08: 000000000000009f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000100c40 R12: 0000000000000001 R13: ffff8886c26d6a00 R14: ffff88829f5424f8 R15: ffff88877d831a00 FS: 00007fee1d80c780(0000) GS:ffff8890400c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee1963a020 CR3: 0000000434f33002 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: btrfs_get_old_root+0x12b/0x420 btrfs_search_old_slot+0x64/0x2f0 ? tree_mod_log_oldest_root+0x3d/0xf0 resolve_indirect_ref+0xfd/0x660 ? ulist_alloc+0x31/0x60 ? kmem_cache_alloc_trace+0x114/0x2c0 find_parent_nodes+0x97a/0x17e0 ? ulist_alloc+0x30/0x60 btrfs_find_all_roots_safe+0x97/0x150 iterate_extent_inodes+0x154/0x370 ? btrfs_search_path_in_tree+0x240/0x240 iterate_inodes_from_logical+0x98/0xd0 ? btrfs_search_path_in_tree+0x240/0x240 btrfs_ioctl_logical_to_ino+0xd9/0x180 btrfs_ioctl+0xe2/0x2ec0 ? __mod_memcg_lruvec_state+0x3d/0x280 ? do_sys_openat2+0x6d/0x140 ? kretprobe_dispatcher+0x47/0x70 ? kretprobe_rethook_handler+0x38/0x50 ? rethook_trampoline_handler+0x82/0x140 ? arch_rethook_trampoline_callback+0x3b/0x50 ? kmem_cache_free+0xfb/0x270 ? do_sys_openat2+0xd5/0x140 __x64_sys_ioctl+0x71/0xb0 do_syscall_64+0x2d/0x40 Which is this code in tree_mod_log_rewind() switch (tm->op) { case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING: BUG_ON(tm->slot < n); This occurs because we replay the nodes in order that they happened, and when we do a REPLACE we will log a REMOVE_WHILE_FREEING for every slot, starting at 0. 'n' here is the number of items in this block, which in this case was 1, but we had 2 REMOVE_WHILE_FREEING operations. The actual root cause of this was that we were replaying operations for a block that shouldn't have been replayed. Consider the following sequence of events 1. We have an already modified root, and we do a btrfs_get_tree_mod_seq(). 2. We begin removing items from this root, triggering KEY_REPLACE for it's child slots. 3. We remove one of the 2 children this root node points to, thus triggering the root node promotion of the remaining child, and freeing this node. 4. We modify a new root, and re-allocate the above node to the root node of this other root. The tree mod log looks something like this logical 0 op KEY_REPLACE (slot 1) seq 2 logical 0 op KEY_REMOVE (slot 1) seq 3 logical 0 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 4 logical 4096 op LOG_ROOT_REPLACE (old logical 0) seq 5 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 1) seq 6 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 7 logical 0 op LOG_ROOT_REPLACE (old logical 8192) seq 8 >From here the bug is triggered by the following steps 1. Call btrfs_get_old_root() on the new_root. 2. We call tree_mod_log_oldest_root(btrfs_root_node(new_root)), which is currently logical 0. 3. tree_mod_log_oldest_root() calls tree_mod_log_search_oldest(), which gives us the KEY_REPLACE seq 2, and since that's not a LOG_ROOT_REPLACE we incorrectly believe that we don't have an old root, because we expect that the most recent change should be a LOG_ROOT_REPLACE. 4. Back in tree_mod_log_oldest_root() we don't have a LOG_ROOT_REPLACE, so we don't set old_root, we simply use our existing extent buffer. 5. Since we're using our existing extent buffer (logical 0) we call tree_mod_log_search(0) in order to get the newest change to start the rewind from, which ends up being the LOG_ROOT_REPLACE at seq 8. 6. Again since we didn't find an old_root we simply clone logical 0 at it's current state. 7. We call tree_mod_log_rewind() with the cloned extent buffer. 8. Set n = btrfs_header_nritems(logical 0), which would be whatever the original nritems was when we COWed the original root, say for this example it's 2. 9. We start from the newest operation and work our way forward, so we see LOG_ROOT_REPLACE which we ignore. 10. Next we see KEY_REMOVE_WHILE_FREEING for slot 0, which triggers the BUG_ON(tm->slot < n), because it expects if we've done this we have a completely empty extent buffer to replay completely. The correct thing would be to find the first LOG_ROOT_REPLACE, and then get the old_root set to logical 8192. In fact making that change fixes this particular problem. However consider the much more complicated case. We have a child node in this tree and the above situation. In the above case we freed one of the child blocks at the seq 3 operation. If this block was also re-allocated and got new tree mod log operations we would have a different problem. btrfs_search_old_slot(orig root) would get down to the logical 0 root that still pointed at that node. However in btrfs_search_old_slot() we call tree_mod_log_rewind(buf) directly. This is not context aware enough to know which operations we should be replaying. If the block was re-allocated multiple times we may only want to replay a range of operations, and determining what that range is isn't possible to determine. We could maybe solve this by keeping track of which root the node belonged to at every tree mod log operation, and then passing this around to make sure we're only replaying operations that relate to the root we're trying to rewind. However there's a simpler way to solve this problem, simply disallow reallocations if we have currently running tree mod log users. We already do this for leaf's, so we're simply expanding this to nodes as well. This is a relatively uncommon occurrence, and the problem is complicated enough I'm worried that we will still have corner cases in the reallocation case. So fix this in the most straightforward way possible. Fixes: bd989ba359f2 ("Btrfs: add tree modification log functions") CC: stable(a)vger.kernel.org # 3.3+ Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Josef Bacik <josef(a)toxicpanda.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index cd2d36580f1a..2801c991814f 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3295,21 +3295,22 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans, } /* - * If this is a leaf and there are tree mod log users, we may - * have recorded mod log operations that point to this leaf. - * So we must make sure no one reuses this leaf's extent before - * mod log operations are applied to a node, otherwise after - * rewinding a node using the mod log operations we get an - * inconsistent btree, as the leaf's extent may now be used as - * a node or leaf for another different btree. + * If there are tree mod log users we may have recorded mod log + * operations for this node. If we re-allocate this node we + * could replay operations on this node that happened when it + * existed in a completely different root. For example if it + * was part of root A, then was reallocated to root B, and we + * are doing a btrfs_old_search_slot(root b), we could replay + * operations that happened when the block was part of root A, + * giving us an inconsistent view of the btree. + * * We are safe from races here because at this point no other * node or root points to this extent buffer, so if after this - * check a new tree mod log user joins, it will not be able to - * find a node pointing to this leaf and record operations that - * point to this leaf. + * check a new tree mod log user joins we will not have an + * existing log of operations on this node that we have to + * contend with. */ - if (btrfs_header_level(buf) == 0 && - test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) + if (test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) must_pin = true; if (must_pin || btrfs_is_zoned(fs_info)) {

2 years, 1 month

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FAILED: patch "[PATCH] btrfs: fix tree mod log mishandling of reallocated nodes" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 968b71583130 ("btrfs: fix tree mod log mishandling of reallocated nodes") 888dd183390d ("btrfs: use the new bit BTRFS_FS_TREE_MOD_LOG_USERS at btrfs_free_tree_block()") 485df7555425 ("btrfs: always pin deleted leaves when there are active tree mod log users") d3575156f662 ("btrfs: zoned: redirty released extent buffers") 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones") a94794d50d78 ("btrfs: zoned: calculate allocation offset for conventional zones") 08e11a3db098 ("btrfs: zoned: load zone's allocation offset") 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator") 760f991f1428 ("btrfs: make attach_extent_buffer_page() handle subpage case") cac06d843f25 ("btrfs: introduce the skeleton of btrfs_subpage structure") c0f0a9e71653 ("btrfs: introduce helper to grab an existing extent buffer from a page") 997e3e2e71b3 ("btrfs: only mark bg->needs_free_space if free space tree is on") 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode") 5d1ab66c56fe ("btrfs: disallow space_cache in ZONED mode") 862931c76327 ("btrfs: introduce max_zone_append_size") b70f509774ad ("btrfs: check and enable ZONED mode") 5b316468983d ("btrfs: get zone information of zoned block devices") fb22e9c4cd57 ("btrfs: use detach_page_private() in alloc_extent_buffer()") bacce86ae8a7 ("btrfs: drop unused argument step from btrfs_free_extra_devids") 0d01e247a06b ("btrfs: assert page mapping lock in attach_extent_buffer_page") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 968b71583130b6104c9f33ba60446d598e327a8b Mon Sep 17 00:00:00 2001 From: Josef Bacik <josef(a)toxicpanda.com> Date: Fri, 14 Oct 2022 08:52:46 -0400 Subject: [PATCH] btrfs: fix tree mod log mishandling of reallocated nodes We have been seeing the following panic in production kernel BUG at fs/btrfs/tree-mod-log.c:677! invalid opcode: 0000 [#1] SMP RIP: 0010:tree_mod_log_rewind+0x1b4/0x200 RSP: 0000:ffffc9002c02f890 EFLAGS: 00010293 RAX: 0000000000000003 RBX: ffff8882b448c700 RCX: 0000000000000000 RDX: 0000000000008000 RSI: 00000000000000a7 RDI: ffff88877d831c00 RBP: 0000000000000002 R08: 000000000000009f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000100c40 R12: 0000000000000001 R13: ffff8886c26d6a00 R14: ffff88829f5424f8 R15: ffff88877d831a00 FS: 00007fee1d80c780(0000) GS:ffff8890400c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee1963a020 CR3: 0000000434f33002 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: btrfs_get_old_root+0x12b/0x420 btrfs_search_old_slot+0x64/0x2f0 ? tree_mod_log_oldest_root+0x3d/0xf0 resolve_indirect_ref+0xfd/0x660 ? ulist_alloc+0x31/0x60 ? kmem_cache_alloc_trace+0x114/0x2c0 find_parent_nodes+0x97a/0x17e0 ? ulist_alloc+0x30/0x60 btrfs_find_all_roots_safe+0x97/0x150 iterate_extent_inodes+0x154/0x370 ? btrfs_search_path_in_tree+0x240/0x240 iterate_inodes_from_logical+0x98/0xd0 ? btrfs_search_path_in_tree+0x240/0x240 btrfs_ioctl_logical_to_ino+0xd9/0x180 btrfs_ioctl+0xe2/0x2ec0 ? __mod_memcg_lruvec_state+0x3d/0x280 ? do_sys_openat2+0x6d/0x140 ? kretprobe_dispatcher+0x47/0x70 ? kretprobe_rethook_handler+0x38/0x50 ? rethook_trampoline_handler+0x82/0x140 ? arch_rethook_trampoline_callback+0x3b/0x50 ? kmem_cache_free+0xfb/0x270 ? do_sys_openat2+0xd5/0x140 __x64_sys_ioctl+0x71/0xb0 do_syscall_64+0x2d/0x40 Which is this code in tree_mod_log_rewind() switch (tm->op) { case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING: BUG_ON(tm->slot < n); This occurs because we replay the nodes in order that they happened, and when we do a REPLACE we will log a REMOVE_WHILE_FREEING for every slot, starting at 0. 'n' here is the number of items in this block, which in this case was 1, but we had 2 REMOVE_WHILE_FREEING operations. The actual root cause of this was that we were replaying operations for a block that shouldn't have been replayed. Consider the following sequence of events 1. We have an already modified root, and we do a btrfs_get_tree_mod_seq(). 2. We begin removing items from this root, triggering KEY_REPLACE for it's child slots. 3. We remove one of the 2 children this root node points to, thus triggering the root node promotion of the remaining child, and freeing this node. 4. We modify a new root, and re-allocate the above node to the root node of this other root. The tree mod log looks something like this logical 0 op KEY_REPLACE (slot 1) seq 2 logical 0 op KEY_REMOVE (slot 1) seq 3 logical 0 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 4 logical 4096 op LOG_ROOT_REPLACE (old logical 0) seq 5 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 1) seq 6 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 7 logical 0 op LOG_ROOT_REPLACE (old logical 8192) seq 8 >From here the bug is triggered by the following steps 1. Call btrfs_get_old_root() on the new_root. 2. We call tree_mod_log_oldest_root(btrfs_root_node(new_root)), which is currently logical 0. 3. tree_mod_log_oldest_root() calls tree_mod_log_search_oldest(), which gives us the KEY_REPLACE seq 2, and since that's not a LOG_ROOT_REPLACE we incorrectly believe that we don't have an old root, because we expect that the most recent change should be a LOG_ROOT_REPLACE. 4. Back in tree_mod_log_oldest_root() we don't have a LOG_ROOT_REPLACE, so we don't set old_root, we simply use our existing extent buffer. 5. Since we're using our existing extent buffer (logical 0) we call tree_mod_log_search(0) in order to get the newest change to start the rewind from, which ends up being the LOG_ROOT_REPLACE at seq 8. 6. Again since we didn't find an old_root we simply clone logical 0 at it's current state. 7. We call tree_mod_log_rewind() with the cloned extent buffer. 8. Set n = btrfs_header_nritems(logical 0), which would be whatever the original nritems was when we COWed the original root, say for this example it's 2. 9. We start from the newest operation and work our way forward, so we see LOG_ROOT_REPLACE which we ignore. 10. Next we see KEY_REMOVE_WHILE_FREEING for slot 0, which triggers the BUG_ON(tm->slot < n), because it expects if we've done this we have a completely empty extent buffer to replay completely. The correct thing would be to find the first LOG_ROOT_REPLACE, and then get the old_root set to logical 8192. In fact making that change fixes this particular problem. However consider the much more complicated case. We have a child node in this tree and the above situation. In the above case we freed one of the child blocks at the seq 3 operation. If this block was also re-allocated and got new tree mod log operations we would have a different problem. btrfs_search_old_slot(orig root) would get down to the logical 0 root that still pointed at that node. However in btrfs_search_old_slot() we call tree_mod_log_rewind(buf) directly. This is not context aware enough to know which operations we should be replaying. If the block was re-allocated multiple times we may only want to replay a range of operations, and determining what that range is isn't possible to determine. We could maybe solve this by keeping track of which root the node belonged to at every tree mod log operation, and then passing this around to make sure we're only replaying operations that relate to the root we're trying to rewind. However there's a simpler way to solve this problem, simply disallow reallocations if we have currently running tree mod log users. We already do this for leaf's, so we're simply expanding this to nodes as well. This is a relatively uncommon occurrence, and the problem is complicated enough I'm worried that we will still have corner cases in the reallocation case. So fix this in the most straightforward way possible. Fixes: bd989ba359f2 ("Btrfs: add tree modification log functions") CC: stable(a)vger.kernel.org # 3.3+ Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Josef Bacik <josef(a)toxicpanda.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index cd2d36580f1a..2801c991814f 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3295,21 +3295,22 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans, } /* - * If this is a leaf and there are tree mod log users, we may - * have recorded mod log operations that point to this leaf. - * So we must make sure no one reuses this leaf's extent before - * mod log operations are applied to a node, otherwise after - * rewinding a node using the mod log operations we get an - * inconsistent btree, as the leaf's extent may now be used as - * a node or leaf for another different btree. + * If there are tree mod log users we may have recorded mod log + * operations for this node. If we re-allocate this node we + * could replay operations on this node that happened when it + * existed in a completely different root. For example if it + * was part of root A, then was reallocated to root B, and we + * are doing a btrfs_old_search_slot(root b), we could replay + * operations that happened when the block was part of root A, + * giving us an inconsistent view of the btree. + * * We are safe from races here because at this point no other * node or root points to this extent buffer, so if after this - * check a new tree mod log user joins, it will not be able to - * find a node pointing to this leaf and record operations that - * point to this leaf. + * check a new tree mod log user joins we will not have an + * existing log of operations on this node that we have to + * contend with. */ - if (btrfs_header_level(buf) == 0 && - test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) + if (test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) must_pin = true; if (must_pin || btrfs_is_zoned(fs_info)) {

2 years, 1 month

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FAILED: patch "[PATCH] btrfs: fix tree mod log mishandling of reallocated nodes" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. Possible dependencies: 968b71583130 ("btrfs: fix tree mod log mishandling of reallocated nodes") 888dd183390d ("btrfs: use the new bit BTRFS_FS_TREE_MOD_LOG_USERS at btrfs_free_tree_block()") 485df7555425 ("btrfs: always pin deleted leaves when there are active tree mod log users") d3575156f662 ("btrfs: zoned: redirty released extent buffers") 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones") a94794d50d78 ("btrfs: zoned: calculate allocation offset for conventional zones") 08e11a3db098 ("btrfs: zoned: load zone's allocation offset") 1cd6121f2a38 ("btrfs: zoned: implement zoned chunk allocator") 760f991f1428 ("btrfs: make attach_extent_buffer_page() handle subpage case") cac06d843f25 ("btrfs: introduce the skeleton of btrfs_subpage structure") c0f0a9e71653 ("btrfs: introduce helper to grab an existing extent buffer from a page") 997e3e2e71b3 ("btrfs: only mark bg->needs_free_space if free space tree is on") 12659251ca5d ("btrfs: implement log-structured superblock for ZONED mode") 5d1ab66c56fe ("btrfs: disallow space_cache in ZONED mode") 862931c76327 ("btrfs: introduce max_zone_append_size") b70f509774ad ("btrfs: check and enable ZONED mode") 5b316468983d ("btrfs: get zone information of zoned block devices") fb22e9c4cd57 ("btrfs: use detach_page_private() in alloc_extent_buffer()") bacce86ae8a7 ("btrfs: drop unused argument step from btrfs_free_extra_devids") 0d01e247a06b ("btrfs: assert page mapping lock in attach_extent_buffer_page") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 968b71583130b6104c9f33ba60446d598e327a8b Mon Sep 17 00:00:00 2001 From: Josef Bacik <josef(a)toxicpanda.com> Date: Fri, 14 Oct 2022 08:52:46 -0400 Subject: [PATCH] btrfs: fix tree mod log mishandling of reallocated nodes We have been seeing the following panic in production kernel BUG at fs/btrfs/tree-mod-log.c:677! invalid opcode: 0000 [#1] SMP RIP: 0010:tree_mod_log_rewind+0x1b4/0x200 RSP: 0000:ffffc9002c02f890 EFLAGS: 00010293 RAX: 0000000000000003 RBX: ffff8882b448c700 RCX: 0000000000000000 RDX: 0000000000008000 RSI: 00000000000000a7 RDI: ffff88877d831c00 RBP: 0000000000000002 R08: 000000000000009f R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000100c40 R12: 0000000000000001 R13: ffff8886c26d6a00 R14: ffff88829f5424f8 R15: ffff88877d831a00 FS: 00007fee1d80c780(0000) GS:ffff8890400c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee1963a020 CR3: 0000000434f33002 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: btrfs_get_old_root+0x12b/0x420 btrfs_search_old_slot+0x64/0x2f0 ? tree_mod_log_oldest_root+0x3d/0xf0 resolve_indirect_ref+0xfd/0x660 ? ulist_alloc+0x31/0x60 ? kmem_cache_alloc_trace+0x114/0x2c0 find_parent_nodes+0x97a/0x17e0 ? ulist_alloc+0x30/0x60 btrfs_find_all_roots_safe+0x97/0x150 iterate_extent_inodes+0x154/0x370 ? btrfs_search_path_in_tree+0x240/0x240 iterate_inodes_from_logical+0x98/0xd0 ? btrfs_search_path_in_tree+0x240/0x240 btrfs_ioctl_logical_to_ino+0xd9/0x180 btrfs_ioctl+0xe2/0x2ec0 ? __mod_memcg_lruvec_state+0x3d/0x280 ? do_sys_openat2+0x6d/0x140 ? kretprobe_dispatcher+0x47/0x70 ? kretprobe_rethook_handler+0x38/0x50 ? rethook_trampoline_handler+0x82/0x140 ? arch_rethook_trampoline_callback+0x3b/0x50 ? kmem_cache_free+0xfb/0x270 ? do_sys_openat2+0xd5/0x140 __x64_sys_ioctl+0x71/0xb0 do_syscall_64+0x2d/0x40 Which is this code in tree_mod_log_rewind() switch (tm->op) { case BTRFS_MOD_LOG_KEY_REMOVE_WHILE_FREEING: BUG_ON(tm->slot < n); This occurs because we replay the nodes in order that they happened, and when we do a REPLACE we will log a REMOVE_WHILE_FREEING for every slot, starting at 0. 'n' here is the number of items in this block, which in this case was 1, but we had 2 REMOVE_WHILE_FREEING operations. The actual root cause of this was that we were replaying operations for a block that shouldn't have been replayed. Consider the following sequence of events 1. We have an already modified root, and we do a btrfs_get_tree_mod_seq(). 2. We begin removing items from this root, triggering KEY_REPLACE for it's child slots. 3. We remove one of the 2 children this root node points to, thus triggering the root node promotion of the remaining child, and freeing this node. 4. We modify a new root, and re-allocate the above node to the root node of this other root. The tree mod log looks something like this logical 0 op KEY_REPLACE (slot 1) seq 2 logical 0 op KEY_REMOVE (slot 1) seq 3 logical 0 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 4 logical 4096 op LOG_ROOT_REPLACE (old logical 0) seq 5 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 1) seq 6 logical 8192 op KEY_REMOVE_WHILE_FREEING (slot 0) seq 7 logical 0 op LOG_ROOT_REPLACE (old logical 8192) seq 8 >From here the bug is triggered by the following steps 1. Call btrfs_get_old_root() on the new_root. 2. We call tree_mod_log_oldest_root(btrfs_root_node(new_root)), which is currently logical 0. 3. tree_mod_log_oldest_root() calls tree_mod_log_search_oldest(), which gives us the KEY_REPLACE seq 2, and since that's not a LOG_ROOT_REPLACE we incorrectly believe that we don't have an old root, because we expect that the most recent change should be a LOG_ROOT_REPLACE. 4. Back in tree_mod_log_oldest_root() we don't have a LOG_ROOT_REPLACE, so we don't set old_root, we simply use our existing extent buffer. 5. Since we're using our existing extent buffer (logical 0) we call tree_mod_log_search(0) in order to get the newest change to start the rewind from, which ends up being the LOG_ROOT_REPLACE at seq 8. 6. Again since we didn't find an old_root we simply clone logical 0 at it's current state. 7. We call tree_mod_log_rewind() with the cloned extent buffer. 8. Set n = btrfs_header_nritems(logical 0), which would be whatever the original nritems was when we COWed the original root, say for this example it's 2. 9. We start from the newest operation and work our way forward, so we see LOG_ROOT_REPLACE which we ignore. 10. Next we see KEY_REMOVE_WHILE_FREEING for slot 0, which triggers the BUG_ON(tm->slot < n), because it expects if we've done this we have a completely empty extent buffer to replay completely. The correct thing would be to find the first LOG_ROOT_REPLACE, and then get the old_root set to logical 8192. In fact making that change fixes this particular problem. However consider the much more complicated case. We have a child node in this tree and the above situation. In the above case we freed one of the child blocks at the seq 3 operation. If this block was also re-allocated and got new tree mod log operations we would have a different problem. btrfs_search_old_slot(orig root) would get down to the logical 0 root that still pointed at that node. However in btrfs_search_old_slot() we call tree_mod_log_rewind(buf) directly. This is not context aware enough to know which operations we should be replaying. If the block was re-allocated multiple times we may only want to replay a range of operations, and determining what that range is isn't possible to determine. We could maybe solve this by keeping track of which root the node belonged to at every tree mod log operation, and then passing this around to make sure we're only replaying operations that relate to the root we're trying to rewind. However there's a simpler way to solve this problem, simply disallow reallocations if we have currently running tree mod log users. We already do this for leaf's, so we're simply expanding this to nodes as well. This is a relatively uncommon occurrence, and the problem is complicated enough I'm worried that we will still have corner cases in the reallocation case. So fix this in the most straightforward way possible. Fixes: bd989ba359f2 ("Btrfs: add tree modification log functions") CC: stable(a)vger.kernel.org # 3.3+ Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Josef Bacik <josef(a)toxicpanda.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index cd2d36580f1a..2801c991814f 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3295,21 +3295,22 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans, } /* - * If this is a leaf and there are tree mod log users, we may - * have recorded mod log operations that point to this leaf. - * So we must make sure no one reuses this leaf's extent before - * mod log operations are applied to a node, otherwise after - * rewinding a node using the mod log operations we get an - * inconsistent btree, as the leaf's extent may now be used as - * a node or leaf for another different btree. + * If there are tree mod log users we may have recorded mod log + * operations for this node. If we re-allocate this node we + * could replay operations on this node that happened when it + * existed in a completely different root. For example if it + * was part of root A, then was reallocated to root B, and we + * are doing a btrfs_old_search_slot(root b), we could replay + * operations that happened when the block was part of root A, + * giving us an inconsistent view of the btree. + * * We are safe from races here because at this point no other * node or root points to this extent buffer, so if after this - * check a new tree mod log user joins, it will not be able to - * find a node pointing to this leaf and record operations that - * point to this leaf. + * check a new tree mod log user joins we will not have an + * existing log of operations on this node that we have to + * contend with. */ - if (btrfs_header_level(buf) == 0 && - test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) + if (test_bit(BTRFS_FS_TREE_MOD_LOG_USERS, &fs_info->flags)) must_pin = true; if (must_pin || btrfs_is_zoned(fs_info)) {

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