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[PATCH v5.10] vhost-scsi: protect vq->log_used with vq->mutex

by Xinyu Zheng

From: Dongli Zhang <dongli.zhang(a)oracle.com> [ Upstream commit f591cf9fce724e5075cc67488c43c6e39e8cbe27 ] The vhost-scsi completion path may access vq->log_base when vq->log_used is already set to false. vhost-thread QEMU-thread vhost_scsi_complete_cmd_work() -> vhost_add_used() -> vhost_add_used_n() if (unlikely(vq->log_used)) QEMU disables vq->log_used via VHOST_SET_VRING_ADDR. mutex_lock(&vq->mutex); vq->log_used = false now! mutex_unlock(&vq->mutex); QEMU gfree(vq->log_base) log_used() -> log_write(vq->log_base) Assuming the VMM is QEMU. The vq->log_base is from QEMU userpace and can be reclaimed via gfree(). As a result, this causes invalid memory writes to QEMU userspace. The control queue path has the same issue. CVE-2025-38074 Cc: stable(a)vger.kernel.org#5.10.x Cc: gregkh(a)linuxfoundation.org Signed-off-by: Dongli Zhang <dongli.zhang(a)oracle.com> Acked-by: Jason Wang <jasowang(a)redhat.com> Reviewed-by: Mike Christie <michael.christie(a)oracle.com> Message-Id: <20250403063028.16045-2-dongli.zhang(a)oracle.com> Signed-off-by: Michael S. Tsirkin <mst(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> [ Conflicts in drivers/vhost/scsi.c bacause vhost_scsi_complete_cmd_work() has been refactored. ] Signed-off-by: Xinyu Zheng <zhengxinyu6(a)huawei.com> --- drivers/vhost/scsi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index a23a65e7d828..fcde3752b4f1 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -579,8 +579,10 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter); if (likely(ret == sizeof(v_rsp))) { struct vhost_scsi_virtqueue *q; - vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0); q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq); + mutex_lock(&q->vq.mutex); + vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0); + mutex_unlock(&q->vq.mutex); vq = q - vs->vqs; __set_bit(vq, signal); } else @@ -1193,8 +1195,11 @@ static void vhost_scsi_tmf_resp_work(struct vhost_work *work) else resp_code = VIRTIO_SCSI_S_FUNCTION_REJECTED; + mutex_lock(&tmf->svq->vq.mutex); vhost_scsi_send_tmf_resp(tmf->vhost, &tmf->svq->vq, tmf->in_iovs, tmf->vq_desc, &tmf->resp_iov, resp_code); + mutex_unlock(&tmf->svq->vq.mutex); + vhost_scsi_release_tmf_res(tmf); } -- 2.34.1

3 months, 4 weeks

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[PATCH] cxl/region: Balance device refcount when destroying devices

by Ma Ke

Using device_find_child() to lookup the proper device to destroy causes an unbalance in device refcount, since device_find_child() calls an implicit get_device() to increment the device's reference count before returning the pointer. cxl_port_find_switch_decoder() directly converts this pointer to a cxl_decoder and returns it without releasing the reference properly. We should call put_device() to decrement reference count. As comment of device_find_child() says, 'NOTE: you will need to drop the reference with put_device() after use'. Found by code review. Cc: stable(a)vger.kernel.org Fixes: d6879d8cfb81 ("cxl/region: Add function to find a port's switch decoder by range") Signed-off-by: Ma Ke <make24(a)iscas.ac.cn> --- drivers/cxl/core/region.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 6e5e1460068d..cae16d761261 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -3234,6 +3234,9 @@ cxl_port_find_switch_decoder(struct cxl_port *port, struct range *hpa) struct device *cxld_dev = device_find_child(&port->dev, hpa, match_decoder_by_range); + /* Drop the refcnt bumped implicitly by device_find_child */ + put_device(cxld_dev); + return cxld_dev ? to_cxl_decoder(cxld_dev) : NULL; } -- 2.25.1

3 months, 4 weeks

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FAILED: patch "[PATCH] ksmbd: fix a mount write count leak in" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 277627b431a0a6401635c416a21b2a0f77a77347 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071424-payroll-posh-4e3e@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 277627b431a0a6401635c416a21b2a0f77a77347 Mon Sep 17 00:00:00 2001 From: Al Viro <viro(a)zeniv.linux.org.uk> Date: Sun, 6 Jul 2025 02:26:45 +0100 Subject: [PATCH] ksmbd: fix a mount write count leak in ksmbd_vfs_kern_path_locked() If the call of ksmbd_vfs_lock_parent() fails, we drop the parent_path references and return an error. We need to drop the write access we just got on parent_path->mnt before we drop the mount reference - callers assume that ksmbd_vfs_kern_path_locked() returns with mount write access grabbed if and only if it has returned 0. Fixes: 864fb5d37163 ("ksmbd: fix possible deadlock in smb2_open") Signed-off-by: Al Viro <viro(a)zeniv.linux.org.uk> Acked-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c index 0f3aad12e495..d3437f6644e3 100644 --- a/fs/smb/server/vfs.c +++ b/fs/smb/server/vfs.c @@ -1282,6 +1282,7 @@ int ksmbd_vfs_kern_path_locked(struct ksmbd_work *work, char *name, err = ksmbd_vfs_lock_parent(parent_path->dentry, path->dentry); if (err) { + mnt_drop_write(parent_path->mnt); path_put(path); path_put(parent_path); }

3 months, 4 weeks

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FAILED: patch "[PATCH] smb: server: make use of rdma_destroy_qp()" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 0c2b53997e8f5e2ec9e0fbd17ac0436466b65488 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071408-overarch-ashes-8fbd@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 0c2b53997e8f5e2ec9e0fbd17ac0436466b65488 Mon Sep 17 00:00:00 2001 From: Stefan Metzmacher <metze(a)samba.org> Date: Wed, 2 Jul 2025 09:18:05 +0200 Subject: [PATCH] smb: server: make use of rdma_destroy_qp() The qp is created by rdma_create_qp() as t->cm_id->qp and t->qp is just a shortcut. rdma_destroy_qp() also calls ib_destroy_qp(cm_id->qp) internally, but it is protected by a mutex, clears the cm_id and also calls trace_cm_qp_destroy(). This should make the tracing more useful as both rdma_create_qp() and rdma_destroy_qp() are traces and it makes the code look more sane as functions from the same layer are used for the specific qp object. trace-cmd stream -e rdma_cma:cm_qp_create -e rdma_cma:cm_qp_destroy shows this now while doing a mount and unmount from a client: <...>-80 [002] 378.514182: cm_qp_create: cm.id=1 src=172.31.9.167:5445 dst=172.31.9.166:37113 tos=0 pd.id=0 qp_type=RC send_wr=867 recv_wr=255 qp_num=1 rc=0 <...>-6283 [001] 381.686172: cm_qp_destroy: cm.id=1 src=172.31.9.167:5445 dst=172.31.9.166:37113 tos=0 qp_num=1 Before we only saw the first line. Cc: Namjae Jeon <linkinjeon(a)kernel.org> Cc: Steve French <stfrench(a)microsoft.com> Cc: Sergey Senozhatsky <sergey.senozhatsky(a)gmail.com> Cc: Hyunchul Lee <hyc.lee(a)gmail.com> Cc: Tom Talpey <tom(a)talpey.com> Cc: linux-cifs(a)vger.kernel.org Fixes: 0626e6641f6b ("cifsd: add server handler for central processing and tranport layers") Signed-off-by: Stefan Metzmacher <metze(a)samba.org> Reviewed-by: Tom Talpey <tom(a)talpey.com> Acked-by: Namjae Jeon <linkinjeon(a)kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> diff --git a/fs/smb/server/transport_rdma.c b/fs/smb/server/transport_rdma.c index 64a428a06ace..c6cbe0d56e32 100644 --- a/fs/smb/server/transport_rdma.c +++ b/fs/smb/server/transport_rdma.c @@ -433,7 +433,8 @@ static void free_transport(struct smb_direct_transport *t) if (t->qp) { ib_drain_qp(t->qp); ib_mr_pool_destroy(t->qp, &t->qp->rdma_mrs); - ib_destroy_qp(t->qp); + t->qp = NULL; + rdma_destroy_qp(t->cm_id); } ksmbd_debug(RDMA, "drain the reassembly queue\n"); @@ -1940,8 +1941,8 @@ static int smb_direct_create_qpair(struct smb_direct_transport *t, return 0; err: if (t->qp) { - ib_destroy_qp(t->qp); t->qp = NULL; + rdma_destroy_qp(t->cm_id); } if (t->recv_cq) { ib_destroy_cq(t->recv_cq);

3 months, 4 weeks

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[PATCH 1/2] objtool/rust: add one more `noreturn` Rust function for Rust 1.89.0

by Miguel Ojeda

Starting with Rust 1.89.0 (expected 2025-08-07), under `CONFIG_RUST_DEBUG_ASSERTIONS=y`, `objtool` may report: rust/kernel.o: warning: objtool: _R..._6kernel4pageNtB5_4Page8read_raw() falls through to next function _R..._6kernel4pageNtB5_4Page9write_raw() (and many others) due to calls to the `noreturn` symbol: core::panicking::panic_nounwind_fmt Thus add the mangled one to the list so that `objtool` knows it is actually `noreturn`. See commit 56d680dd23c3 ("objtool/rust: list `noreturn` Rust functions") for more details. Cc: stable(a)vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Cc: Josh Poimboeuf <jpoimboe(a)kernel.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Signed-off-by: Miguel Ojeda <ojeda(a)kernel.org> --- tools/objtool/check.c | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index f23bdda737aa..3257eefc41ed 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -224,6 +224,7 @@ static bool is_rust_noreturn(const struct symbol *func) str_ends_with(func->name, "_4core9panicking14panic_explicit") || str_ends_with(func->name, "_4core9panicking14panic_nounwind") || str_ends_with(func->name, "_4core9panicking18panic_bounds_check") || + str_ends_with(func->name, "_4core9panicking18panic_nounwind_fmt") || str_ends_with(func->name, "_4core9panicking19assert_failed_inner") || str_ends_with(func->name, "_4core9panicking30panic_null_pointer_dereference") || str_ends_with(func->name, "_4core9panicking36panic_misaligned_pointer_dereference") || -- 2.50.1

3 months, 4 weeks

3
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[PATCH 2/2] rust: use `#[used(compiler)]` to fix build and `modpost` with Rust >= 1.89.0

by Miguel Ojeda

Starting with Rust 1.89.0 (expected 2025-08-07), the Rust compiler fails to build the `rusttest` target due to undefined references such as: kernel...-cgu.0:(.text....+0x116): undefined reference to `rust_helper_kunit_get_current_test' Moreover, tooling like `modpost` gets confused: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/gpu/drm/nova/nova.o ERROR: modpost: missing MODULE_LICENSE() in drivers/gpu/nova-core/nova_core.o The reason behind both issues is that the Rust compiler will now [1] treat `#[used]` as `#[used(linker)]` instead of `#[used(compiler)]` for our targets. This means that the retain section flag (`R`, `SHF_GNU_RETAIN`) will be used and that they will be marked as `unique` too, with different IDs. In turn, that means we end up with undefined references that did not get discarded in `rusttest` and that multiple `.modinfo` sections are generated, which confuse tooling like `modpost` because they only expect one. Thus start using `#[used(compiler)]` to keep the previous behavior and to be explicit about what we want. Sadly, it is an unstable feature (`used_with_arg`) [2] -- we will talk to upstream Rust about it. The good news is that it has been available for a long time (Rust >= 1.60) [3]. The changes should also be fine for previous Rust versions, since they behave the same way as before [4]. Alternatively, we could use `#[no_mangle]` or `#[export_name = ...]` since those still behave like `#[used(compiler)]`, but of course it is not really what we want to express, and it requires other changes to avoid symbol conflicts. Cc: Björn Roy Baron <bjorn3_gh(a)protonmail.com> Cc: David Wood <david(a)davidtw.co> Cc: Wesley Wiser <wwiser(a)gmail.com> Cc: stable(a)vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs). Link: https://github.com/rust-lang/rust/pull/140872 [1] Link: https://github.com/rust-lang/rust/issues/93798 [2] Link: https://github.com/rust-lang/rust/pull/91504 [3] Link: https://godbolt.org/z/sxzWTMfzW [4] Signed-off-by: Miguel Ojeda <ojeda(a)kernel.org> --- rust/Makefile | 1 + rust/kernel/firmware.rs | 2 +- rust/kernel/kunit.rs | 2 +- rust/kernel/lib.rs | 3 +++ rust/macros/module.rs | 10 +++++----- scripts/Makefile.build | 3 ++- 6 files changed, 13 insertions(+), 8 deletions(-) diff --git a/rust/Makefile b/rust/Makefile index 27dec7904c3a..115b63b7d1e3 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -194,6 +194,7 @@ quiet_cmd_rustdoc_test = RUSTDOC T $< RUST_MODFILE=test.rs \ OBJTREE=$(abspath $(objtree)) \ $(RUSTDOC) --test $(rust_common_flags) \ + -Zcrate-attr='feature(used_with_arg)' \ @$(objtree)/include/generated/rustc_cfg \ $(rustc_target_flags) $(rustdoc_test_target_flags) \ $(rustdoc_test_quiet) \ diff --git a/rust/kernel/firmware.rs b/rust/kernel/firmware.rs index 2494c96e105f..4fe621f35716 100644 --- a/rust/kernel/firmware.rs +++ b/rust/kernel/firmware.rs @@ -202,7 +202,7 @@ macro_rules! module_firmware { }; #[link_section = ".modinfo"] - #[used] + #[used(compiler)] static __MODULE_FIRMWARE: [u8; $($builder)*::create(__MODULE_FIRMWARE_PREFIX) .build_length()] = $($builder)*::create(__MODULE_FIRMWARE_PREFIX).build(); }; diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 4b8cdcb21e77..b9e65905e121 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -302,7 +302,7 @@ macro_rules! kunit_unsafe_test_suite { is_init: false, }; - #[used] + #[used(compiler)] #[allow(unused_unsafe)] #[cfg_attr(not(target_os = "macos"), link_section = ".kunit_test_suites")] static mut KUNIT_TEST_SUITE_ENTRY: *const ::kernel::bindings::kunit_suite = diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 6b4774b2b1c3..e13d6ed88fa6 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -34,6 +34,9 @@ // Expected to become stable. #![feature(arbitrary_self_types)] // +// To be determined. +#![feature(used_with_arg)] +// // `feature(derive_coerce_pointee)` is expected to become stable. Before Rust // 1.84.0, it did not exist, so enable the predecessor features. #![cfg_attr(CONFIG_RUSTC_HAS_COERCE_POINTEE, feature(derive_coerce_pointee))] diff --git a/rust/macros/module.rs b/rust/macros/module.rs index 2ddd2eeb2852..75efc6eeeafc 100644 --- a/rust/macros/module.rs +++ b/rust/macros/module.rs @@ -57,7 +57,7 @@ fn emit_base(&mut self, field: &str, content: &str, builtin: bool) { {cfg} #[doc(hidden)] #[cfg_attr(not(target_os = \"macos\"), link_section = \".modinfo\")] - #[used] + #[used(compiler)] pub static __{module}_{counter}: [u8; {length}] = *{string}; ", cfg = if builtin { @@ -249,7 +249,7 @@ mod __module_init {{ // key or a new section. For the moment, keep it simple. #[cfg(MODULE)] #[doc(hidden)] - #[used] + #[used(compiler)] static __IS_RUST_MODULE: () = (); static mut __MOD: ::core::mem::MaybeUninit<{type_}> = @@ -273,7 +273,7 @@ mod __module_init {{ #[cfg(MODULE)] #[doc(hidden)] - #[used] + #[used(compiler)] #[link_section = \".init.data\"] static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module; @@ -293,7 +293,7 @@ mod __module_init {{ #[cfg(MODULE)] #[doc(hidden)] - #[used] + #[used(compiler)] #[link_section = \".exit.data\"] static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module; @@ -303,7 +303,7 @@ mod __module_init {{ #[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))] #[doc(hidden)] #[link_section = \"{initcall_section}\"] - #[used] + #[used(compiler)] pub static __{ident}_initcall: extern \"C\" fn() -> ::kernel::ffi::c_int = __{ident}_init; diff --git a/scripts/Makefile.build b/scripts/Makefile.build index a6461ea411f7..ba71b27aa363 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -312,10 +312,11 @@ $(obj)/%.lst: $(obj)/%.c FORCE # - Stable since Rust 1.82.0: `feature(asm_const)`, `feature(raw_ref_op)`. # - Stable since Rust 1.87.0: `feature(asm_goto)`. # - Expected to become stable: `feature(arbitrary_self_types)`. +# - To be determined: `feature(used_with_arg)`. # # Please see https://github.com/Rust-for-Linux/linux/issues/2 for details on # the unstable features in use. -rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,lint_reasons,raw_ref_op +rust_allowed_features := asm_const,asm_goto,arbitrary_self_types,lint_reasons,raw_ref_op,used_with_arg # `--out-dir` is required to avoid temporaries being created by `rustc` in the # current working directory, which may be not accessible in the out-of-tree -- 2.50.1

3 months, 4 weeks

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[PATCH] LoongArch: Make relocate_new_kernel_size be a .quad value

by Huacai Chen

Now relocate_new_kernel_size is a .long value, which means 32bit, so its high 32bit is undefined. This causes memcpy((void *)reboot_code_buffer, relocate_new_kernel, relocate_new_kernel_size) in machine_kexec_prepare() access out of range memories in some cases, and then end up with an ADE exception. So make relocate_new_kernel_size be a .quad value, which means 64bit, to avoid such errors. Cc: stable(a)vger.kernel.org Signed-off-by: Huacai Chen <chenhuacai(a)loongson.cn> --- arch/loongarch/kernel/relocate_kernel.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/loongarch/kernel/relocate_kernel.S b/arch/loongarch/kernel/relocate_kernel.S index 84e6de2fd973..8b5140ac9ea1 100644 --- a/arch/loongarch/kernel/relocate_kernel.S +++ b/arch/loongarch/kernel/relocate_kernel.S @@ -109,4 +109,4 @@ SYM_CODE_END(kexec_smp_wait) relocate_new_kernel_end: .section ".data" -SYM_DATA(relocate_new_kernel_size, .long relocate_new_kernel_end - relocate_new_kernel) +SYM_DATA(relocate_new_kernel_size, .quad relocate_new_kernel_end - relocate_new_kernel) -- 2.47.1

3 months, 4 weeks

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FAILED: patch "[PATCH] kasan: remove kasan_find_vm_area() to prevent possible" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 6ee9b3d84775944fb8c8a447961cd01274ac671c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071348-swizzle-utter-2496@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 6ee9b3d84775944fb8c8a447961cd01274ac671c Mon Sep 17 00:00:00 2001 From: Yeoreum Yun <yeoreum.yun(a)arm.com> Date: Thu, 3 Jul 2025 19:10:18 +0100 Subject: [PATCH] kasan: remove kasan_find_vm_area() to prevent possible deadlock find_vm_area() couldn't be called in atomic_context. If find_vm_area() is called to reports vm area information, kasan can trigger deadlock like: CPU0 CPU1 vmalloc(); alloc_vmap_area(); spin_lock(&vn->busy.lock) spin_lock_bh(&some_lock); <interrupt occurs> <in softirq> spin_lock(&some_lock); <access invalid address> kasan_report(); print_report(); print_address_description(); kasan_find_vm_area(); find_vm_area(); spin_lock(&vn->busy.lock) // deadlock! To prevent possible deadlock while kasan reports, remove kasan_find_vm_area(). Link: https://lkml.kernel.org/r/20250703181018.580833-1-yeoreum.yun@arm.com Fixes: c056a364e954 ("kasan: print virtual mapping info in reports") Signed-off-by: Yeoreum Yun <yeoreum.yun(a)arm.com> Reported-by: Yunseong Kim <ysk(a)kzalloc.com> Reviewed-by: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Byungchul Park <byungchul(a)sk.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de> Cc: Steven Rostedt <rostedt(a)goodmis.org> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 8357e1a33699..b0877035491f 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -370,36 +370,6 @@ static inline bool init_task_stack_addr(const void *addr) sizeof(init_thread_union.stack)); } -/* - * This function is invoked with report_lock (a raw_spinlock) held. A - * PREEMPT_RT kernel cannot call find_vm_area() as it will acquire a sleeping - * rt_spinlock. - * - * For !RT kernel, the PROVE_RAW_LOCK_NESTING config option will print a - * lockdep warning for this raw_spinlock -> spinlock dependency. This config - * option is enabled by default to ensure better test coverage to expose this - * kind of RT kernel problem. This lockdep splat, however, can be suppressed - * by using DEFINE_WAIT_OVERRIDE_MAP() if it serves a useful purpose and the - * invalid PREEMPT_RT case has been taken care of. - */ -static inline struct vm_struct *kasan_find_vm_area(void *addr) -{ - static DEFINE_WAIT_OVERRIDE_MAP(vmalloc_map, LD_WAIT_SLEEP); - struct vm_struct *va; - - if (IS_ENABLED(CONFIG_PREEMPT_RT)) - return NULL; - - /* - * Suppress lockdep warning and fetch vmalloc area of the - * offending address. - */ - lock_map_acquire_try(&vmalloc_map); - va = find_vm_area(addr); - lock_map_release(&vmalloc_map); - return va; -} - static void print_address_description(void *addr, u8 tag, struct kasan_report_info *info) { @@ -429,19 +399,8 @@ static void print_address_description(void *addr, u8 tag, } if (is_vmalloc_addr(addr)) { - struct vm_struct *va = kasan_find_vm_area(addr); - - if (va) { - pr_err("The buggy address belongs to the virtual mapping at\n" - " [%px, %px) created by:\n" - " %pS\n", - va->addr, va->addr + va->size, va->caller); - pr_err("\n"); - - page = vmalloc_to_page(addr); - } else { - pr_err("The buggy address %px belongs to a vmalloc virtual mapping\n", addr); - } + pr_err("The buggy address %px belongs to a vmalloc virtual mapping\n", addr); + page = vmalloc_to_page(addr); } if (page) {

3 months, 4 weeks

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[PATCH 6.12.y 1/1] kasan: remove kasan_find_vm_area() to prevent possible deadlock

by Yeoreum Yun

find_vm_area() couldn't be called in atomic_context. If find_vm_area() is called to reports vm area information, kasan can trigger deadlock like: CPU0 CPU1 vmalloc(); alloc_vmap_area(); spin_lock(&vn->busy.lock) spin_lock_bh(&some_lock); <interrupt occurs> <in softirq> spin_lock(&some_lock); <access invalid address> kasan_report(); print_report(); print_address_description(); kasan_find_vm_area(); find_vm_area(); spin_lock(&vn->busy.lock) // deadlock! To prevent possible deadlock while kasan reports, remove kasan_find_vm_area(). Link: https://lkml.kernel.org/r/20250703181018.580833-1-yeoreum.yun@arm.com Fixes: c056a364e954 ("kasan: print virtual mapping info in reports") Signed-off-by: Yeoreum Yun <yeoreum.yun(a)arm.com> Reported-by: Yunseong Kim <ysk(a)kzalloc.com> Reviewed-by: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Byungchul Park <byungchul(a)sk.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de> Cc: Steven Rostedt <rostedt(a)goodmis.org> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> (cherry picked from commit 6ee9b3d84775944fb8c8a447961cd01274ac671c) --- mm/kasan/report.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index c7c0083203cb..5675d6a412ef 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -398,17 +398,8 @@ static void print_address_description(void *addr, u8 tag, } if (is_vmalloc_addr(addr)) { - struct vm_struct *va = find_vm_area(addr); - - if (va) { - pr_err("The buggy address belongs to the virtual mapping at\n" - " [%px, %px) created by:\n" - " %pS\n", - va->addr, va->addr + va->size, va->caller); - pr_err("\n"); - - page = vmalloc_to_page(addr); - } + pr_err("The buggy address %px belongs to a vmalloc virtual mapping\n", addr); + page = vmalloc_to_page(addr); } if (page) { -- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

3 months, 4 weeks

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FAILED: patch "[PATCH] kasan: remove kasan_find_vm_area() to prevent possible" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 6ee9b3d84775944fb8c8a447961cd01274ac671c # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025071347-pregnant-dismount-40e9@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 6ee9b3d84775944fb8c8a447961cd01274ac671c Mon Sep 17 00:00:00 2001 From: Yeoreum Yun <yeoreum.yun(a)arm.com> Date: Thu, 3 Jul 2025 19:10:18 +0100 Subject: [PATCH] kasan: remove kasan_find_vm_area() to prevent possible deadlock find_vm_area() couldn't be called in atomic_context. If find_vm_area() is called to reports vm area information, kasan can trigger deadlock like: CPU0 CPU1 vmalloc(); alloc_vmap_area(); spin_lock(&vn->busy.lock) spin_lock_bh(&some_lock); <interrupt occurs> <in softirq> spin_lock(&some_lock); <access invalid address> kasan_report(); print_report(); print_address_description(); kasan_find_vm_area(); find_vm_area(); spin_lock(&vn->busy.lock) // deadlock! To prevent possible deadlock while kasan reports, remove kasan_find_vm_area(). Link: https://lkml.kernel.org/r/20250703181018.580833-1-yeoreum.yun@arm.com Fixes: c056a364e954 ("kasan: print virtual mapping info in reports") Signed-off-by: Yeoreum Yun <yeoreum.yun(a)arm.com> Reported-by: Yunseong Kim <ysk(a)kzalloc.com> Reviewed-by: Andrey Ryabinin <ryabinin.a.a(a)gmail.com> Cc: Alexander Potapenko <glider(a)google.com> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Byungchul Park <byungchul(a)sk.com> Cc: Dmitriy Vyukov <dvyukov(a)google.com> Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de> Cc: Steven Rostedt <rostedt(a)goodmis.org> Cc: Vincenzo Frascino <vincenzo.frascino(a)arm.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 8357e1a33699..b0877035491f 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -370,36 +370,6 @@ static inline bool init_task_stack_addr(const void *addr) sizeof(init_thread_union.stack)); } -/* - * This function is invoked with report_lock (a raw_spinlock) held. A - * PREEMPT_RT kernel cannot call find_vm_area() as it will acquire a sleeping - * rt_spinlock. - * - * For !RT kernel, the PROVE_RAW_LOCK_NESTING config option will print a - * lockdep warning for this raw_spinlock -> spinlock dependency. This config - * option is enabled by default to ensure better test coverage to expose this - * kind of RT kernel problem. This lockdep splat, however, can be suppressed - * by using DEFINE_WAIT_OVERRIDE_MAP() if it serves a useful purpose and the - * invalid PREEMPT_RT case has been taken care of. - */ -static inline struct vm_struct *kasan_find_vm_area(void *addr) -{ - static DEFINE_WAIT_OVERRIDE_MAP(vmalloc_map, LD_WAIT_SLEEP); - struct vm_struct *va; - - if (IS_ENABLED(CONFIG_PREEMPT_RT)) - return NULL; - - /* - * Suppress lockdep warning and fetch vmalloc area of the - * offending address. - */ - lock_map_acquire_try(&vmalloc_map); - va = find_vm_area(addr); - lock_map_release(&vmalloc_map); - return va; -} - static void print_address_description(void *addr, u8 tag, struct kasan_report_info *info) { @@ -429,19 +399,8 @@ static void print_address_description(void *addr, u8 tag, } if (is_vmalloc_addr(addr)) { - struct vm_struct *va = kasan_find_vm_area(addr); - - if (va) { - pr_err("The buggy address belongs to the virtual mapping at\n" - " [%px, %px) created by:\n" - " %pS\n", - va->addr, va->addr + va->size, va->caller); - pr_err("\n"); - - page = vmalloc_to_page(addr); - } else { - pr_err("The buggy address %px belongs to a vmalloc virtual mapping\n", addr); - } + pr_err("The buggy address %px belongs to a vmalloc virtual mapping\n", addr); + page = vmalloc_to_page(addr); } if (page) {

3 months, 4 weeks

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