April 2025 - Linux-stable-mirror

+ lib-iov_iter-fix-to-increase-non-slab-folio-refcount.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: lib/iov_iter: fix to increase non slab folio refcount has been added to the -mm mm-hotfixes-unstable branch. Its filename is lib-iov_iter-fix-to-increase-non-slab-folio-refcount.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche… This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Sheng Yong <shengyong1(a)xiaomi.com> Subject: lib/iov_iter: fix to increase non slab folio refcount Date: Tue, 1 Apr 2025 22:47:12 +0800 When testing EROFS file-backed mount over v9fs on qemu, I encountered a folio UAF issue. The page sanity check reports the following call trace. The root cause is that pages in bvec are coalesced across a folio bounary. The refcount of all non-slab folios should be increased to ensure p9_releas_pages can put them correctly. BUG: Bad page state in process md5sum pfn:18300 page: refcount:0 mapcount:0 mapping:00000000d5ad8e4e index:0x60 pfn:0x18300 head: order:0 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 aops:z_erofs_aops ino:30b0f dentry name(?):"GoogleExtServicesCn.apk" flags: 0x100000000000041(locked|head|node=0|zone=1) raw: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0 raw: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000 head: 0100000000000041 dead000000000100 dead000000000122 ffff888014b13bd0 head: 0000000000000060 0000000000000020 00000000ffffffff 0000000000000000 head: 0100000000000000 0000000000000000 ffffffffffffffff 0000000000000000 head: 0000000000000010 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set Call Trace: dump_stack_lvl+0x53/0x70 bad_page+0xd4/0x220 __free_pages_ok+0x76d/0xf30 __folio_put+0x230/0x320 p9_release_pages+0x179/0x1f0 p9_virtio_zc_request+0xa2a/0x1230 p9_client_zc_rpc.constprop.0+0x247/0x700 p9_client_read_once+0x34d/0x810 p9_client_read+0xf3/0x150 v9fs_issue_read+0x111/0x360 netfs_unbuffered_read_iter_locked+0x927/0x1390 netfs_unbuffered_read_iter+0xa2/0xe0 vfs_iocb_iter_read+0x2c7/0x460 erofs_fileio_rq_submit+0x46b/0x5b0 z_erofs_runqueue+0x1203/0x21e0 z_erofs_readahead+0x579/0x8b0 read_pages+0x19f/0xa70 page_cache_ra_order+0x4ad/0xb80 filemap_readahead.isra.0+0xe7/0x150 filemap_get_pages+0x7aa/0x1890 filemap_read+0x320/0xc80 vfs_read+0x6c6/0xa30 ksys_read+0xf9/0x1c0 do_syscall_64+0x9e/0x1a0 entry_SYSCALL_64_after_hwframe+0x71/0x79 Link: https://lkml.kernel.org/r/20250401144712.1377719-1-shengyong1@xiaomi.com Fixes: b9c0e49abfca ("mm: decline to manipulate the refcount on a slab page") Signed-off-by: Sheng Yong <shengyong1(a)xiaomi.com> Reviewed-by: Matthew Wilcox (Oracle) <willy(a)infradead.org> Acked-by: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- lib/iov_iter.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/iov_iter.c~lib-iov_iter-fix-to-increase-non-slab-folio-refcount +++ a/lib/iov_iter.c @@ -1191,7 +1191,7 @@ static ssize_t __iov_iter_get_pages_allo return -ENOMEM; p = *pages; for (int k = 0; k < n; k++) { - struct folio *folio = page_folio(page); + struct folio *folio = page_folio(page + k); p[k] = page + k; if (!folio_test_slab(folio)) folio_get(folio); _ Patches currently in -mm which might be from shengyong1(a)xiaomi.com are lib-iov_iter-fix-to-increase-non-slab-folio-refcount.patch

3 weeks, 1 day

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[for-linus][PATCH 4/4] ring-buffer: Use flush_kernel_vmap_range() over flush_dcache_folio()

by Steven Rostedt

From: Steven Rostedt <rostedt(a)goodmis.org> Some architectures do not have data cache coherency between user and kernel space. For these architectures, the cache needs to be flushed on both the kernel and user addresses so that user space can see the updates the kernel has made. Instead of using flush_dcache_folio() and playing with virt_to_folio() within the call to that function, use flush_kernel_vmap_range() which takes the virtual address and does the work for those architectures that need it. This also fixes a bug where the flush of the reader page only flushed one page. If the sub-buffer order is 1 or more, where the sub-buffer size would be greater than a page, it would miss the rest of the sub-buffer content, as the "reader page" is not just a page, but the size of a sub-buffer. Link: https://lore.kernel.org/all/CAG48ez3w0my4Rwttbc5tEbNsme6tc0mrSN95thjXUFaJ3a… Cc: stable(a)vger.kernel.org Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Vincent Donnefort <vdonnefort(a)google.com> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Mike Rapoport <rppt(a)kernel.org> Link: https://lore.kernel.org/20250402144953.920792197@goodmis.org Fixes: 117c39200d9d7 ("ring-buffer: Introducing ring-buffer mapping functions"); Suggested-by: Jann Horn <jannh(a)google.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/ring_buffer.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index f25966b3a1fc..d4b0f7b55cce 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -6016,7 +6016,7 @@ static void rb_update_meta_page(struct ring_buffer_per_cpu *cpu_buffer) meta->read = cpu_buffer->read; /* Some archs do not have data cache coherency between kernel and user-space */ - flush_dcache_folio(virt_to_folio(cpu_buffer->meta_page)); + flush_kernel_vmap_range(cpu_buffer->meta_page, PAGE_SIZE); } static void @@ -7319,7 +7319,8 @@ int ring_buffer_map_get_reader(struct trace_buffer *buffer, int cpu) out: /* Some archs do not have data cache coherency between kernel and user-space */ - flush_dcache_folio(virt_to_folio(cpu_buffer->reader_page->page)); + flush_kernel_vmap_range(cpu_buffer->reader_page->page, + buffer->subbuf_size + BUF_PAGE_HDR_SIZE); rb_update_meta_page(cpu_buffer); -- 2.47.2

3 weeks, 1 day

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[PATCH v4] usb: dwc3: gadget: check that event count does not exceed event buffer length

by Frode Isaksen

From: Frode Isaksen <frode(a)meta.com> The event count is read from register DWC3_GEVNTCOUNT. There is a check for the count being zero, but not for exceeding the event buffer length. Check that event count does not exceed event buffer length, avoiding an out-of-bounds access when memcpy'ing the event. Crash log: Unable to handle kernel paging request at virtual address ffffffc0129be000 pc : __memcpy+0x114/0x180 lr : dwc3_check_event_buf+0xec/0x348 x3 : 0000000000000030 x2 : 000000000000dfc4 x1 : ffffffc0129be000 x0 : ffffff87aad60080 Call trace: __memcpy+0x114/0x180 dwc3_interrupt+0x24/0x34 Signed-off-by: Frode Isaksen <frode(a)meta.com> Fixes: ebbb2d59398f ("usb: dwc3: gadget: use evt->cache for processing events") Cc: stable(a)vger.kernel.org --- v1 -> v2: Added Fixes and Cc tag. v2 -> v3: Added error log v3 -> v4: Rate limit error log drivers/usb/dwc3/gadget.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 89a4dc8ebf94..b75b4c5ca7fc 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4564,6 +4564,12 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt) if (!count) return IRQ_NONE; + if (count > evt->length) { + dev_err_ratelimited(dwc->dev, "invalid count(%u) > evt->length(%u)\n", + count, evt->length); + return IRQ_NONE; + } + evt->count = count; evt->flags |= DWC3_EVENT_PENDING; -- 2.49.0

3 weeks, 1 day

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[PATCH v2] usb: dwc3: gadget: check that event count does not exceed event buffer length

by Frode Isaksen

From: Frode Isaksen <frode(a)meta.com> The event count is read from register DWC3_GEVNTCOUNT. There is a check for the count being zero, but not for exceeding the event buffer length. Check that event count does not exceed event buffer length, avoiding an out-of-bounds access when memcpy'ing the event. Crash log: Unable to handle kernel paging request at virtual address ffffffc0129be000 pc : __memcpy+0x114/0x180 lr : dwc3_check_event_buf+0xec/0x348 x3 : 0000000000000030 x2 : 000000000000dfc4 x1 : ffffffc0129be000 x0 : ffffff87aad60080 Call trace: __memcpy+0x114/0x180 dwc3_interrupt+0x24/0x34 Signed-off-by: Frode Isaksen <frode(a)meta.com> Fixes: ebbb2d59398f ("usb: dwc3: gadget: use evt->cache for processing events") Cc: stable(a)vger.kernel.org --- v1 -> v2: Added Fixes and Cc tag. This bug was discovered, tested and fixed (no more crashes seen) on Meta Quest 3 device. Also tested on T.I. AM62x board. drivers/usb/dwc3/gadget.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 63fef4a1a498..548e112167f3 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4564,7 +4564,7 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt) count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0)); count &= DWC3_GEVNTCOUNT_MASK; - if (!count) + if (!count || count > evt->length) return IRQ_NONE; evt->count = count; -- 2.48.1

3 weeks, 1 day

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[PATCH 5.15.y] smb: client: fix use-after-free bug in cifs_debug_data_proc_show()

by Xiangyu Chen

From: Paulo Alcantara <pc(a)manguebit.com> commit d328c09ee9f15ee5a26431f5aad7c9239fa85e62 upstream. Skip SMB sessions that are being teared down (e.g. @ses->ses_status == SES_EXITING) in cifs_debug_data_proc_show() to avoid use-after-free in @ses. This fixes the following GPF when reading from /proc/fs/cifs/DebugData while mounting and umounting [ 816.251274] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6d81: 0000 [#1] PREEMPT SMP NOPTI ... [ 816.260138] Call Trace: [ 816.260329] <TASK> [ 816.260499] ? die_addr+0x36/0x90 [ 816.260762] ? exc_general_protection+0x1b3/0x410 [ 816.261126] ? asm_exc_general_protection+0x26/0x30 [ 816.261502] ? cifs_debug_tcon+0xbd/0x240 [cifs] [ 816.261878] ? cifs_debug_tcon+0xab/0x240 [cifs] [ 816.262249] cifs_debug_data_proc_show+0x516/0xdb0 [cifs] [ 816.262689] ? seq_read_iter+0x379/0x470 [ 816.262995] seq_read_iter+0x118/0x470 [ 816.263291] proc_reg_read_iter+0x53/0x90 [ 816.263596] ? srso_alias_return_thunk+0x5/0x7f [ 816.263945] vfs_read+0x201/0x350 [ 816.264211] ksys_read+0x75/0x100 [ 816.264472] do_syscall_64+0x3f/0x90 [ 816.264750] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 816.265135] RIP: 0033:0x7fd5e669d381 Cc: stable(a)vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> [ This patch removed lock/unlock operation due to ses_lock is not present in v5.15 and not ported yet. ses->status is protected by a global lock, cifs_tcp_ses_lock, in v5.15. ] Signed-off-by: Xiangyu Chen <xiangyu.chen(a)windriver.com> Signed-off-by: He Zhe <zhe.he(a)windriver.com> --- Verified build test. --- fs/cifs/cifs_debug.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c index e7501533c2ec..c90f51c12fb0 100644 --- a/fs/cifs/cifs_debug.c +++ b/fs/cifs/cifs_debug.c @@ -380,6 +380,8 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v) list_for_each(tmp2, &server->smb_ses_list) { ses = list_entry(tmp2, struct cifs_ses, smb_ses_list); + if (ses->status == CifsExiting) + continue; i++; if ((ses->serverDomain == NULL) || (ses->serverOS == NULL) || -- 2.43.0

3 weeks, 1 day

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[PATCH 5.10.y] smb: client: fix use-after-free bug in cifs_debug_data_proc_show()

by Xiangyu Chen

From: Paulo Alcantara <pc(a)manguebit.com> commit d328c09ee9f15ee5a26431f5aad7c9239fa85e62 upstream. Skip SMB sessions that are being teared down (e.g. @ses->ses_status == SES_EXITING) in cifs_debug_data_proc_show() to avoid use-after-free in @ses. This fixes the following GPF when reading from /proc/fs/cifs/DebugData while mounting and umounting [ 816.251274] general protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6d81: 0000 [#1] PREEMPT SMP NOPTI ... [ 816.260138] Call Trace: [ 816.260329] <TASK> [ 816.260499] ? die_addr+0x36/0x90 [ 816.260762] ? exc_general_protection+0x1b3/0x410 [ 816.261126] ? asm_exc_general_protection+0x26/0x30 [ 816.261502] ? cifs_debug_tcon+0xbd/0x240 [cifs] [ 816.261878] ? cifs_debug_tcon+0xab/0x240 [cifs] [ 816.262249] cifs_debug_data_proc_show+0x516/0xdb0 [cifs] [ 816.262689] ? seq_read_iter+0x379/0x470 [ 816.262995] seq_read_iter+0x118/0x470 [ 816.263291] proc_reg_read_iter+0x53/0x90 [ 816.263596] ? srso_alias_return_thunk+0x5/0x7f [ 816.263945] vfs_read+0x201/0x350 [ 816.264211] ksys_read+0x75/0x100 [ 816.264472] do_syscall_64+0x3f/0x90 [ 816.264750] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 816.265135] RIP: 0033:0x7fd5e669d381 Cc: stable(a)vger.kernel.org Signed-off-by: Paulo Alcantara (SUSE) <pc(a)manguebit.com> Signed-off-by: Steve French <stfrench(a)microsoft.com> [ This patch removed lock/unlock operation due to ses_lock is not present in v5.10 and not ported yet. ses->status is protected by a global lock, cifs_tcp_ses_lock, in v5.10. ] Signed-off-by: Xiangyu Chen <xiangyu.chen(a)windriver.com> Signed-off-by: He Zhe <zhe.he(a)windriver.com> --- Verified the build test. --- fs/cifs/cifs_debug.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c index 53588d7517b4..5ec4788341c2 100644 --- a/fs/cifs/cifs_debug.c +++ b/fs/cifs/cifs_debug.c @@ -356,6 +356,8 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v) list_for_each(tmp2, &server->smb_ses_list) { ses = list_entry(tmp2, struct cifs_ses, smb_ses_list); + if (ses->status == CifsExiting) + continue; if ((ses->serverDomain == NULL) || (ses->serverOS == NULL) || (ses->serverNOS == NULL)) { -- 2.43.0

3 weeks, 1 day

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[PATCH 5.10.y] i2c: dev: check return value when calling dev_set_name()

by Feng Liu

From: Andy Shevchenko <andriy.shevchenko(a)linux.intel.com> [ Upstream commit 993eb48fa199b5f476df8204e652eff63dd19361 ] If dev_set_name() fails, the dev_name() is null, check the return value of dev_set_name() to avoid the null-ptr-deref. Fixes: 1413ef638aba ("i2c: dev: Fix the race between the release of i2c_dev and cdev") Signed-off-by: Andy Shevchenko <andriy.shevchenko(a)linux.intel.com> Signed-off-by: Wolfram Sang <wsa(a)kernel.org> Signed-off-by: Feng Liu <Feng.Liu3(a)windriver.com> Signed-off-by: He Zhe <Zhe.He(a)windriver.com> --- Verified the build test. --- drivers/i2c/i2c-dev.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index dafad891998e..f0bd4ae19df6 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -669,17 +669,22 @@ static int i2cdev_attach_adapter(struct device *dev, void *dummy) i2c_dev->dev.class = i2c_dev_class; i2c_dev->dev.parent = &adap->dev; i2c_dev->dev.release = i2cdev_dev_release; - dev_set_name(&i2c_dev->dev, "i2c-%d", adap->nr); + + res = dev_set_name(&i2c_dev->dev, "i2c-%d", adap->nr); + if (res) + goto err_put_i2c_dev; res = cdev_device_add(&i2c_dev->cdev, &i2c_dev->dev); - if (res) { - put_i2c_dev(i2c_dev, false); - return res; - } + if (res) + goto err_put_i2c_dev; pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", adap->name, adap->nr); return 0; + +err_put_i2c_dev: + put_i2c_dev(i2c_dev, false); + return res; } static int i2cdev_detach_adapter(struct device *dev, void *dummy) -- 2.34.1

3 weeks, 1 day

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[PATCH 5.10.y] bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers

by Cliff Liu

From: Hou Tao <houtao1(a)huawei.com> [ Upstream commit 169410eba271afc9f0fb476d996795aa26770c6d ] These three bpf_map_{lookup,update,delete}_elem() helpers are also available for sleepable bpf program, so add the corresponding lock assertion for sleepable bpf program, otherwise the following warning will be reported when a sleepable bpf program manipulates bpf map under interpreter mode (aka bpf_jit_enable=0): WARNING: CPU: 3 PID: 4985 at kernel/bpf/helpers.c:40 ...... CPU: 3 PID: 4985 Comm: test_progs Not tainted 6.6.0+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...... RIP: 0010:bpf_map_lookup_elem+0x54/0x60 ...... Call Trace: <TASK> ? __warn+0xa5/0x240 ? bpf_map_lookup_elem+0x54/0x60 ? report_bug+0x1ba/0x1f0 ? handle_bug+0x40/0x80 ? exc_invalid_op+0x18/0x50 ? asm_exc_invalid_op+0x1b/0x20 ? __pfx_bpf_map_lookup_elem+0x10/0x10 ? rcu_lockdep_current_cpu_online+0x65/0xb0 ? rcu_is_watching+0x23/0x50 ? bpf_map_lookup_elem+0x54/0x60 ? __pfx_bpf_map_lookup_elem+0x10/0x10 ___bpf_prog_run+0x513/0x3b70 __bpf_prog_run32+0x9d/0xd0 ? __bpf_prog_enter_sleepable_recur+0xad/0x120 ? __bpf_prog_enter_sleepable_recur+0x3e/0x120 bpf_trampoline_6442580665+0x4d/0x1000 __x64_sys_getpgid+0x5/0x30 ? do_syscall_64+0x36/0xb0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 </TASK> Signed-off-by: Hou Tao <houtao1(a)huawei.com> Link: https://lore.kernel.org/r/20231204140425.1480317-2-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> [Minor conflict resolved due to code context change.] Signed-off-by: Cliff Liu <donghua.liu(a)windriver.com> Signed-off-by: He Zhe <Zhe.He(a)windriver.com> --- Verified the build test. --- kernel/bpf/helpers.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 31e3a5482156..238a51daefa4 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -3,6 +3,7 @@ */ #include <linux/bpf.h> #include <linux/rcupdate.h> +#include <linux/rcupdate_trace.h> #include <linux/random.h> #include <linux/smp.h> #include <linux/topology.h> @@ -24,12 +25,12 @@ * * Different map implementations will rely on rcu in map methods * lookup/update/delete, therefore eBPF programs must run under rcu lock - * if program is allowed to access maps, so check rcu_read_lock_held in - * all three functions. + * if program is allowed to access maps, so check rcu_read_lock_held() or + * rcu_read_lock_trace_held() in all three functions. */ BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key) { - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); return (unsigned long) map->ops->map_lookup_elem(map, key); } @@ -45,7 +46,7 @@ const struct bpf_func_proto bpf_map_lookup_elem_proto = { BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key, void *, value, u64, flags) { - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); return map->ops->map_update_elem(map, key, value, flags); } @@ -62,7 +63,7 @@ const struct bpf_func_proto bpf_map_update_elem_proto = { BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key) { - WARN_ON_ONCE(!rcu_read_lock_held()); + WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_trace_held()); return map->ops->map_delete_elem(map, key); } -- 2.34.1

3 weeks, 1 day

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[PATCH v2 2/2] Revert "smb: client: fix TCP timers deadlock after rmmod"

by Kuniyuki Iwashima

This reverts commit e9f2517a3e18a54a3943c098d2226b245d488801. Commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock after rmmod") is intended to fix a null-ptr-deref in LOCKDEP, which is mentioned as CVE-2024-54680, but is actually did not fix anything; The issue can be reproduced on top of it. [0] Also, it reverted the change by commit ef7134c7fc48 ("smb: client: Fix use-after-free of network namespace.") and introduced a real issue by reviving the kernel TCP socket. When a reconnect happens for a CIFS connection, the socket state transitions to FIN_WAIT_1. Then, inet_csk_clear_xmit_timers_sync() in tcp_close() stops all timers for the socket. If an incoming FIN packet is lost, the socket will stay at FIN_WAIT_1 forever, and such sockets could be leaked up to net.ipv4.tcp_max_orphans. Usually, FIN can be retransmitted by the peer, but if the peer aborts the connection, the issue comes into reality. I warned about this privately by pointing out the exact report [1], but the bogus fix was finally merged. So, we should not stop the timers to finally kill the connection on our side in that case, meaning we must not use a kernel socket for TCP whose sk->sk_net_refcnt is 0. The kernel socket does not have a reference to its netns to make it possible to tear down netns without cleaning up every resource in it. For example, tunnel devices use a UDP socket internally, but we can destroy netns without removing such devices and let it complete during exit. Otherwise, netns would be leaked when the last application died. However, this is problematic for TCP sockets because TCP has timers to close the connection gracefully even after the socket is close()d. The lifetime of the socket and its netns is different from the lifetime of the underlying connection. If the socket user does not maintain the netns lifetime, the timer could be fired after the socket is close()d and its netns is freed up, resulting in use-after-free. Actually, we have seen so many similar issues and converted such sockets to have a reference to netns. That's why I converted the CIFS client socket to have a reference to netns (sk->sk_net_refcnt == 1), which is somehow mentioned as out-of-scope of CIFS and technically wrong in e9f2517a3e18, but **is in-scope and right fix**. Regarding the LOCKDEP issue, we can prevent the module unload by bumping the module refcount when switching the LOCKDDEP key in sock_lock_init_class_and_name(). [2] For a while, let's revert the bogus fix. Note that now we can use sk_net_refcnt_upgrade() for the socket conversion, but I'll do so later separately to make backport easy. Link: https://lore.kernel.org/all/20250402020807.28583-1-kuniyu@amazon.com/ #[0] Link: https://lore.kernel.org/netdev/c08bd5378da647a2a4c16698125d180a@huawei.com/ #[1] Link: https://lore.kernel.org/lkml/20250402005841.19846-1-kuniyu@amazon.com/ #[2] Fixes: e9f2517a3e18 ("smb: client: fix TCP timers deadlock after rmmod") Signed-off-by: Kuniyuki Iwashima <kuniyu(a)amazon.com> Cc: stable(a)vger.kernel.org --- fs/smb/client/connect.c | 36 ++++++++++-------------------------- 1 file changed, 10 insertions(+), 26 deletions(-) diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index 137a611c5ab0..989d8808260b 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -1073,13 +1073,9 @@ clean_demultiplex_info(struct TCP_Server_Info *server) msleep(125); if (cifs_rdma_enabled(server)) smbd_destroy(server); - if (server->ssocket) { sock_release(server->ssocket); server->ssocket = NULL; - - /* Release netns reference for the socket. */ - put_net(cifs_net_ns(server)); } if (!list_empty(&server->pending_mid_q)) { @@ -1127,7 +1123,6 @@ clean_demultiplex_info(struct TCP_Server_Info *server) */ } - /* Release netns reference for this server. */ put_net(cifs_net_ns(server)); kfree(server->leaf_fullpath); kfree(server->hostname); @@ -1773,8 +1768,6 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx, tcp_ses->ops = ctx->ops; tcp_ses->vals = ctx->vals; - - /* Grab netns reference for this server. */ cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns)); tcp_ses->sign = ctx->sign; @@ -1902,7 +1895,6 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx, out_err_crypto_release: cifs_crypto_secmech_release(tcp_ses); - /* Release netns reference for this server. */ put_net(cifs_net_ns(tcp_ses)); out_err: @@ -1911,10 +1903,8 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx, cifs_put_tcp_session(tcp_ses->primary_server, false); kfree(tcp_ses->hostname); kfree(tcp_ses->leaf_fullpath); - if (tcp_ses->ssocket) { + if (tcp_ses->ssocket) sock_release(tcp_ses->ssocket); - put_net(cifs_net_ns(tcp_ses)); - } kfree(tcp_ses); } return ERR_PTR(rc); @@ -3356,20 +3346,20 @@ generic_ip_connect(struct TCP_Server_Info *server) socket = server->ssocket; } else { struct net *net = cifs_net_ns(server); + struct sock *sk; - rc = sock_create_kern(net, sfamily, SOCK_STREAM, IPPROTO_TCP, &server->ssocket); + rc = __sock_create(net, sfamily, SOCK_STREAM, + IPPROTO_TCP, &server->ssocket, 1); if (rc < 0) { cifs_server_dbg(VFS, "Error %d creating socket\n", rc); return rc; } - /* - * Grab netns reference for the socket. - * - * It'll be released here, on error, or in clean_demultiplex_info() upon server - * teardown. - */ - get_net(net); + sk = server->ssocket->sk; + __netns_tracker_free(net, &sk->ns_tracker, false); + sk->sk_net_refcnt = 1; + get_net_track(net, &sk->ns_tracker, GFP_KERNEL); + sock_inuse_add(net, 1); /* BB other socket options to set KEEPALIVE, NODELAY? */ cifs_dbg(FYI, "Socket created\n"); @@ -3383,10 +3373,8 @@ generic_ip_connect(struct TCP_Server_Info *server) } rc = bind_socket(server); - if (rc < 0) { - put_net(cifs_net_ns(server)); + if (rc < 0) return rc; - } /* * Eventually check for other socket options to change from @@ -3423,7 +3411,6 @@ generic_ip_connect(struct TCP_Server_Info *server) if (rc < 0) { cifs_dbg(FYI, "Error %d connecting to server\n", rc); trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc); - put_net(cifs_net_ns(server)); sock_release(socket); server->ssocket = NULL; return rc; @@ -3441,9 +3428,6 @@ generic_ip_connect(struct TCP_Server_Info *server) (server->rfc1001_sessinit == -1 && sport == htons(RFC1001_PORT))) rc = ip_rfc1001_connect(server); - if (rc < 0) - put_net(cifs_net_ns(server)); - return rc; } -- 2.48.1

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[PATCH v2 1/2] Revert "smb: client: Fix netns refcount imbalance causing leaks and use-after-free"

by Kuniyuki Iwashima

This reverts commit 4e7f1644f2ac6d01dc584f6301c3b1d5aac4eaef. The commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock after rmmod") is not only a bogus fix for LOCKDEP null-ptr-deref but also introduces a real issue, TCP sockets leak, which will be explained in detail in the next revert. Also, CNA assigned CVE-2024-54680 to it but is rejecting it. [0] Thus, we are reverting the commit and its follow-up commit 4e7f1644f2ac ("smb: client: Fix netns refcount imbalance causing leaks and use-after-free"). Link: https://lore.kernel.org/all/2025040248-tummy-smilingly-4240@gregkh/ #[0] Fixes: 4e7f1644f2ac ("smb: client: Fix netns refcount imbalance causing leaks and use-after-free") Signed-off-by: Kuniyuki Iwashima <kuniyu(a)amazon.com> Cc: stable(a)vger.kernel.org --- fs/smb/client/connect.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c index 10a7c28d2d44..137a611c5ab0 100644 --- a/fs/smb/client/connect.c +++ b/fs/smb/client/connect.c @@ -300,7 +300,6 @@ cifs_abort_connection(struct TCP_Server_Info *server) server->ssocket->flags); sock_release(server->ssocket); server->ssocket = NULL; - put_net(cifs_net_ns(server)); } server->sequence_number = 0; server->session_estab = false; @@ -3367,12 +3366,8 @@ generic_ip_connect(struct TCP_Server_Info *server) /* * Grab netns reference for the socket. * - * This reference will be released in several situations: - * - In the failure path before the cifsd thread is started. - * - In the all place where server->socket is released, it is - * also set to NULL. - * - Ultimately in clean_demultiplex_info(), during the final - * teardown. + * It'll be released here, on error, or in clean_demultiplex_info() upon server + * teardown. */ get_net(net); @@ -3388,8 +3383,10 @@ generic_ip_connect(struct TCP_Server_Info *server) } rc = bind_socket(server); - if (rc < 0) + if (rc < 0) { + put_net(cifs_net_ns(server)); return rc; + } /* * Eventually check for other socket options to change from @@ -3444,6 +3441,9 @@ generic_ip_connect(struct TCP_Server_Info *server) (server->rfc1001_sessinit == -1 && sport == htons(RFC1001_PORT))) rc = ip_rfc1001_connect(server); + if (rc < 0) + put_net(cifs_net_ns(server)); + return rc; } -- 2.48.1

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