January 2025 - Linux-stable-mirror

FAILED: patch "[PATCH] mm: reinstate ability to map write-sealed memfd mappings" 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 8ec396d05d1b737c87311fb7311f753b02c2a6b1 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010654-streak-cornfield-7b88@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 8ec396d05d1b737c87311fb7311f753b02c2a6b1 Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Date: Thu, 28 Nov 2024 15:06:17 +0000 Subject: [PATCH] mm: reinstate ability to map write-sealed memfd mappings read-only Patch series "mm: reinstate ability to map write-sealed memfd mappings read-only". In commit 158978945f31 ("mm: perform the mapping_map_writable() check after call_mmap()") (and preceding changes in the same series) it became possible to mmap() F_SEAL_WRITE sealed memfd mappings read-only. Commit 5de195060b2e ("mm: resolve faulty mmap_region() error path behaviour") unintentionally undid this logic by moving the mapping_map_writable() check before the shmem_mmap() hook is invoked, thereby regressing this change. This series reworks how we both permit write-sealed mappings being mapped read-only and disallow mprotect() from undoing the write-seal, fixing this regression. We also add a regression test to ensure that we do not accidentally regress this in future. Thanks to Julian Orth for reporting this regression. This patch (of 2): In commit 158978945f31 ("mm: perform the mapping_map_writable() check after call_mmap()") (and preceding changes in the same series) it became possible to mmap() F_SEAL_WRITE sealed memfd mappings read-only. This was previously unnecessarily disallowed, despite the man page documentation indicating that it would be, thereby limiting the usefulness of F_SEAL_WRITE logic. We fixed this by adapting logic that existed for the F_SEAL_FUTURE_WRITE seal (one which disallows future writes to the memfd) to also be used for F_SEAL_WRITE. For background - the F_SEAL_FUTURE_WRITE seal clears VM_MAYWRITE for a read-only mapping to disallow mprotect() from overriding the seal - an operation performed by seal_check_write(), invoked from shmem_mmap(), the f_op->mmap() hook used by shmem mappings. By extending this to F_SEAL_WRITE and critically - checking mapping_map_writable() to determine if we may map the memfd AFTER we invoke shmem_mmap() - the desired logic becomes possible. This is because mapping_map_writable() explicitly checks for VM_MAYWRITE, which we will have cleared. Commit 5de195060b2e ("mm: resolve faulty mmap_region() error path behaviour") unintentionally undid this logic by moving the mapping_map_writable() check before the shmem_mmap() hook is invoked, thereby regressing this change. We reinstate this functionality by moving the check out of shmem_mmap() and instead performing it in do_mmap() at the point at which VMA flags are being determined, which seems in any case to be a more appropriate place in which to make this determination. In order to achieve this we rework memfd seal logic to allow us access to this information using existing logic and eliminate the clearing of VM_MAYWRITE from seal_check_write() which we are performing in do_mmap() instead. Link: https://lkml.kernel.org/r/99fc35d2c62bd2e05571cf60d9f8b843c56069e0.17328047… Fixes: 5de195060b2e ("mm: resolve faulty mmap_region() error path behaviour") Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Reported-by: Julian Orth <ju.orth(a)gmail.com> Closes: https://lore.kernel.org/all/CAHijbEUMhvJTN9Xw1GmbM266FXXv=U7s4L_Jem5x3AaPZx… Cc: Jann Horn <jannh(a)google.com> Cc: Liam R. Howlett <Liam.Howlett(a)Oracle.com> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/include/linux/memfd.h b/include/linux/memfd.h index 3f2cf339ceaf..d437e3070850 100644 --- a/include/linux/memfd.h +++ b/include/linux/memfd.h @@ -7,6 +7,7 @@ #ifdef CONFIG_MEMFD_CREATE extern long memfd_fcntl(struct file *file, unsigned int cmd, unsigned int arg); struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx); +unsigned int *memfd_file_seals_ptr(struct file *file); #else static inline long memfd_fcntl(struct file *f, unsigned int c, unsigned int a) { @@ -16,6 +17,19 @@ static inline struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx) { return ERR_PTR(-EINVAL); } + +static inline unsigned int *memfd_file_seals_ptr(struct file *file) +{ + return NULL; +} #endif +/* Retrieve memfd seals associated with the file, if any. */ +static inline unsigned int memfd_file_seals(struct file *file) +{ + unsigned int *sealsp = memfd_file_seals_ptr(file); + + return sealsp ? *sealsp : 0; +} + #endif /* __LINUX_MEMFD_H */ diff --git a/include/linux/mm.h b/include/linux/mm.h index 338a76ce9083..fb397918c43d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -4101,6 +4101,37 @@ void mem_dump_obj(void *object); static inline void mem_dump_obj(void *object) {} #endif +static inline bool is_write_sealed(int seals) +{ + return seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE); +} + +/** + * is_readonly_sealed - Checks whether write-sealed but mapped read-only, + * in which case writes should be disallowing moving + * forwards. + * @seals: the seals to check + * @vm_flags: the VMA flags to check + * + * Returns whether readonly sealed, in which case writess should be disallowed + * going forward. + */ +static inline bool is_readonly_sealed(int seals, vm_flags_t vm_flags) +{ + /* + * Since an F_SEAL_[FUTURE_]WRITE sealed memfd can be mapped as + * MAP_SHARED and read-only, take care to not allow mprotect to + * revert protections on such mappings. Do this only for shared + * mappings. For private mappings, don't need to mask + * VM_MAYWRITE as we still want them to be COW-writable. + */ + if (is_write_sealed(seals) && + ((vm_flags & (VM_SHARED | VM_WRITE)) == VM_SHARED)) + return true; + + return false; +} + /** * seal_check_write - Check for F_SEAL_WRITE or F_SEAL_FUTURE_WRITE flags and * handle them. @@ -4112,24 +4143,15 @@ static inline void mem_dump_obj(void *object) {} */ static inline int seal_check_write(int seals, struct vm_area_struct *vma) { - if (seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) { - /* - * New PROT_WRITE and MAP_SHARED mmaps are not allowed when - * write seals are active. - */ - if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE)) - return -EPERM; + if (!is_write_sealed(seals)) + return 0; - /* - * Since an F_SEAL_[FUTURE_]WRITE sealed memfd can be mapped as - * MAP_SHARED and read-only, take care to not allow mprotect to - * revert protections on such mappings. Do this only for shared - * mappings. For private mappings, don't need to mask - * VM_MAYWRITE as we still want them to be COW-writable. - */ - if (vma->vm_flags & VM_SHARED) - vm_flags_clear(vma, VM_MAYWRITE); - } + /* + * New PROT_WRITE and MAP_SHARED mmaps are not allowed when + * write seals are active. + */ + if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE)) + return -EPERM; return 0; } diff --git a/mm/memfd.c b/mm/memfd.c index c17c3ea701a1..35a370d75c9a 100644 --- a/mm/memfd.c +++ b/mm/memfd.c @@ -170,7 +170,7 @@ static int memfd_wait_for_pins(struct address_space *mapping) return error; } -static unsigned int *memfd_file_seals_ptr(struct file *file) +unsigned int *memfd_file_seals_ptr(struct file *file) { if (shmem_file(file)) return &SHMEM_I(file_inode(file))->seals; diff --git a/mm/mmap.c b/mm/mmap.c index d32b7e701058..16f8e8be01f8 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -47,6 +47,7 @@ #include <linux/oom.h> #include <linux/sched/mm.h> #include <linux/ksm.h> +#include <linux/memfd.h> #include <linux/uaccess.h> #include <asm/cacheflush.h> @@ -368,6 +369,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr, if (file) { struct inode *inode = file_inode(file); + unsigned int seals = memfd_file_seals(file); unsigned long flags_mask; if (!file_mmap_ok(file, inode, pgoff, len)) @@ -408,6 +410,8 @@ unsigned long do_mmap(struct file *file, unsigned long addr, vm_flags |= VM_SHARED | VM_MAYSHARE; if (!(file->f_mode & FMODE_WRITE)) vm_flags &= ~(VM_MAYWRITE | VM_SHARED); + else if (is_readonly_sealed(seals, vm_flags)) + vm_flags &= ~VM_MAYWRITE; fallthrough; case MAP_PRIVATE: if (!(file->f_mode & FMODE_READ))

23 hours, 19 minutes

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FAILED: patch "[PATCH] mm: zswap: fix race between [de]compression and CPU hotunplug" 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 eaebeb93922ca6ab0dd92027b73d0112701706ef # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010631-rice-vocalize-bfc1@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From eaebeb93922ca6ab0dd92027b73d0112701706ef Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed(a)google.com> Date: Thu, 19 Dec 2024 21:24:37 +0000 Subject: [PATCH] mm: zswap: fix race between [de]compression and CPU hotunplug In zswap_compress() and zswap_decompress(), the per-CPU acomp_ctx of the current CPU at the beginning of the operation is retrieved and used throughout. However, since neither preemption nor migration are disabled, it is possible that the operation continues on a different CPU. If the original CPU is hotunplugged while the acomp_ctx is still in use, we run into a UAF bug as the resources attached to the acomp_ctx are freed during hotunplug in zswap_cpu_comp_dead(). The problem was introduced in commit 1ec3b5fe6eec ("mm/zswap: move to use crypto_acomp API for hardware acceleration") when the switch to the crypto_acomp API was made. Prior to that, the per-CPU crypto_comp was retrieved using get_cpu_ptr() which disables preemption and makes sure the CPU cannot go away from under us. Preemption cannot be disabled with the crypto_acomp API as a sleepable context is needed. Commit 8ba2f844f050 ("mm/zswap: change per-cpu mutex and buffer to per-acomp_ctx") increased the UAF surface area by making the per-CPU buffers dynamic, adding yet another resource that can be freed from under zswap compression/decompression by CPU hotunplug. There are a few ways to fix this: (a) Add a refcount for acomp_ctx. (b) Disable migration while using the per-CPU acomp_ctx. (c) Disable CPU hotunplug while using the per-CPU acomp_ctx by holding the CPUs read lock. Implement (c) since it's simpler than (a), and (b) involves using migrate_disable() which is apparently undesired (see huge comment in include/linux/preempt.h). Link: https://lkml.kernel.org/r/20241219212437.2714151-1-yosryahmed@google.com Fixes: 1ec3b5fe6eec ("mm/zswap: move to use crypto_acomp API for hardware acceleration") Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com> Reported-by: Johannes Weiner <hannes(a)cmpxchg.org> Closes: https://lore.kernel.org/lkml/20241113213007.GB1564047@cmpxchg.org/ Reported-by: Sam Sun <samsun1006219(a)gmail.com> Closes: https://lore.kernel.org/lkml/CAEkJfYMtSdM5HceNsXUDf5haghD5+o2e7Qv4OcuruL4tP… Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev> Acked-by: Barry Song <baohua(a)kernel.org> Reviewed-by: Nhat Pham <nphamcs(a)gmail.com> Cc: Vitaly Wool <vitalywool(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/zswap.c b/mm/zswap.c index f6316b66fb23..5a27af8d86ea 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -880,6 +880,18 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) return 0; } +/* Prevent CPU hotplug from freeing up the per-CPU acomp_ctx resources */ +static struct crypto_acomp_ctx *acomp_ctx_get_cpu(struct crypto_acomp_ctx __percpu *acomp_ctx) +{ + cpus_read_lock(); + return raw_cpu_ptr(acomp_ctx); +} + +static void acomp_ctx_put_cpu(void) +{ + cpus_read_unlock(); +} + static bool zswap_compress(struct page *page, struct zswap_entry *entry, struct zswap_pool *pool) { @@ -893,8 +905,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, gfp_t gfp; u8 *dst; - acomp_ctx = raw_cpu_ptr(pool->acomp_ctx); - + acomp_ctx = acomp_ctx_get_cpu(pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); dst = acomp_ctx->buffer; @@ -950,6 +961,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, zswap_reject_alloc_fail++; mutex_unlock(&acomp_ctx->mutex); + acomp_ctx_put_cpu(); return comp_ret == 0 && alloc_ret == 0; } @@ -960,7 +972,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) struct crypto_acomp_ctx *acomp_ctx; u8 *src; - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); + acomp_ctx = acomp_ctx_get_cpu(entry->pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); @@ -990,6 +1002,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) if (src != acomp_ctx->buffer) zpool_unmap_handle(zpool, entry->handle); + acomp_ctx_put_cpu(); } /*********************************

23 hours, 28 minutes

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FAILED: patch "[PATCH] mm: zswap: fix race between [de]compression and CPU hotunplug" 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 eaebeb93922ca6ab0dd92027b73d0112701706ef # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010630-chewable-chewer-e363@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From eaebeb93922ca6ab0dd92027b73d0112701706ef Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed(a)google.com> Date: Thu, 19 Dec 2024 21:24:37 +0000 Subject: [PATCH] mm: zswap: fix race between [de]compression and CPU hotunplug In zswap_compress() and zswap_decompress(), the per-CPU acomp_ctx of the current CPU at the beginning of the operation is retrieved and used throughout. However, since neither preemption nor migration are disabled, it is possible that the operation continues on a different CPU. If the original CPU is hotunplugged while the acomp_ctx is still in use, we run into a UAF bug as the resources attached to the acomp_ctx are freed during hotunplug in zswap_cpu_comp_dead(). The problem was introduced in commit 1ec3b5fe6eec ("mm/zswap: move to use crypto_acomp API for hardware acceleration") when the switch to the crypto_acomp API was made. Prior to that, the per-CPU crypto_comp was retrieved using get_cpu_ptr() which disables preemption and makes sure the CPU cannot go away from under us. Preemption cannot be disabled with the crypto_acomp API as a sleepable context is needed. Commit 8ba2f844f050 ("mm/zswap: change per-cpu mutex and buffer to per-acomp_ctx") increased the UAF surface area by making the per-CPU buffers dynamic, adding yet another resource that can be freed from under zswap compression/decompression by CPU hotunplug. There are a few ways to fix this: (a) Add a refcount for acomp_ctx. (b) Disable migration while using the per-CPU acomp_ctx. (c) Disable CPU hotunplug while using the per-CPU acomp_ctx by holding the CPUs read lock. Implement (c) since it's simpler than (a), and (b) involves using migrate_disable() which is apparently undesired (see huge comment in include/linux/preempt.h). Link: https://lkml.kernel.org/r/20241219212437.2714151-1-yosryahmed@google.com Fixes: 1ec3b5fe6eec ("mm/zswap: move to use crypto_acomp API for hardware acceleration") Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com> Reported-by: Johannes Weiner <hannes(a)cmpxchg.org> Closes: https://lore.kernel.org/lkml/20241113213007.GB1564047@cmpxchg.org/ Reported-by: Sam Sun <samsun1006219(a)gmail.com> Closes: https://lore.kernel.org/lkml/CAEkJfYMtSdM5HceNsXUDf5haghD5+o2e7Qv4OcuruL4tP… Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev> Acked-by: Barry Song <baohua(a)kernel.org> Reviewed-by: Nhat Pham <nphamcs(a)gmail.com> Cc: Vitaly Wool <vitalywool(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/zswap.c b/mm/zswap.c index f6316b66fb23..5a27af8d86ea 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -880,6 +880,18 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) return 0; } +/* Prevent CPU hotplug from freeing up the per-CPU acomp_ctx resources */ +static struct crypto_acomp_ctx *acomp_ctx_get_cpu(struct crypto_acomp_ctx __percpu *acomp_ctx) +{ + cpus_read_lock(); + return raw_cpu_ptr(acomp_ctx); +} + +static void acomp_ctx_put_cpu(void) +{ + cpus_read_unlock(); +} + static bool zswap_compress(struct page *page, struct zswap_entry *entry, struct zswap_pool *pool) { @@ -893,8 +905,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, gfp_t gfp; u8 *dst; - acomp_ctx = raw_cpu_ptr(pool->acomp_ctx); - + acomp_ctx = acomp_ctx_get_cpu(pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); dst = acomp_ctx->buffer; @@ -950,6 +961,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, zswap_reject_alloc_fail++; mutex_unlock(&acomp_ctx->mutex); + acomp_ctx_put_cpu(); return comp_ret == 0 && alloc_ret == 0; } @@ -960,7 +972,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) struct crypto_acomp_ctx *acomp_ctx; u8 *src; - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); + acomp_ctx = acomp_ctx_get_cpu(entry->pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); @@ -990,6 +1002,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) if (src != acomp_ctx->buffer) zpool_unmap_handle(zpool, entry->handle); + acomp_ctx_put_cpu(); } /*********************************

23 hours, 28 minutes

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FAILED: patch "[PATCH] mm: zswap: fix race between [de]compression and CPU hotunplug" 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 eaebeb93922ca6ab0dd92027b73d0112701706ef # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010629-undusted-massager-f7d9@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From eaebeb93922ca6ab0dd92027b73d0112701706ef Mon Sep 17 00:00:00 2001 From: Yosry Ahmed <yosryahmed(a)google.com> Date: Thu, 19 Dec 2024 21:24:37 +0000 Subject: [PATCH] mm: zswap: fix race between [de]compression and CPU hotunplug In zswap_compress() and zswap_decompress(), the per-CPU acomp_ctx of the current CPU at the beginning of the operation is retrieved and used throughout. However, since neither preemption nor migration are disabled, it is possible that the operation continues on a different CPU. If the original CPU is hotunplugged while the acomp_ctx is still in use, we run into a UAF bug as the resources attached to the acomp_ctx are freed during hotunplug in zswap_cpu_comp_dead(). The problem was introduced in commit 1ec3b5fe6eec ("mm/zswap: move to use crypto_acomp API for hardware acceleration") when the switch to the crypto_acomp API was made. Prior to that, the per-CPU crypto_comp was retrieved using get_cpu_ptr() which disables preemption and makes sure the CPU cannot go away from under us. Preemption cannot be disabled with the crypto_acomp API as a sleepable context is needed. Commit 8ba2f844f050 ("mm/zswap: change per-cpu mutex and buffer to per-acomp_ctx") increased the UAF surface area by making the per-CPU buffers dynamic, adding yet another resource that can be freed from under zswap compression/decompression by CPU hotunplug. There are a few ways to fix this: (a) Add a refcount for acomp_ctx. (b) Disable migration while using the per-CPU acomp_ctx. (c) Disable CPU hotunplug while using the per-CPU acomp_ctx by holding the CPUs read lock. Implement (c) since it's simpler than (a), and (b) involves using migrate_disable() which is apparently undesired (see huge comment in include/linux/preempt.h). Link: https://lkml.kernel.org/r/20241219212437.2714151-1-yosryahmed@google.com Fixes: 1ec3b5fe6eec ("mm/zswap: move to use crypto_acomp API for hardware acceleration") Signed-off-by: Yosry Ahmed <yosryahmed(a)google.com> Reported-by: Johannes Weiner <hannes(a)cmpxchg.org> Closes: https://lore.kernel.org/lkml/20241113213007.GB1564047@cmpxchg.org/ Reported-by: Sam Sun <samsun1006219(a)gmail.com> Closes: https://lore.kernel.org/lkml/CAEkJfYMtSdM5HceNsXUDf5haghD5+o2e7Qv4OcuruL4tP… Reviewed-by: Chengming Zhou <chengming.zhou(a)linux.dev> Acked-by: Barry Song <baohua(a)kernel.org> Reviewed-by: Nhat Pham <nphamcs(a)gmail.com> Cc: Vitaly Wool <vitalywool(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> diff --git a/mm/zswap.c b/mm/zswap.c index f6316b66fb23..5a27af8d86ea 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -880,6 +880,18 @@ static int zswap_cpu_comp_dead(unsigned int cpu, struct hlist_node *node) return 0; } +/* Prevent CPU hotplug from freeing up the per-CPU acomp_ctx resources */ +static struct crypto_acomp_ctx *acomp_ctx_get_cpu(struct crypto_acomp_ctx __percpu *acomp_ctx) +{ + cpus_read_lock(); + return raw_cpu_ptr(acomp_ctx); +} + +static void acomp_ctx_put_cpu(void) +{ + cpus_read_unlock(); +} + static bool zswap_compress(struct page *page, struct zswap_entry *entry, struct zswap_pool *pool) { @@ -893,8 +905,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, gfp_t gfp; u8 *dst; - acomp_ctx = raw_cpu_ptr(pool->acomp_ctx); - + acomp_ctx = acomp_ctx_get_cpu(pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); dst = acomp_ctx->buffer; @@ -950,6 +961,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry, zswap_reject_alloc_fail++; mutex_unlock(&acomp_ctx->mutex); + acomp_ctx_put_cpu(); return comp_ret == 0 && alloc_ret == 0; } @@ -960,7 +972,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) struct crypto_acomp_ctx *acomp_ctx; u8 *src; - acomp_ctx = raw_cpu_ptr(entry->pool->acomp_ctx); + acomp_ctx = acomp_ctx_get_cpu(entry->pool->acomp_ctx); mutex_lock(&acomp_ctx->mutex); src = zpool_map_handle(zpool, entry->handle, ZPOOL_MM_RO); @@ -990,6 +1002,7 @@ static void zswap_decompress(struct zswap_entry *entry, struct folio *folio) if (src != acomp_ctx->buffer) zpool_unmap_handle(zpool, entry->handle); + acomp_ctx_put_cpu(); } /*********************************

23 hours, 28 minutes

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FAILED: patch "[PATCH] gve: clean XDP queues in gve_tx_stop_ring_gqi" 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 6321f5fb70d502d95de8a212a7b484c297ec9644 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010642-annually-shirt-b4e1@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 6321f5fb70d502d95de8a212a7b484c297ec9644 Mon Sep 17 00:00:00 2001 From: Joshua Washington <joshwash(a)google.com> Date: Wed, 18 Dec 2024 05:34:11 -0800 Subject: [PATCH] gve: clean XDP queues in gve_tx_stop_ring_gqi When stopping XDP TX rings, the XDP clean function needs to be called to clean out the entire queue, similar to what happens in the normal TX queue case. Otherwise, the FIFO won't be cleared correctly, and xsk_tx_completed won't be reported. Fixes: 75eaae158b1b ("gve: Add XDP DROP and TX support for GQI-QPL format") Cc: stable(a)vger.kernel.org Signed-off-by: Joshua Washington <joshwash(a)google.com> Signed-off-by: Praveen Kaligineedi <pkaligineedi(a)google.com> Reviewed-by: Praveen Kaligineedi <pkaligineedi(a)google.com> Reviewed-by: Willem de Bruijn <willemb(a)google.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> diff --git a/drivers/net/ethernet/google/gve/gve_tx.c b/drivers/net/ethernet/google/gve/gve_tx.c index e7fb7d6d283d..83ad278ec91f 100644 --- a/drivers/net/ethernet/google/gve/gve_tx.c +++ b/drivers/net/ethernet/google/gve/gve_tx.c @@ -206,7 +206,10 @@ void gve_tx_stop_ring_gqi(struct gve_priv *priv, int idx) return; gve_remove_napi(priv, ntfy_idx); - gve_clean_tx_done(priv, tx, priv->tx_desc_cnt, false); + if (tx->q_num < priv->tx_cfg.num_queues) + gve_clean_tx_done(priv, tx, priv->tx_desc_cnt, false); + else + gve_clean_xdp_done(priv, tx, priv->tx_desc_cnt); netdev_tx_reset_queue(tx->netdev_txq); gve_tx_remove_from_block(priv, idx); }

23 hours, 30 minutes

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FAILED: patch "[PATCH] drm: adv7511: Fix use-after-free in adv7533_attach_dsi()" 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>. 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-5.10.y git checkout FETCH_HEAD git cherry-pick -x 81adbd3ff21c1182e06aa02c6be0bfd9ea02d8e8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010606-rifling-dreamily-f58e@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 81adbd3ff21c1182e06aa02c6be0bfd9ea02d8e8 Mon Sep 17 00:00:00 2001 From: Biju Das <biju.das.jz(a)bp.renesas.com> Date: Tue, 19 Nov 2024 19:20:29 +0000 Subject: [PATCH] drm: adv7511: Fix use-after-free in adv7533_attach_dsi() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The host_node pointer was assigned and freed in adv7533_parse_dt(), and later, adv7533_attach_dsi() uses the same. Fix this use-after-free issue by dropping of_node_put() in adv7533_parse_dt() and calling of_node_put() in error path of probe() and also in the remove(). Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device") Cc: stable(a)vger.kernel.org Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas(a)ideasonboard.com> Signed-off-by: Biju Das <biju.das.jz(a)bp.renesas.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241119192040.152657-2-biju.… Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index eb5919b38263..a13b3d8ab6ac 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1241,8 +1241,10 @@ static int adv7511_probe(struct i2c_client *i2c) return ret; ret = adv7511_init_regulators(adv7511); - if (ret) - return dev_err_probe(dev, ret, "failed to init regulators\n"); + if (ret) { + dev_err_probe(dev, ret, "failed to init regulators\n"); + goto err_of_node_put; + } /* * The power down GPIO is optional. If present, toggle it from active to @@ -1363,6 +1365,8 @@ static int adv7511_probe(struct i2c_client *i2c) i2c_unregister_device(adv7511->i2c_edid); uninit_regulators: adv7511_uninit_regulators(adv7511); +err_of_node_put: + of_node_put(adv7511->host_node); return ret; } @@ -1371,6 +1375,8 @@ static void adv7511_remove(struct i2c_client *i2c) { struct adv7511 *adv7511 = i2c_get_clientdata(i2c); + of_node_put(adv7511->host_node); + adv7511_uninit_regulators(adv7511); drm_bridge_remove(&adv7511->bridge); diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c index 4481489aaf5e..5f195e91b3e6 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c @@ -181,8 +181,6 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv) if (!adv->host_node) return -ENODEV; - of_node_put(adv->host_node); - adv->use_timing_gen = !of_property_read_bool(np, "adi,disable-timing-generator");

23 hours, 47 minutes

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FAILED: patch "[PATCH] drm: adv7511: Fix use-after-free in adv7533_attach_dsi()" 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>. 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-5.4.y git checkout FETCH_HEAD git cherry-pick -x 81adbd3ff21c1182e06aa02c6be0bfd9ea02d8e8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010606-prude-geiger-28e3@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 81adbd3ff21c1182e06aa02c6be0bfd9ea02d8e8 Mon Sep 17 00:00:00 2001 From: Biju Das <biju.das.jz(a)bp.renesas.com> Date: Tue, 19 Nov 2024 19:20:29 +0000 Subject: [PATCH] drm: adv7511: Fix use-after-free in adv7533_attach_dsi() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The host_node pointer was assigned and freed in adv7533_parse_dt(), and later, adv7533_attach_dsi() uses the same. Fix this use-after-free issue by dropping of_node_put() in adv7533_parse_dt() and calling of_node_put() in error path of probe() and also in the remove(). Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device") Cc: stable(a)vger.kernel.org Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas(a)ideasonboard.com> Signed-off-by: Biju Das <biju.das.jz(a)bp.renesas.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241119192040.152657-2-biju.… Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index eb5919b38263..a13b3d8ab6ac 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1241,8 +1241,10 @@ static int adv7511_probe(struct i2c_client *i2c) return ret; ret = adv7511_init_regulators(adv7511); - if (ret) - return dev_err_probe(dev, ret, "failed to init regulators\n"); + if (ret) { + dev_err_probe(dev, ret, "failed to init regulators\n"); + goto err_of_node_put; + } /* * The power down GPIO is optional. If present, toggle it from active to @@ -1363,6 +1365,8 @@ static int adv7511_probe(struct i2c_client *i2c) i2c_unregister_device(adv7511->i2c_edid); uninit_regulators: adv7511_uninit_regulators(adv7511); +err_of_node_put: + of_node_put(adv7511->host_node); return ret; } @@ -1371,6 +1375,8 @@ static void adv7511_remove(struct i2c_client *i2c) { struct adv7511 *adv7511 = i2c_get_clientdata(i2c); + of_node_put(adv7511->host_node); + adv7511_uninit_regulators(adv7511); drm_bridge_remove(&adv7511->bridge); diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c index 4481489aaf5e..5f195e91b3e6 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c @@ -181,8 +181,6 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv) if (!adv->host_node) return -ENODEV; - of_node_put(adv->host_node); - adv->use_timing_gen = !of_property_read_bool(np, "adi,disable-timing-generator");

23 hours, 47 minutes

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FAILED: patch "[PATCH] drm: adv7511: Fix use-after-free in adv7533_attach_dsi()" 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 81adbd3ff21c1182e06aa02c6be0bfd9ea02d8e8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010605-quit-rockfish-a0e8@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 81adbd3ff21c1182e06aa02c6be0bfd9ea02d8e8 Mon Sep 17 00:00:00 2001 From: Biju Das <biju.das.jz(a)bp.renesas.com> Date: Tue, 19 Nov 2024 19:20:29 +0000 Subject: [PATCH] drm: adv7511: Fix use-after-free in adv7533_attach_dsi() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The host_node pointer was assigned and freed in adv7533_parse_dt(), and later, adv7533_attach_dsi() uses the same. Fix this use-after-free issue by dropping of_node_put() in adv7533_parse_dt() and calling of_node_put() in error path of probe() and also in the remove(). Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device") Cc: stable(a)vger.kernel.org Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas(a)ideasonboard.com> Signed-off-by: Biju Das <biju.das.jz(a)bp.renesas.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241119192040.152657-2-biju.… Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index eb5919b38263..a13b3d8ab6ac 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1241,8 +1241,10 @@ static int adv7511_probe(struct i2c_client *i2c) return ret; ret = adv7511_init_regulators(adv7511); - if (ret) - return dev_err_probe(dev, ret, "failed to init regulators\n"); + if (ret) { + dev_err_probe(dev, ret, "failed to init regulators\n"); + goto err_of_node_put; + } /* * The power down GPIO is optional. If present, toggle it from active to @@ -1363,6 +1365,8 @@ static int adv7511_probe(struct i2c_client *i2c) i2c_unregister_device(adv7511->i2c_edid); uninit_regulators: adv7511_uninit_regulators(adv7511); +err_of_node_put: + of_node_put(adv7511->host_node); return ret; } @@ -1371,6 +1375,8 @@ static void adv7511_remove(struct i2c_client *i2c) { struct adv7511 *adv7511 = i2c_get_clientdata(i2c); + of_node_put(adv7511->host_node); + adv7511_uninit_regulators(adv7511); drm_bridge_remove(&adv7511->bridge); diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c index 4481489aaf5e..5f195e91b3e6 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c @@ -181,8 +181,6 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv) if (!adv->host_node) return -ENODEV; - of_node_put(adv->host_node); - adv->use_timing_gen = !of_property_read_bool(np, "adi,disable-timing-generator");

23 hours, 47 minutes

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FAILED: patch "[PATCH] drm: adv7511: Fix use-after-free in adv7533_attach_dsi()" 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 81adbd3ff21c1182e06aa02c6be0bfd9ea02d8e8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010604-resilient-unpaired-7bb7@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 81adbd3ff21c1182e06aa02c6be0bfd9ea02d8e8 Mon Sep 17 00:00:00 2001 From: Biju Das <biju.das.jz(a)bp.renesas.com> Date: Tue, 19 Nov 2024 19:20:29 +0000 Subject: [PATCH] drm: adv7511: Fix use-after-free in adv7533_attach_dsi() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The host_node pointer was assigned and freed in adv7533_parse_dt(), and later, adv7533_attach_dsi() uses the same. Fix this use-after-free issue by dropping of_node_put() in adv7533_parse_dt() and calling of_node_put() in error path of probe() and also in the remove(). Fixes: 1e4d58cd7f88 ("drm/bridge: adv7533: Create a MIPI DSI device") Cc: stable(a)vger.kernel.org Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas(a)ideasonboard.com> Signed-off-by: Biju Das <biju.das.jz(a)bp.renesas.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241119192040.152657-2-biju.… Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index eb5919b38263..a13b3d8ab6ac 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -1241,8 +1241,10 @@ static int adv7511_probe(struct i2c_client *i2c) return ret; ret = adv7511_init_regulators(adv7511); - if (ret) - return dev_err_probe(dev, ret, "failed to init regulators\n"); + if (ret) { + dev_err_probe(dev, ret, "failed to init regulators\n"); + goto err_of_node_put; + } /* * The power down GPIO is optional. If present, toggle it from active to @@ -1363,6 +1365,8 @@ static int adv7511_probe(struct i2c_client *i2c) i2c_unregister_device(adv7511->i2c_edid); uninit_regulators: adv7511_uninit_regulators(adv7511); +err_of_node_put: + of_node_put(adv7511->host_node); return ret; } @@ -1371,6 +1375,8 @@ static void adv7511_remove(struct i2c_client *i2c) { struct adv7511 *adv7511 = i2c_get_clientdata(i2c); + of_node_put(adv7511->host_node); + adv7511_uninit_regulators(adv7511); drm_bridge_remove(&adv7511->bridge); diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c index 4481489aaf5e..5f195e91b3e6 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c @@ -181,8 +181,6 @@ int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv) if (!adv->host_node) return -ENODEV; - of_node_put(adv->host_node); - adv->use_timing_gen = !of_property_read_bool(np, "adi,disable-timing-generator");

23 hours, 47 minutes

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FAILED: patch "[PATCH] workqueue: Do not warn when cancelling WQ_MEM_RECLAIM work" 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>. 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-5.4.y git checkout FETCH_HEAD git cherry-pick -x de35994ecd2dd6148ab5a6c5050a1670a04dec77 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025010656-establish-cleat-3ed7@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From de35994ecd2dd6148ab5a6c5050a1670a04dec77 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Date: Thu, 19 Dec 2024 09:30:30 +0000 Subject: [PATCH] workqueue: Do not warn when cancelling WQ_MEM_RECLAIM work from !WQ_MEM_RECLAIM worker MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit After commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") amdgpu started seeing the following warning: [ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK> The intent of the verifcation done in check_flush_depedency is to ensure forward progress during memory reclaim, by flagging cases when either a memory reclaim process, or a memory reclaim work item is flushed from a context not marked as memory reclaim safe. This is correct when flushing, but when called from the cancel(_delayed)_work_sync() paths it is a false positive because work is either already running, or will not be running at all. Therefore cancelling it is safe and we can relax the warning criteria by letting the helper know of the calling context. Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin(a)igalia.com> Fixes: fca839c00a12 ("workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue") References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Cc: Tejun Heo <tj(a)kernel.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Lai Jiangshan <jiangshanlai(a)gmail.com> Cc: Alex Deucher <alexander.deucher(a)amd.com> Cc: Christian König <christian.koenig(a)amd.com Cc: Matthew Brost <matthew.brost(a)intel.com> Cc: <stable(a)vger.kernel.org> # v4.5+ Signed-off-by: Tejun Heo <tj(a)kernel.org> diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 8b07576814a5..8336218ec4b8 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -3680,23 +3680,27 @@ void workqueue_softirq_dead(unsigned int cpu) * check_flush_dependency - check for flush dependency sanity * @target_wq: workqueue being flushed * @target_work: work item being flushed (NULL for workqueue flushes) + * @from_cancel: are we called from the work cancel path * * %current is trying to flush the whole @target_wq or @target_work on it. - * If @target_wq doesn't have %WQ_MEM_RECLAIM, verify that %current is not - * reclaiming memory or running on a workqueue which doesn't have - * %WQ_MEM_RECLAIM as that can break forward-progress guarantee leading to - * a deadlock. + * If this is not the cancel path (which implies work being flushed is either + * already running, or will not be at all), check if @target_wq doesn't have + * %WQ_MEM_RECLAIM and verify that %current is not reclaiming memory or running + * on a workqueue which doesn't have %WQ_MEM_RECLAIM as that can break forward- + * progress guarantee leading to a deadlock. */ static void check_flush_dependency(struct workqueue_struct *target_wq, - struct work_struct *target_work) + struct work_struct *target_work, + bool from_cancel) { - work_func_t target_func = target_work ? target_work->func : NULL; + work_func_t target_func; struct worker *worker; - if (target_wq->flags & WQ_MEM_RECLAIM) + if (from_cancel || target_wq->flags & WQ_MEM_RECLAIM) return; worker = current_wq_worker(); + target_func = target_work ? target_work->func : NULL; WARN_ONCE(current->flags & PF_MEMALLOC, "workqueue: PF_MEMALLOC task %d(%s) is flushing !WQ_MEM_RECLAIM %s:%ps", @@ -3980,7 +3984,7 @@ void __flush_workqueue(struct workqueue_struct *wq) list_add_tail(&this_flusher.list, &wq->flusher_overflow); } - check_flush_dependency(wq, NULL); + check_flush_dependency(wq, NULL, false); mutex_unlock(&wq->mutex); @@ -4155,7 +4159,7 @@ static bool start_flush_work(struct work_struct *work, struct wq_barrier *barr, } wq = pwq->wq; - check_flush_dependency(wq, work); + check_flush_dependency(wq, work, from_cancel); insert_wq_barrier(pwq, barr, work, worker); raw_spin_unlock_irq(&pool->lock);

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