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[PATCH 6.12.y] proc: fix the issue of proc_mem_open returning NULL

by Jakub Acs

From: Penglei Jiang <superman.xpt(a)gmail.com> [ Upstream commit 65c66047259fad1b868d4454bc5af95b46a5f954 ] proc_mem_open() can return an errno, NULL, or mm_struct*. If it fails to acquire mm, it returns NULL, but the caller does not check for the case when the return value is NULL. The following conditions lead to failure in acquiring mm: - The task is a kernel thread (PF_KTHREAD) - The task is exiting (PF_EXITING) Changes: - Add documentation comments for the return value of proc_mem_open(). - Add checks in the caller to return -ESRCH when proc_mem_open() returns NULL. Link: https://lkml.kernel.org/r/20250404063357.78891-1-superman.xpt@gmail.com Reported-by: syzbot+f9238a0a31f9b5603fef(a)syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000f52642060d4e3750@google.com Signed-off-by: Penglei Jiang <superman.xpt(a)gmail.com> Cc: Al Viro <viro(a)zeniv.linux.org.uk> Cc: Adrian Ratiu <adrian.ratiu(a)collabora.com> Cc: Christian Brauner <brauner(a)kernel.org> Cc: Felix Moessbauer <felix.moessbauer(a)siemens.com> Cc: Jeff layton <jlayton(a)kernel.org> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Mateusz Guzik <mjguzik(a)gmail.com> Cc: Thomas Gleinxer <tglx(a)linutronix.de> Cc: xu xin <xu.xin16(a)zte.com.cn> Cc: Alexey Dobriyan <adobriyan(a)gmail.com> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> [ acsjakub: applied cleanly ] Signed-off-by: Jakub Acs <acsjakub(a)amazon.de> --- fs/proc/base.c | 12 +++++++++--- fs/proc/task_mmu.c | 12 ++++++------ fs/proc/task_nommu.c | 4 ++-- 3 files changed, 17 insertions(+), 11 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index a2541f5204af..d060af34a6e8 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -828,7 +828,13 @@ static const struct file_operations proc_single_file_operations = { .release = single_release, }; - +/* + * proc_mem_open() can return errno, NULL or mm_struct*. + * + * - Returns NULL if the task has no mm (PF_KTHREAD or PF_EXITING) + * - Returns mm_struct* on success + * - Returns error code on failure + */ struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode) { struct task_struct *task = get_proc_task(inode); @@ -853,8 +859,8 @@ static int __mem_open(struct inode *inode, struct file *file, unsigned int mode) { struct mm_struct *mm = proc_mem_open(inode, mode); - if (IS_ERR(mm)) - return PTR_ERR(mm); + if (IS_ERR_OR_NULL(mm)) + return mm ? PTR_ERR(mm) : -ESRCH; file->private_data = mm; return 0; diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 8f5ad591d762..08a06fd37f0e 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -212,8 +212,8 @@ static int proc_maps_open(struct inode *inode, struct file *file, priv->inode = inode; priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); - if (IS_ERR(priv->mm)) { - int err = PTR_ERR(priv->mm); + if (IS_ERR_OR_NULL(priv->mm)) { + int err = priv->mm ? PTR_ERR(priv->mm) : -ESRCH; seq_release_private(inode, file); return err; @@ -1316,8 +1316,8 @@ static int smaps_rollup_open(struct inode *inode, struct file *file) priv->inode = inode; priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); - if (IS_ERR(priv->mm)) { - ret = PTR_ERR(priv->mm); + if (IS_ERR_OR_NULL(priv->mm)) { + ret = priv->mm ? PTR_ERR(priv->mm) : -ESRCH; single_release(inode, file); goto out_free; @@ -2049,8 +2049,8 @@ static int pagemap_open(struct inode *inode, struct file *file) struct mm_struct *mm; mm = proc_mem_open(inode, PTRACE_MODE_READ); - if (IS_ERR(mm)) - return PTR_ERR(mm); + if (IS_ERR_OR_NULL(mm)) + return mm ? PTR_ERR(mm) : -ESRCH; file->private_data = mm; return 0; } diff --git a/fs/proc/task_nommu.c b/fs/proc/task_nommu.c index bce674533000..59bfd61d653a 100644 --- a/fs/proc/task_nommu.c +++ b/fs/proc/task_nommu.c @@ -260,8 +260,8 @@ static int maps_open(struct inode *inode, struct file *file, priv->inode = inode; priv->mm = proc_mem_open(inode, PTRACE_MODE_READ); - if (IS_ERR(priv->mm)) { - int err = PTR_ERR(priv->mm); + if (IS_ERR_OR_NULL(priv->mm)) { + int err = priv->mm ? PTR_ERR(priv->mm) : -ESRCH; seq_release_private(inode, file); return err; -- 2.47.3 Amazon Web Services Development Center Germany GmbH Tamara-Danz-Str. 13 10243 Berlin Geschaeftsfuehrung: Christian Schlaeger, Christof Hellmis Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

5 days, 16 hours

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[PATCH v2] HID: memory leak in dualshock4_get_calibration_data

by Eslam Khafagy

function dualshock4_get_calibration_data allocates memory to pointer buf. however the function may exit prematurely due to transfer_failure in this case it does not handle freeing memory. this patch handles memory deallocation at exit. Reported-by: syzbot+4f5f81e1456a1f645bf8(a)syzkaller.appspotmail.com Tested-by: syzbot+4f5f81e1456a1f645bf8(a)syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/691560c4.a70a0220.3124cb.0019.GAE@google.com/T/ Fixes: 947992c7fa9e0 ("HID: playstation: DS4: Fix calibration workaround for clone devices") Cc: stable(a)vger.kernel.org Signed-off-by: Eslam Khafagy <eslam.medhat1993(a)gmail.com> --- v2: * Adding tag "Cc: stable(a)vger.kernel.org" v1: https://lore.kernel.org/all/20251115022323.1395726-1-eslam.medhat1993@gmail… --- drivers/hid/hid-playstation.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c index 63f6eb9030d1..fef81b7e27c1 100644 --- a/drivers/hid/hid-playstation.c +++ b/drivers/hid/hid-playstation.c @@ -1992,9 +1992,6 @@ static int dualshock4_get_calibration_data(struct dualshock4 *ds4) acc_z_plus = get_unaligned_le16(&buf[31]); acc_z_minus = get_unaligned_le16(&buf[33]); - /* Done parsing the buffer, so let's free it. */ - kfree(buf); - /* * Set gyroscope calibration and normalization parameters. * Data values will be normalized to 1/DS4_GYRO_RES_PER_DEG_S degree/s. @@ -2041,6 +2038,10 @@ static int dualshock4_get_calibration_data(struct dualshock4 *ds4) ds4->accel_calib_data[2].sens_denom = range_2g; transfer_failed: + /* First free buf if still allocated */ + if(buf) + kfree(buf); + /* * Sanity check gyro calibration data. This is needed to prevent crashes * during report handling of virtual, clone or broken devices not implementing -- 2.43.0

5 days, 18 hours

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[PATCH v3] powerpc, mm: Fix mprotect on book3s 32-bit

by Dave Vasilevsky

On 32-bit book3s with hash-MMUs, tlb_flush() was a no-op. This was unnoticed because all uses until recently were for unmaps, and thus handled by __tlb_remove_tlb_entry(). After commit 4a18419f71cd ("mm/mprotect: use mmu_gather") in kernel 5.19, tlb_gather_mmu() started being used for mprotect as well. This caused mprotect to simply not work on these machines: int *ptr = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); *ptr = 1; // force HPTE to be created mprotect(ptr, 4096, PROT_READ); *ptr = 2; // should segfault, but succeeds Fixed by making tlb_flush() actually flush TLB pages. This finally agrees with the behaviour of boot3s64's tlb_flush(). Fixes: 4a18419f71cd ("mm/mprotect: use mmu_gather") Cc: stable(a)vger.kernel.org Reviewed-by: Christophe Leroy <christophe.leroy(a)csgroup.eu> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list(a)gmail.com> Signed-off-by: Dave Vasilevsky <dave(a)vasilevsky.ca> --- Changes in v3: - Fix formatting - Link to v2: https://lore.kernel.org/r/20251111-vasi-mprotect-g3-v2-1-881c94afbc42@vasil… Changes in v2: - Flush entire TLB if full mm is requested. - Link to v1: https://lore.kernel.org/r/20251027-vasi-mprotect-g3-v1-1-3c5187085f9a@vasil… --- arch/powerpc/include/asm/book3s/32/tlbflush.h | 5 ++++- arch/powerpc/mm/book3s32/tlb.c | 9 +++++++++ 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/book3s/32/tlbflush.h b/arch/powerpc/include/asm/book3s/32/tlbflush.h index e43534da5207aa3b0cb3c07b78e29b833c141f3f..4be2200a3c7e1e8307f5ce1f1d5d28047429c106 100644 --- a/arch/powerpc/include/asm/book3s/32/tlbflush.h +++ b/arch/powerpc/include/asm/book3s/32/tlbflush.h @@ -11,6 +11,7 @@ void hash__flush_tlb_mm(struct mm_struct *mm); void hash__flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr); void hash__flush_range(struct mm_struct *mm, unsigned long start, unsigned long end); +void hash__flush_gather(struct mmu_gather *tlb); #ifdef CONFIG_SMP void _tlbie(unsigned long address); @@ -29,7 +30,9 @@ void _tlbia(void); static inline void tlb_flush(struct mmu_gather *tlb) { /* 603 needs to flush the whole TLB here since it doesn't use a hash table. */ - if (!mmu_has_feature(MMU_FTR_HPTE_TABLE)) + if (mmu_has_feature(MMU_FTR_HPTE_TABLE)) + hash__flush_gather(tlb); + else _tlbia(); } diff --git a/arch/powerpc/mm/book3s32/tlb.c b/arch/powerpc/mm/book3s32/tlb.c index 9ad6b56bfec96e989b96f027d075ad5812500854..e54a7b0112322e5818d80facd2e3c7722e6dd520 100644 --- a/arch/powerpc/mm/book3s32/tlb.c +++ b/arch/powerpc/mm/book3s32/tlb.c @@ -105,3 +105,12 @@ void hash__flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr) flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1); } EXPORT_SYMBOL(hash__flush_tlb_page); + +void hash__flush_gather(struct mmu_gather *tlb) +{ + if (tlb->fullmm || tlb->need_flush_all) + hash__flush_tlb_mm(tlb->mm); + else + hash__flush_range(tlb->mm, tlb->start, tlb->end); +} +EXPORT_SYMBOL(hash__flush_gather); --- base-commit: 24172e0d79900908cf5ebf366600616d29c9b417 change-id: 20251027-vasi-mprotect-g3-f8f5278d4140 Best regards, -- Dave Vasilevsky <dave(a)vasilevsky.ca>

6 days, 2 hours

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[PATCH v2 1/2] crypto: scatterwalk - Fix memcpy_sglist() to always succeed

by Eric Biggers

The original implementation of memcpy_sglist() was broken because it didn't handle scatterlists that describe exactly the same memory, which is a case that many callers rely on. The current implementation is broken too because it calls the skcipher_walk functions which can fail. It ignores any errors from those functions. Fix it by replacing it with a new implementation written from scratch. It always succeeds. It's also a bit faster, since it avoids the overhead of skcipher_walk. skcipher_walk includes a lot of functionality (such as alignmask handling) that's irrelevant here. Reported-by: Colin Ian King <coking(a)nvidia.com> Closes: https://lore.kernel.org/r/20251114122620.111623-1-coking@nvidia.com Fixes: 131bdceca1f0 ("crypto: scatterwalk - Add memcpy_sglist") Fixes: 0f8d42bf128d ("crypto: scatterwalk - Move skcipher walk and use it for memcpy_sglist") Cc: stable(a)vger.kernel.org Signed-off-by: Eric Biggers <ebiggers(a)kernel.org> --- crypto/scatterwalk.c | 97 +++++++++++++++++++++++++++++++----- include/crypto/scatterwalk.h | 52 +++++++++++-------- 2 files changed, 115 insertions(+), 34 deletions(-) diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c index 1d010e2a1b1a..b95e5974e327 100644 --- a/crypto/scatterwalk.c +++ b/crypto/scatterwalk.c @@ -99,30 +99,101 @@ void memcpy_to_sglist(struct scatterlist *sg, unsigned int start, scatterwalk_start_at_pos(&walk, sg, start); memcpy_to_scatterwalk(&walk, buf, nbytes); } EXPORT_SYMBOL_GPL(memcpy_to_sglist); +/** + * memcpy_sglist() - Copy data from one scatterlist to another + * @dst: The destination scatterlist. Can be NULL if @nbytes == 0. + * @src: The source scatterlist. Can be NULL if @nbytes == 0. + * @nbytes: Number of bytes to copy + * + * The scatterlists can describe exactly the same memory, in which case this + * function is a no-op. No other overlaps are supported. + * + * Context: Any context + */ void memcpy_sglist(struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) { - struct skcipher_walk walk = {}; + unsigned int src_offset, dst_offset; - if (unlikely(nbytes == 0)) /* in case sg == NULL */ + if (unlikely(nbytes == 0)) /* in case src and/or dst is NULL */ return; - walk.total = nbytes; - - scatterwalk_start(&walk.in, src); - scatterwalk_start(&walk.out, dst); + src_offset = src->offset; + dst_offset = dst->offset; + for (;;) { + /* Compute the length to copy this step. */ + unsigned int len = min3(src->offset + src->length - src_offset, + dst->offset + dst->length - dst_offset, + nbytes); + struct page *src_page = sg_page(src); + struct page *dst_page = sg_page(dst); + const void *src_virt; + void *dst_virt; + + if (IS_ENABLED(CONFIG_HIGHMEM)) { + /* HIGHMEM: we may have to actually map the pages. */ + const unsigned int src_oip = offset_in_page(src_offset); + const unsigned int dst_oip = offset_in_page(dst_offset); + const unsigned int limit = PAGE_SIZE; + + /* Further limit len to not cross a page boundary. */ + len = min3(len, limit - src_oip, limit - dst_oip); + + /* Compute the source and destination pages. */ + src_page += src_offset / PAGE_SIZE; + dst_page += dst_offset / PAGE_SIZE; + + if (src_page != dst_page) { + /* Copy between different pages. */ + memcpy_page(dst_page, dst_oip, + src_page, src_oip, len); + flush_dcache_page(dst_page); + } else if (src_oip != dst_oip) { + /* Copy between different parts of same page. */ + dst_virt = kmap_local_page(dst_page); + memcpy(dst_virt + dst_oip, dst_virt + src_oip, + len); + kunmap_local(dst_virt); + flush_dcache_page(dst_page); + } /* Else, it's the same memory. No action needed. */ + } else { + /* + * !HIGHMEM: no mapping needed. Just work in the linear + * buffer of each sg entry. Note that we can cross page + * boundaries, as they are not significant in this case. + */ + src_virt = page_address(src_page) + src_offset; + dst_virt = page_address(dst_page) + dst_offset; + if (src_virt != dst_virt) { + memcpy(dst_virt, src_virt, len); + if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE) + __scatterwalk_flush_dcache_pages( + dst_page, dst_offset, len); + } /* Else, it's the same memory. No action needed. */ + } + nbytes -= len; + if (nbytes == 0) /* No more to copy? */ + break; - skcipher_walk_first(&walk, true); - do { - if (walk.src.virt.addr != walk.dst.virt.addr) - memcpy(walk.dst.virt.addr, walk.src.virt.addr, - walk.nbytes); - skcipher_walk_done(&walk, 0); - } while (walk.nbytes); + /* + * There's more to copy. Advance the offsets by the length + * copied this step, and advance the sg entries as needed. + */ + src_offset += len; + if (src_offset >= src->offset + src->length) { + src = sg_next(src); + src_offset = src->offset; + } + dst_offset += len; + if (dst_offset >= dst->offset + dst->length) { + dst = sg_next(dst); + dst_offset = dst->offset; + } + } } EXPORT_SYMBOL_GPL(memcpy_sglist); struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2], struct scatterlist *src, diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h index 83d14376ff2b..f485454e3955 100644 --- a/include/crypto/scatterwalk.h +++ b/include/crypto/scatterwalk.h @@ -225,10 +225,38 @@ static inline void scatterwalk_done_src(struct scatter_walk *walk, { scatterwalk_unmap(walk); scatterwalk_advance(walk, nbytes); } +/* + * Flush the dcache of any pages that overlap the region + * [offset, offset + nbytes) relative to base_page. + * + * This should be called only when ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, to ensure + * that all relevant code (including the call to sg_page() in the caller, if + * applicable) gets fully optimized out when !ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE. + */ +static inline void __scatterwalk_flush_dcache_pages(struct page *base_page, + unsigned int offset, + unsigned int nbytes) +{ + unsigned int num_pages; + + base_page += offset / PAGE_SIZE; + offset %= PAGE_SIZE; + + /* + * This is an overflow-safe version of + * num_pages = DIV_ROUND_UP(offset + nbytes, PAGE_SIZE). + */ + num_pages = nbytes / PAGE_SIZE; + num_pages += DIV_ROUND_UP(offset + (nbytes % PAGE_SIZE), PAGE_SIZE); + + for (unsigned int i = 0; i < num_pages; i++) + flush_dcache_page(base_page + i); +} + /** * scatterwalk_done_dst() - Finish one step of a walk of destination scatterlist * @walk: the scatter_walk * @nbytes: the number of bytes processed this step, less than or equal to the * number of bytes that scatterwalk_next() returned. @@ -238,31 +266,13 @@ static inline void scatterwalk_done_src(struct scatter_walk *walk, */ static inline void scatterwalk_done_dst(struct scatter_walk *walk, unsigned int nbytes) { scatterwalk_unmap(walk); - /* - * Explicitly check ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE instead of just - * relying on flush_dcache_page() being a no-op when not implemented, - * since otherwise the BUG_ON in sg_page() does not get optimized out. - * This also avoids having to consider whether the loop would get - * reliably optimized out or not. - */ - if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE) { - struct page *base_page; - unsigned int offset; - int start, end, i; - - base_page = sg_page(walk->sg); - offset = walk->offset; - start = offset >> PAGE_SHIFT; - end = start + (nbytes >> PAGE_SHIFT); - end += (offset_in_page(offset) + offset_in_page(nbytes) + - PAGE_SIZE - 1) >> PAGE_SHIFT; - for (i = start; i < end; i++) - flush_dcache_page(base_page + i); - } + if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE) + __scatterwalk_flush_dcache_pages(sg_page(walk->sg), + walk->offset, nbytes); scatterwalk_advance(walk, nbytes); } void scatterwalk_skip(struct scatter_walk *walk, unsigned int nbytes); -- 2.51.2

6 days, 10 hours

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[PATCH 1/2] crypto: scatterwalk - Fix memcpy_sglist() to always succeed

by Eric Biggers

The original implementation of memcpy_sglist() was broken because it didn't handle overlapping scatterlists. The current implementation is broken too because it calls the skcipher_walk functions which can fail. It ignores any errors from those functions. Fix it by replacing it with a new implementation written from scratch. It always succeeds. It's also a bit faster, since it avoids the overhead of skcipher_walk. skcipher_walk includes a lot of functionality (such as alignmask handling) that's irrelevant here. Reported-by: Colin Ian King <coking(a)nvidia.com> Closes: https://lore.kernel.org/r/20251114122620.111623-1-coking@nvidia.com Fixes: 131bdceca1f0 ("crypto: scatterwalk - Add memcpy_sglist") Fixes: 0f8d42bf128d ("crypto: scatterwalk - Move skcipher walk and use it for memcpy_sglist") Cc: stable(a)vger.kernel.org Signed-off-by: Eric Biggers <ebiggers(a)kernel.org> --- crypto/scatterwalk.c | 103 ++++++++++++++++++++++++++++++----- include/crypto/scatterwalk.h | 52 +++++++++++------- 2 files changed, 121 insertions(+), 34 deletions(-) diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c index 1d010e2a1b1a..af6c17bfcadb 100644 --- a/crypto/scatterwalk.c +++ b/crypto/scatterwalk.c @@ -99,30 +99,107 @@ void memcpy_to_sglist(struct scatterlist *sg, unsigned int start, scatterwalk_start_at_pos(&walk, sg, start); memcpy_to_scatterwalk(&walk, buf, nbytes); } EXPORT_SYMBOL_GPL(memcpy_to_sglist); +/** + * memcpy_sglist() - Copy data from one scatterlist to another + * @dst: The destination scatterlist. Can be NULL if @nbytes == 0. + * @src: The source scatterlist. Can be NULL if @nbytes == 0. + * @nbytes: Number of bytes to copy + * + * The scatterlists can overlap. Hence this really acts like memmove(), not + * memcpy(). + * + * Context: Any context + */ void memcpy_sglist(struct scatterlist *dst, struct scatterlist *src, unsigned int nbytes) { - struct skcipher_walk walk = {}; + unsigned int src_offset, dst_offset; - if (unlikely(nbytes == 0)) /* in case sg == NULL */ + if (unlikely(nbytes == 0)) /* in case src and/or dst is NULL */ return; - walk.total = nbytes; - - scatterwalk_start(&walk.in, src); - scatterwalk_start(&walk.out, dst); + src_offset = src->offset; + dst_offset = dst->offset; + for (;;) { + /* Compute the length to copy this step. */ + unsigned int len = min3(src->offset + src->length - src_offset, + dst->offset + dst->length - dst_offset, + nbytes); + struct page *src_page = sg_page(src); + struct page *dst_page = sg_page(dst); + const void *src_virt; + void *dst_virt; + + if (IS_ENABLED(CONFIG_HIGHMEM)) { + /* HIGHMEM: we may have to actually map the pages. */ + const unsigned int src_oip = offset_in_page(src_offset); + const unsigned int dst_oip = offset_in_page(dst_offset); + const unsigned int limit = PAGE_SIZE; + + /* Further limit len to not cross a page boundary. */ + len = min3(len, limit - src_oip, limit - dst_oip); + + /* Compute the source and destination pages. */ + src_page += src_offset / PAGE_SIZE; + dst_page += dst_offset / PAGE_SIZE; + + if (src_page != dst_page) { + /* + * Copy between different pages. + * No need for memmove(), as the pages differ. + */ + src_virt = kmap_local_page(src_page); + dst_virt = kmap_local_page(dst_page); + memcpy(dst_virt + dst_oip, src_virt + src_oip, + len); + flush_dcache_page(dst_page); + kunmap_local(dst_virt); + kunmap_local(src_virt); + } else if (src_oip != dst_oip) { + /* Copy between different parts of same page */ + dst_virt = kmap_local_page(dst_page); + memmove(dst_virt + dst_oip, dst_virt + src_oip, + len); + flush_dcache_page(dst_page); + kunmap_local(dst_virt); + } /* Exact overlap. No action needed. */ + } else { + /* + * !HIGHMEM: no mapping needed. Just work in the linear + * buffer of each sg entry. + */ + src_virt = page_address(src_page) + src_offset; + dst_virt = page_address(dst_page) + dst_offset; + if (src_virt != dst_virt) { + memmove(dst_virt, src_virt, len); + if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE) + __scatterwalk_flush_dcache_pages( + dst_page, dst_offset, len); + } + } + nbytes -= len; + if (nbytes == 0) /* No more to copy? */ + break; - skcipher_walk_first(&walk, true); - do { - if (walk.src.virt.addr != walk.dst.virt.addr) - memcpy(walk.dst.virt.addr, walk.src.virt.addr, - walk.nbytes); - skcipher_walk_done(&walk, 0); - } while (walk.nbytes); + /* + * There's more to copy. Advance the offsets by the length + * copied this step, and advance the sg entries as needed. + */ + src_offset += len; + if (src_offset >= src->offset + src->length) { + src = sg_next(src); + src_offset = src->offset; + } + dst_offset += len; + if (dst_offset >= dst->offset + dst->length) { + dst = sg_next(dst); + dst_offset = dst->offset; + } + } } EXPORT_SYMBOL_GPL(memcpy_sglist); struct scatterlist *scatterwalk_ffwd(struct scatterlist dst[2], struct scatterlist *src, diff --git a/include/crypto/scatterwalk.h b/include/crypto/scatterwalk.h index 83d14376ff2b..f485454e3955 100644 --- a/include/crypto/scatterwalk.h +++ b/include/crypto/scatterwalk.h @@ -225,10 +225,38 @@ static inline void scatterwalk_done_src(struct scatter_walk *walk, { scatterwalk_unmap(walk); scatterwalk_advance(walk, nbytes); } +/* + * Flush the dcache of any pages that overlap the region + * [offset, offset + nbytes) relative to base_page. + * + * This should be called only when ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, to ensure + * that all relevant code (including the call to sg_page() in the caller, if + * applicable) gets fully optimized out when !ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE. + */ +static inline void __scatterwalk_flush_dcache_pages(struct page *base_page, + unsigned int offset, + unsigned int nbytes) +{ + unsigned int num_pages; + + base_page += offset / PAGE_SIZE; + offset %= PAGE_SIZE; + + /* + * This is an overflow-safe version of + * num_pages = DIV_ROUND_UP(offset + nbytes, PAGE_SIZE). + */ + num_pages = nbytes / PAGE_SIZE; + num_pages += DIV_ROUND_UP(offset + (nbytes % PAGE_SIZE), PAGE_SIZE); + + for (unsigned int i = 0; i < num_pages; i++) + flush_dcache_page(base_page + i); +} + /** * scatterwalk_done_dst() - Finish one step of a walk of destination scatterlist * @walk: the scatter_walk * @nbytes: the number of bytes processed this step, less than or equal to the * number of bytes that scatterwalk_next() returned. @@ -238,31 +266,13 @@ static inline void scatterwalk_done_src(struct scatter_walk *walk, */ static inline void scatterwalk_done_dst(struct scatter_walk *walk, unsigned int nbytes) { scatterwalk_unmap(walk); - /* - * Explicitly check ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE instead of just - * relying on flush_dcache_page() being a no-op when not implemented, - * since otherwise the BUG_ON in sg_page() does not get optimized out. - * This also avoids having to consider whether the loop would get - * reliably optimized out or not. - */ - if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE) { - struct page *base_page; - unsigned int offset; - int start, end, i; - - base_page = sg_page(walk->sg); - offset = walk->offset; - start = offset >> PAGE_SHIFT; - end = start + (nbytes >> PAGE_SHIFT); - end += (offset_in_page(offset) + offset_in_page(nbytes) + - PAGE_SIZE - 1) >> PAGE_SHIFT; - for (i = start; i < end; i++) - flush_dcache_page(base_page + i); - } + if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE) + __scatterwalk_flush_dcache_pages(sg_page(walk->sg), + walk->offset, nbytes); scatterwalk_advance(walk, nbytes); } void scatterwalk_skip(struct scatter_walk *walk, unsigned int nbytes); -- 2.51.2

6 days, 10 hours

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[merged mm-hotfixes-stable] mm-swap-fix-potential-uaf-issue-for-vma-readahead.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm, swap: fix potential UAF issue for VMA readahead has been removed from the -mm tree. Its filename was mm-swap-fix-potential-uaf-issue-for-vma-readahead.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Kairui Song <kasong(a)tencent.com> Subject: mm, swap: fix potential UAF issue for VMA readahead Date: Tue, 11 Nov 2025 21:36:08 +0800 Since commit 78524b05f1a3 ("mm, swap: avoid redundant swap device pinning"), the common helper for allocating and preparing a folio in the swap cache layer no longer tries to get a swap device reference internally, because all callers of __read_swap_cache_async are already holding a swap entry reference. The repeated swap device pinning isn't needed on the same swap device. Caller of VMA readahead is also holding a reference to the target entry's swap device, but VMA readahead walks the page table, so it might encounter swap entries from other devices, and call __read_swap_cache_async on another device without holding a reference to it. So it is possible to cause a UAF when swapoff of device A raced with swapin on device B, and VMA readahead tries to read swap entries from device A. It's not easy to trigger, but in theory, it could cause real issues. Make VMA readahead try to get the device reference first if the swap device is a different one from the target entry. Link: https://lkml.kernel.org/r/20251111-swap-fix-vma-uaf-v1-1-41c660e58562@tence… Fixes: 78524b05f1a3 ("mm, swap: avoid redundant swap device pinning") Suggested-by: Huang Ying <ying.huang(a)linux.alibaba.com> Signed-off-by: Kairui Song <kasong(a)tencent.com> Acked-by: Chris Li <chrisl(a)kernel.org> Cc: Baoquan He <bhe(a)redhat.com> Cc: Barry Song <baohua(a)kernel.org> Cc: Kemeng Shi <shikemeng(a)huaweicloud.com> Cc: Nhat Pham <nphamcs(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/swap_state.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) --- a/mm/swap_state.c~mm-swap-fix-potential-uaf-issue-for-vma-readahead +++ a/mm/swap_state.c @@ -748,6 +748,8 @@ static struct folio *swap_vma_readahead( blk_start_plug(&plug); for (addr = start; addr < end; ilx++, addr += PAGE_SIZE) { + struct swap_info_struct *si = NULL; + if (!pte++) { pte = pte_offset_map(vmf->pmd, addr); if (!pte) @@ -761,8 +763,19 @@ static struct folio *swap_vma_readahead( continue; pte_unmap(pte); pte = NULL; + /* + * Readahead entry may come from a device that we are not + * holding a reference to, try to grab a reference, or skip. + */ + if (swp_type(entry) != swp_type(targ_entry)) { + si = get_swap_device(entry); + if (!si) + continue; + } folio = __read_swap_cache_async(entry, gfp_mask, mpol, ilx, &page_allocated, false); + if (si) + put_swap_device(si); if (!folio) continue; if (page_allocated) { _ Patches currently in -mm which might be from kasong(a)tencent.com are mm-swap-do-not-perform-synchronous-discard-during-allocation.patch mm-swap-rename-helper-for-setup-bad-slots.patch mm-swap-cleanup-swap-entry-allocation-parameter.patch mm-migrate-swap-drop-usage-of-folio_index.patch mm-swap-remove-redundant-argument-for-isolating-a-cluster.patch

6 days, 14 hours

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[merged mm-hotfixes-stable] selftests-user_events-fix-type-cast-for-write_index-packed-member-in-perf_test.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: selftests/user_events: fix type cast for write_index packed member in perf_test has been removed from the -mm tree. Its filename was selftests-user_events-fix-type-cast-for-write_index-packed-member-in-perf_test.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Ankit Khushwaha <ankitkhushwaha.linux(a)gmail.com> Subject: selftests/user_events: fix type cast for write_index packed member in perf_test Date: Thu, 6 Nov 2025 15:25:32 +0530 Accessing 'reg.write_index' directly triggers a -Waddress-of-packed-member warning due to potential unaligned pointer access: perf_test.c:239:38: warning: taking address of packed member 'write_index' of class or structure 'user_reg' may result in an unaligned pointer value [-Waddress-of-packed-member] 239 | ASSERT_NE(-1, write(self->data_fd, &reg.write_index, | ^~~~~~~~~~~~~~~ Since write(2) works with any alignment. Casting '&reg.write_index' explicitly to 'void *' to suppress this warning. Link: https://lkml.kernel.org/r/20251106095532.15185-1-ankitkhushwaha.linux@gmail… Fixes: 42187bdc3ca4 ("selftests/user_events: Add perf self-test for empty arguments events") Signed-off-by: Ankit Khushwaha <ankitkhushwaha.linux(a)gmail.com> Cc: Beau Belgrave <beaub(a)linux.microsoft.com> Cc: "Masami Hiramatsu (Google)" <mhiramat(a)kernel.org> Cc: Steven Rostedt <rostedt(a)goodmis.org> Cc: sunliming <sunliming(a)kylinos.cn> Cc: Wei Yang <richard.weiyang(a)gmail.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- tools/testing/selftests/user_events/perf_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/testing/selftests/user_events/perf_test.c~selftests-user_events-fix-type-cast-for-write_index-packed-member-in-perf_test +++ a/tools/testing/selftests/user_events/perf_test.c @@ -236,7 +236,7 @@ TEST_F(user, perf_empty_events) { ASSERT_EQ(1 << reg.enable_bit, self->check); /* Ensure write shows up at correct offset */ - ASSERT_NE(-1, write(self->data_fd, &reg.write_index, + ASSERT_NE(-1, write(self->data_fd, (void *)&reg.write_index, sizeof(reg.write_index))); val = (void *)(((char *)perf_page) + perf_page->data_offset); ASSERT_EQ(PERF_RECORD_SAMPLE, *val); _ Patches currently in -mm which might be from ankitkhushwaha.linux(a)gmail.com are selftest-mm-fix-pointer-comparison-in-mremap_test.patch

6 days, 14 hours

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[merged mm-hotfixes-stable] lib-test_kho-check-if-kho-is-enabled.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: lib/test_kho: check if KHO is enabled has been removed from the -mm tree. Its filename was lib-test_kho-check-if-kho-is-enabled.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Pasha Tatashin <pasha.tatashin(a)soleen.com> Subject: lib/test_kho: check if KHO is enabled Date: Thu, 6 Nov 2025 17:06:35 -0500 We must check whether KHO is enabled prior to issuing KHO commands, otherwise KHO internal data structures are not initialized. Link: https://lkml.kernel.org/r/20251106220635.2608494-1-pasha.tatashin@soleen.com Fixes: b753522bed0b ("kho: add test for kexec handover") Signed-off-by: Pasha Tatashin <pasha.tatashin(a)soleen.com> Reported-by: kernel test robot <oliver.sang(a)intel.com> Closes: https://lore.kernel.org/oe-lkp/202511061629.e242724-lkp@intel.com Reviewed-by: Pratyush Yadav <pratyush(a)kernel.org> Reviewed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org> Cc: Alexander Graf <graf(a)amazon.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- lib/test_kho.c | 3 +++ 1 file changed, 3 insertions(+) --- a/lib/test_kho.c~lib-test_kho-check-if-kho-is-enabled +++ a/lib/test_kho.c @@ -301,6 +301,9 @@ static int __init kho_test_init(void) phys_addr_t fdt_phys; int err; + if (!kho_is_enabled()) + return 0; + err = kho_retrieve_subtree(KHO_TEST_FDT, &fdt_phys); if (!err) return kho_test_restore(fdt_phys); _ Patches currently in -mm which might be from pasha.tatashin(a)soleen.com are kho-make-debugfs-interface-optional.patch kho-add-interfaces-to-unpreserve-folios-page-ranges-and-vmalloc.patch memblock-unpreserve-memory-in-case-of-error.patch test_kho-unpreserve-memory-in-case-of-error.patch kho-dont-unpreserve-memory-during-abort.patch liveupdate-kho-move-to-kernel-liveupdate.patch liveupdate-kho-move-to-kernel-liveupdate-fix.patch maintainers-update-kho-maintainers.patch kho-fix-misleading-log-message-in-kho_populate.patch kho-convert-__kho_abort-to-return-void.patch kho-introduce-high-level-memory-allocation-api.patch kho-preserve-fdt-folio-only-once-during-initialization.patch kho-verify-deserialization-status-and-fix-fdt-alignment-access.patch kho-always-expose-output-fdt-in-debugfs.patch kho-simplify-serialization-and-remove-__kho_abort.patch kho-remove-global-preserved_mem_map-and-store-state-in-fdt.patch kho-remove-abort-functionality-and-support-state-refresh.patch kho-update-fdt-dynamically-for-subtree-addition-removal.patch kho-allow-kexec-load-before-kho-finalization.patch kho-allow-memory-preservation-state-updates-after-finalization.patch kho-add-kconfig-option-to-enable-kho-by-default.patch liveupdate-luo_core-luo_ioctl-live-update-orchestrator.patch liveupdate-luo_core-integrate-with-kho.patch liveupdate-luo_core-integrate-with-kho-fix.patch reboot-call-liveupdate_reboot-before-kexec.patch liveupdate-luo_session-add-sessions-support.patch liveupdate-luo_session-add-sessions-support-fix.patch liveupdate-luo_ioctl-add-user-interface.patch liveupdate-luo_file-implement-file-systems-callbacks.patch liveupdate-luo_session-add-ioctls-for-file-preservation-and-state-management.patch liveupdate-luo_flb-introduce-file-lifecycle-bound-global-state.patch docs-add-luo-documentation.patch maintainers-add-liveupdate-entry.patch mm-memfd_luo-allow-preserving-memfd-fix.patch selftests-liveupdate-add-userspace-api-selftests.patch selftests-liveupdate-add-kexec-based-selftest-for-session-lifecycle.patch selftests-liveupdate-add-kexec-test-for-multiple-and-empty-sessions.patch tests-liveupdate-add-in-kernel-liveupdate-test.patch

6 days, 14 hours

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[merged mm-hotfixes-stable] mm-huge_memory-fix-folio-split-check-for-anon-folios-in-swapcache.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/huge_memory: fix folio split check for anon folios in swapcache has been removed from the -mm tree. Its filename was mm-huge_memory-fix-folio-split-check-for-anon-folios-in-swapcache.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Zi Yan <ziy(a)nvidia.com> Subject: mm/huge_memory: fix folio split check for anon folios in swapcache Date: Wed, 5 Nov 2025 11:29:10 -0500 Both uniform and non uniform split check missed the check to prevent splitting anon folios in swapcache to non-zero order. Splitting anon folios in swapcache to non-zero order can cause data corruption since swapcache only support PMD order and order-0 entries. This can happen when one use split_huge_pages under debugfs to split anon folios in swapcache. In-tree callers do not perform such an illegal operation. Only debugfs interface could trigger it. I will put adding a test case on my TODO list. Fix the check. Link: https://lkml.kernel.org/r/20251105162910.752266-1-ziy@nvidia.com Fixes: 58729c04cf10 ("mm/huge_memory: add buddy allocator like (non-uniform) folio_split()") Signed-off-by: Zi Yan <ziy(a)nvidia.com> Reported-by: "David Hildenbrand (Red Hat)" <david(a)kernel.org> Closes: https://lore.kernel.org/all/dc0ecc2c-4089-484f-917f-920fdca4c898@kernel.org/ Acked-by: David Hildenbrand (Red Hat) <david(a)kernel.org> Cc: Baolin Wang <baolin.wang(a)linux.alibaba.com> Cc: Barry Song <baohua(a)kernel.org> Cc: Dev Jain <dev.jain(a)arm.com> Cc: Lance Yang <lance.yang(a)linux.dev> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Nico Pache <npache(a)redhat.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Wei Yang <richard.weiyang(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/huge_memory.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/mm/huge_memory.c~mm-huge_memory-fix-folio-split-check-for-anon-folios-in-swapcache +++ a/mm/huge_memory.c @@ -3522,7 +3522,8 @@ bool non_uniform_split_supported(struct /* order-1 is not supported for anonymous THP. */ VM_WARN_ONCE(warns && new_order == 1, "Cannot split to order-1 folio"); - return new_order != 1; + if (new_order == 1) + return false; } else if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !mapping_large_folio_support(folio->mapping)) { /* @@ -3553,7 +3554,8 @@ bool uniform_split_supported(struct foli if (folio_test_anon(folio)) { VM_WARN_ONCE(warns && new_order == 1, "Cannot split to order-1 folio"); - return new_order != 1; + if (new_order == 1) + return false; } else if (new_order) { if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !mapping_large_folio_support(folio->mapping)) { _ Patches currently in -mm which might be from ziy(a)nvidia.com are mm-huge_memory-add-split_huge_page_to_order.patch mm-memory-failure-improve-large-block-size-folio-handling.patch mm-huge_memory-fix-kernel-doc-comments-for-folio_split-and-related.patch mm-huge_memory-fix-kernel-doc-comments-for-folio_split-and-related-fix.patch mm-huge_memory-fix-kernel-doc-comments-for-folio_split-and-related-fix-2.patch migrate-optimise-alloc_migration_target-fix.patch

6 days, 14 hours

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[merged mm-hotfixes-stable] crash-fix-crashkernel-resource-shrink.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: crash: fix crashkernel resource shrink has been removed from the -mm tree. Its filename was crash-fix-crashkernel-resource-shrink.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Sourabh Jain <sourabhjain(a)linux.ibm.com> Subject: crash: fix crashkernel resource shrink Date: Sun, 2 Nov 2025 01:07:41 +0530 When crashkernel is configured with a high reservation, shrinking its value below the low crashkernel reservation causes two issues: 1. Invalid crashkernel resource objects 2. Kernel crash if crashkernel shrinking is done twice For example, with crashkernel=200M,high, the kernel reserves 200MB of high memory and some default low memory (say 256MB). The reservation appears as: cat /proc/iomem | grep -i crash af000000-beffffff : Crash kernel 433000000-43f7fffff : Crash kernel If crashkernel is then shrunk to 50MB (echo 52428800 > /sys/kernel/kexec_crash_size), /proc/iomem still shows 256MB reserved: af000000-beffffff : Crash kernel Instead, it should show 50MB: af000000-b21fffff : Crash kernel Further shrinking crashkernel to 40MB causes a kernel crash with the following trace (x86): BUG: kernel NULL pointer dereference, address: 0000000000000038 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI <snip...> Call Trace: <TASK> ? __die_body.cold+0x19/0x27 ? page_fault_oops+0x15a/0x2f0 ? search_module_extables+0x19/0x60 ? search_bpf_extables+0x5f/0x80 ? exc_page_fault+0x7e/0x180 ? asm_exc_page_fault+0x26/0x30 ? __release_resource+0xd/0xb0 release_resource+0x26/0x40 __crash_shrink_memory+0xe5/0x110 crash_shrink_memory+0x12a/0x190 kexec_crash_size_store+0x41/0x80 kernfs_fop_write_iter+0x141/0x1f0 vfs_write+0x294/0x460 ksys_write+0x6d/0xf0 <snip...> This happens because __crash_shrink_memory()/kernel/crash_core.c incorrectly updates the crashk_res resource object even when crashk_low_res should be updated. Fix this by ensuring the correct crashkernel resource object is updated when shrinking crashkernel memory. Link: https://lkml.kernel.org/r/20251101193741.289252-1-sourabhjain@linux.ibm.com Fixes: 16c6006af4d4 ("kexec: enable kexec_crash_size to support two crash kernel regions") Signed-off-by: Sourabh Jain <sourabhjain(a)linux.ibm.com> Acked-by: Baoquan He <bhe(a)redhat.com> Cc: Zhen Lei <thunder.leizhen(a)huawei.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- kernel/crash_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/crash_core.c~crash-fix-crashkernel-resource-shrink +++ a/kernel/crash_core.c @@ -373,7 +373,7 @@ static int __crash_shrink_memory(struct old_res->start = 0; old_res->end = 0; } else { - crashk_res.end = ram_res->start - 1; + old_res->end = ram_res->start - 1; } crash_free_reserved_phys_range(ram_res->start, ram_res->end); _ Patches currently in -mm which might be from sourabhjain(a)linux.ibm.com are

6 days, 14 hours

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