October 2023 - Linux-stable-mirror

[merged mm-stable] mm-make-pr_mdwe_refuse_exec_gain-an-unsigned-long.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: make PR_MDWE_REFUSE_EXEC_GAIN an unsigned long has been removed from the -mm tree. Its filename was mm-make-pr_mdwe_refuse_exec_gain-an-unsigned-long.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Florent Revest <revest(a)chromium.org> Subject: mm: make PR_MDWE_REFUSE_EXEC_GAIN an unsigned long Date: Mon, 28 Aug 2023 17:08:56 +0200 Defining a prctl flag as an int is a footgun because on a 64 bit machine and with a variadic implementation of prctl (like in musl and glibc), when used directly as a prctl argument, it can get casted to long with garbage upper bits which would result in unexpected behaviors. This patch changes the constant to an unsigned long to eliminate that possibilities. This does not break UAPI. I think that a stable backport would be "nice to have": to reduce the chances that users build binaries that could end up with garbage bits in their MDWE prctl arguments. We are not aware of anyone having yet encountered this corner case with MDWE prctls but a backport would reduce the likelihood it happens, since this sort of issues has happened with other prctls. But If this is perceived as a backporting burden, I suppose we could also live without a stable backport. Link: https://lkml.kernel.org/r/20230828150858.393570-5-revest@chromium.org Fixes: b507808ebce2 ("mm: implement memory-deny-write-execute as a prctl") Signed-off-by: Florent Revest <revest(a)chromium.org> Suggested-by: Alexey Izbyshev <izbyshev(a)ispras.ru> Reviewed-by: David Hildenbrand <david(a)redhat.com> Reviewed-by: Kees Cook <keescook(a)chromium.org> Acked-by: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Anshuman Khandual <anshuman.khandual(a)arm.com> Cc: Ayush Jain <ayush.jain3(a)amd.com> Cc: Greg Thelen <gthelen(a)google.com> Cc: Joey Gouly <joey.gouly(a)arm.com> Cc: KP Singh <kpsingh(a)kernel.org> Cc: Mark Brown <broonie(a)kernel.org> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Peter Xu <peterx(a)redhat.com> Cc: Ryan Roberts <ryan.roberts(a)arm.com> Cc: Szabolcs Nagy <Szabolcs.Nagy(a)arm.com> Cc: Topi Miettinen <toiwoton(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/uapi/linux/prctl.h | 2 +- tools/include/uapi/linux/prctl.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/include/uapi/linux/prctl.h~mm-make-pr_mdwe_refuse_exec_gain-an-unsigned-long +++ a/include/uapi/linux/prctl.h @@ -283,7 +283,7 @@ struct prctl_mm_map { /* Memory deny write / execute */ #define PR_SET_MDWE 65 -# define PR_MDWE_REFUSE_EXEC_GAIN 1 +# define PR_MDWE_REFUSE_EXEC_GAIN (1UL << 0) #define PR_GET_MDWE 66 --- a/tools/include/uapi/linux/prctl.h~mm-make-pr_mdwe_refuse_exec_gain-an-unsigned-long +++ a/tools/include/uapi/linux/prctl.h @@ -283,7 +283,7 @@ struct prctl_mm_map { /* Memory deny write / execute */ #define PR_SET_MDWE 65 -# define PR_MDWE_REFUSE_EXEC_GAIN 1 +# define PR_MDWE_REFUSE_EXEC_GAIN (1UL << 0) #define PR_GET_MDWE 66 _ Patches currently in -mm which might be from revest(a)chromium.org are

1 year, 3 months

1
0
0 0

[merged mm-hotfixes-stable] mm-migrate-fix-do_pages_move-for-compat-pointers.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/migrate: fix do_pages_move for compat pointers has been removed from the -mm tree. Its filename was mm-migrate-fix-do_pages_move-for-compat-pointers.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: Gregory Price <gourry.memverge(a)gmail.com> Subject: mm/migrate: fix do_pages_move for compat pointers Date: Tue, 3 Oct 2023 10:48:56 -0400 do_pages_move does not handle compat pointers for the page list. correctly. Add in_compat_syscall check and appropriate get_user fetch when iterating the page list. It makes the syscall in compat mode (32-bit userspace, 64-bit kernel) work the same way as the native 32-bit syscall again, restoring the behavior before my broken commit 5b1b561ba73c ("mm: simplify compat_sys_move_pages"). More specifically, my patch moved the parsing of the 'pages' array from the main entry point into do_pages_stat(), which left the syscall working correctly for the 'stat' operation (nodes = NULL), while the 'move' operation (nodes != NULL) is now missing the conversion and interprets 'pages' as an array of 64-bit pointers instead of the intended 32-bit userspace pointers. It is possible that nobody noticed this bug because the few applications that actually call move_pages are unlikely to run in compat mode because of their large memory requirements, but this clearly fixes a user-visible regression and should have been caught by ltp. Link: https://lkml.kernel.org/r/20231003144857.752952-1-gregory.price@memverge.com Fixes: 5b1b561ba73c ("mm: simplify compat_sys_move_pages") Signed-off-by: Gregory Price <gregory.price(a)memverge.com> Reported-by: Arnd Bergmann <arnd(a)arndb.de> Co-developed-by: Arnd Bergmann <arnd(a)arndb.de> Cc: Jonathan Cameron <Jonathan.Cameron(a)huawei.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/migrate.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) --- a/mm/migrate.c~mm-migrate-fix-do_pages_move-for-compat-pointers +++ a/mm/migrate.c @@ -2162,6 +2162,7 @@ static int do_pages_move(struct mm_struc const int __user *nodes, int __user *status, int flags) { + compat_uptr_t __user *compat_pages = (void __user *)pages; int current_node = NUMA_NO_NODE; LIST_HEAD(pagelist); int start, i; @@ -2174,8 +2175,17 @@ static int do_pages_move(struct mm_struc int node; err = -EFAULT; - if (get_user(p, pages + i)) - goto out_flush; + if (in_compat_syscall()) { + compat_uptr_t cp; + + if (get_user(cp, compat_pages + i)) + goto out_flush; + + p = compat_ptr(cp); + } else { + if (get_user(p, pages + i)) + goto out_flush; + } if (get_user(node, nodes + i)) goto out_flush; _ Patches currently in -mm which might be from gourry.memverge(a)gmail.com are mm-migrate-remove-unused-mm-argument-from-do_move_pages_to_node.patch

1 year, 3 months

1
0
0 0

[merged mm-hotfixes-stable] mm-mempolicy-fix-set_mempolicy_home_node-previous-vma-pointer.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/mempolicy: fix set_mempolicy_home_node() previous VMA pointer has been removed from the -mm tree. Its filename was mm-mempolicy-fix-set_mempolicy_home_node-previous-vma-pointer.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: "Liam R. Howlett" <Liam.Howlett(a)oracle.com> Subject: mm/mempolicy: fix set_mempolicy_home_node() previous VMA pointer Date: Thu, 28 Sep 2023 13:24:32 -0400 The two users of mbind_range() are expecting that mbind_range() will update the pointer to the previous VMA, or return an error. However, set_mempolicy_home_node() does not call mbind_range() if there is no VMA policy. The fix is to update the pointer to the previous VMA prior to continuing iterating the VMAs when there is no policy. Users may experience a WARN_ON() during VMA policy updates when updating a range of VMAs on the home node. Link: https://lkml.kernel.org/r/20230928172432.2246534-1-Liam.Howlett@oracle.com Link: https://lore.kernel.org/linux-mm/CALcu4rbT+fMVNaO_F2izaCT+e7jzcAciFkOvk21HG… Fixes: f4e9e0e69468 ("mm/mempolicy: fix use-after-free of VMA iterator") Signed-off-by: Liam R. Howlett <Liam.Howlett(a)oracle.com> Reported-by: Yikebaer Aizezi <yikebaer61(a)gmail.com> Closes: https://lore.kernel.org/linux-mm/CALcu4rbT+fMVNaO_F2izaCT+e7jzcAciFkOvk21HG… Reviewed-by: Lorenzo Stoakes <lstoakes(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/mempolicy.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/mm/mempolicy.c~mm-mempolicy-fix-set_mempolicy_home_node-previous-vma-pointer +++ a/mm/mempolicy.c @@ -1543,8 +1543,10 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, * the home node for vmas we already updated before. */ old = vma_policy(vma); - if (!old) + if (!old) { + prev = vma; continue; + } if (old->mode != MPOL_BIND && old->mode != MPOL_PREFERRED_MANY) { err = -EOPNOTSUPP; break; _ Patches currently in -mm which might be from Liam.Howlett(a)oracle.com are mmap-add-clarifying-comment-to-vma_merge-code.patch radix-tree-test-suite-fix-allocation-calculation-in-kmem_cache_alloc_bulk.patch

1 year, 3 months

1
0
0 0

[merged mm-hotfixes-stable] mmap-fix-error-paths-with-dup_anon_vma.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mmap: fix error paths with dup_anon_vma() has been removed from the -mm tree. Its filename was mmap-fix-error-paths-with-dup_anon_vma.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: "Liam R. Howlett" <Liam.Howlett(a)oracle.com> Subject: mmap: fix error paths with dup_anon_vma() Date: Fri, 29 Sep 2023 14:30:40 -0400 When the calling function fails after the dup_anon_vma(), the duplication of the anon_vma is not being undone. Add the necessary unlink_anon_vma() call to the error paths that are missing them. This issue showed up during inspection of the error path in vma_merge() for an unrelated vma iterator issue. Users may experience increased memory usage, which may be problematic as the failure would likely be caused by a low memory situation. Link: https://lkml.kernel.org/r/20230929183041.2835469-3-Liam.Howlett@oracle.com Fixes: d4af56c5c7c6 ("mm: start tracking VMAs with maple tree") Signed-off-by: Liam R. Howlett <Liam.Howlett(a)oracle.com> Reviewed-by: Lorenzo Stoakes <lstoakes(a)gmail.com> Acked-by: Vlastimil Babka <vbabka(a)suse.cz> Cc: Jann Horn <jannh(a)google.com> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/mmap.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) --- a/mm/mmap.c~mmap-fix-error-paths-with-dup_anon_vma +++ a/mm/mmap.c @@ -583,11 +583,12 @@ again: * dup_anon_vma() - Helper function to duplicate anon_vma * @dst: The destination VMA * @src: The source VMA + * @dup: Pointer to the destination VMA when successful. * * Returns: 0 on success. */ static inline int dup_anon_vma(struct vm_area_struct *dst, - struct vm_area_struct *src) + struct vm_area_struct *src, struct vm_area_struct **dup) { /* * Easily overlooked: when mprotect shifts the boundary, make sure the @@ -595,9 +596,15 @@ static inline int dup_anon_vma(struct vm * anon pages imported. */ if (src->anon_vma && !dst->anon_vma) { + int ret; + vma_assert_write_locked(dst); dst->anon_vma = src->anon_vma; - return anon_vma_clone(dst, src); + ret = anon_vma_clone(dst, src); + if (ret) + return ret; + + *dup = dst; } return 0; @@ -624,6 +631,7 @@ int vma_expand(struct vma_iterator *vmi, unsigned long start, unsigned long end, pgoff_t pgoff, struct vm_area_struct *next) { + struct vm_area_struct *anon_dup = NULL; bool remove_next = false; struct vma_prepare vp; @@ -633,7 +641,7 @@ int vma_expand(struct vma_iterator *vmi, remove_next = true; vma_start_write(next); - ret = dup_anon_vma(vma, next); + ret = dup_anon_vma(vma, next, &anon_dup); if (ret) return ret; } @@ -661,6 +669,8 @@ int vma_expand(struct vma_iterator *vmi, return 0; nomem: + if (anon_dup) + unlink_anon_vmas(anon_dup); return -ENOMEM; } @@ -860,6 +870,7 @@ struct vm_area_struct *vma_merge(struct { struct vm_area_struct *curr, *next, *res; struct vm_area_struct *vma, *adjust, *remove, *remove2; + struct vm_area_struct *anon_dup = NULL; struct vma_prepare vp; pgoff_t vma_pgoff; int err = 0; @@ -927,18 +938,18 @@ struct vm_area_struct *vma_merge(struct vma_start_write(next); remove = next; /* case 1 */ vma_end = next->vm_end; - err = dup_anon_vma(prev, next); + err = dup_anon_vma(prev, next, &anon_dup); if (curr) { /* case 6 */ vma_start_write(curr); remove = curr; remove2 = next; if (!next->anon_vma) - err = dup_anon_vma(prev, curr); + err = dup_anon_vma(prev, curr, &anon_dup); } } else if (merge_prev) { /* case 2 */ if (curr) { vma_start_write(curr); - err = dup_anon_vma(prev, curr); + err = dup_anon_vma(prev, curr, &anon_dup); if (end == curr->vm_end) { /* case 7 */ remove = curr; } else { /* case 5 */ @@ -954,7 +965,7 @@ struct vm_area_struct *vma_merge(struct vma_end = addr; adjust = next; adj_start = -(prev->vm_end - addr); - err = dup_anon_vma(next, prev); + err = dup_anon_vma(next, prev, &anon_dup); } else { /* * Note that cases 3 and 8 are the ONLY ones where prev @@ -968,7 +979,7 @@ struct vm_area_struct *vma_merge(struct vma_pgoff = curr->vm_pgoff; vma_start_write(curr); remove = curr; - err = dup_anon_vma(next, curr); + err = dup_anon_vma(next, curr, &anon_dup); } } } @@ -1018,6 +1029,9 @@ struct vm_area_struct *vma_merge(struct return res; prealloc_fail: + if (anon_dup) + unlink_anon_vmas(anon_dup); + anon_vma_fail: vma_iter_set(vmi, addr); vma_iter_load(vmi); _ Patches currently in -mm which might be from Liam.Howlett(a)oracle.com are mmap-add-clarifying-comment-to-vma_merge-code.patch radix-tree-test-suite-fix-allocation-calculation-in-kmem_cache_alloc_bulk.patch

1 year, 3 months

1
0
0 0

[merged mm-hotfixes-stable] mmap-fix-vma_iterator-in-error-path-of-vma_merge.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mmap: fix vma_iterator in error path of vma_merge() has been removed from the -mm tree. Its filename was mmap-fix-vma_iterator-in-error-path-of-vma_merge.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: "Liam R. Howlett" <Liam.Howlett(a)oracle.com> Subject: mmap: fix vma_iterator in error path of vma_merge() Date: Fri, 29 Sep 2023 14:30:39 -0400 During the error path, the vma iterator may not be correctly positioned or set to the correct range. Undo the vma_prev() call by resetting to the passed in address. Re-walking to the same range will fix the range to the area previously passed in. Users would notice increased cycles as vma_merge() would be called an extra time with vma == prev, and thus would fail to merge and return. Link: https://lore.kernel.org/linux-mm/CAG48ez12VN1JAOtTNMY+Y2YnsU45yL5giS-Qn=ejt… Link: https://lkml.kernel.org/r/20230929183041.2835469-2-Liam.Howlett@oracle.com Fixes: 18b098af2890 ("vma_merge: set vma iterator to correct position.") Signed-off-by: Liam R. Howlett <Liam.Howlett(a)oracle.com> Reported-by: Jann Horn <jannh(a)google.com> Closes: https://lore.kernel.org/linux-mm/CAG48ez12VN1JAOtTNMY+Y2YnsU45yL5giS-Qn=ejt… Reviewed-by: Lorenzo Stoakes <lstoakes(a)gmail.com> Acked-by: Vlastimil Babka <vbabka(a)suse.cz> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/mmap.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/mm/mmap.c~mmap-fix-vma_iterator-in-error-path-of-vma_merge +++ a/mm/mmap.c @@ -975,7 +975,7 @@ struct vm_area_struct *vma_merge(struct /* Error in anon_vma clone. */ if (err) - return NULL; + goto anon_vma_fail; if (vma_start < vma->vm_start || vma_end > vma->vm_end) vma_expanded = true; @@ -988,7 +988,7 @@ struct vm_area_struct *vma_merge(struct } if (vma_iter_prealloc(vmi, vma)) - return NULL; + goto prealloc_fail; init_multi_vma_prep(&vp, vma, adjust, remove, remove2); VM_WARN_ON(vp.anon_vma && adjust && adjust->anon_vma && @@ -1016,6 +1016,12 @@ struct vm_area_struct *vma_merge(struct vma_complete(&vp, vmi, mm); khugepaged_enter_vma(res, vm_flags); return res; + +prealloc_fail: +anon_vma_fail: + vma_iter_set(vmi, addr); + vma_iter_load(vmi); + return NULL; } /* _ Patches currently in -mm which might be from Liam.Howlett(a)oracle.com are mmap-add-clarifying-comment-to-vma_merge-code.patch radix-tree-test-suite-fix-allocation-calculation-in-kmem_cache_alloc_bulk.patch

1 year, 3 months

1
0
0 0

[merged mm-hotfixes-stable] mm-page_alloc-correct-start-page-when-guard-page-debug-is-enabled.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/page_alloc: correct start page when guard page debug is enabled has been removed from the -mm tree. Its filename was mm-page_alloc-correct-start-page-when-guard-page-debug-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: Kemeng Shi <shikemeng(a)huaweicloud.com> Subject: mm/page_alloc: correct start page when guard page debug is enabled Date: Wed, 27 Sep 2023 17:44:01 +0800 When guard page debug is enabled and set_page_guard returns success, we miss to forward page to point to start of next split range and we will do split unexpectedly in page range without target page. Move start page update before set_page_guard to fix this. As we split to wrong target page, then splited pages are not able to merge back to original order when target page is put back and splited pages except target page is not usable. To be specific: Consider target page is the third page in buddy page with order 2. | buddy-2 | Page | Target | Page | After break down to target page, we will only set first page to Guard because of bug. | Guard | Page | Target | Page | When we try put_page_back_buddy with target page, the buddy page of target if neither guard nor buddy, Then it's not able to construct original page with order 2 | Guard | Page | buddy-0 | Page | All pages except target page is not in free list and is not usable. Link: https://lkml.kernel.org/r/20230927094401.68205-1-shikemeng@huaweicloud.com Fixes: 06be6ff3d2ec ("mm,hwpoison: rework soft offline for free pages") Signed-off-by: Kemeng Shi <shikemeng(a)huaweicloud.com> Acked-by: Naoya Horiguchi <naoya.horiguchi(a)nec.com> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Oscar Salvador <osalvador(a)suse.de> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/page_alloc.c~mm-page_alloc-correct-start-page-when-guard-page-debug-is-enabled +++ a/mm/page_alloc.c @@ -6475,6 +6475,7 @@ static void break_down_buddy_pages(struc next_page = page; current_buddy = page + size; } + page = next_page; if (set_page_guard(zone, current_buddy, high, migratetype)) continue; @@ -6482,7 +6483,6 @@ static void break_down_buddy_pages(struc if (current_buddy != target) { add_to_free_list(current_buddy, zone, high, migratetype); set_buddy_order(current_buddy, high); - page = next_page; } } } _ Patches currently in -mm which might be from shikemeng(a)huaweicloud.com are mm-page_alloc-remove-unnecessary-check-in-break_down_buddy_pages.patch mm-page_alloc-remove-unnecessary-next_page-in-break_down_buddy_pages.patch

1 year, 3 months

1
0
0 0

[PATCH] mm: zswap: fix pool refcount bug around shrink_worker()

by Johannes Weiner

When a zswap store fails due to the limit, it acquires a pool reference and queues the shrinker. When the shrinker runs, it drops the reference. However, there can be multiple store attempts before the shrinker wakes up and runs once. This results in reference leaks and eventual saturation warnings for the pool refcount. Fix this by dropping the reference again when the shrinker is already queued. This ensures one reference per shrinker run. Reported-by: Chris Mason <clm(a)fb.com> Fixes: 45190f01dd40 ("mm/zswap.c: add allocation hysteresis if pool limit is hit") Cc: stable(a)vger.kernel.org [5.6+] Cc: Vitaly Wool <vitaly.wool(a)konsulko.com> Cc: Domenico Cerasuolo <cerasuolodomenico(a)gmail.com> Cc: Nhat Pham <nphamcs(a)gmail.com> Signed-off-by: Johannes Weiner <hannes(a)cmpxchg.org> --- mm/zswap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 083c693602b8..37d2b1cb2ecb 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1383,8 +1383,8 @@ bool zswap_store(struct folio *folio) shrink: pool = zswap_pool_last_get(); - if (pool) - queue_work(shrink_wq, &pool->shrink_work); + if (pool && !queue_work(shrink_wq, &pool->shrink_work)) + zswap_pool_put(pool); goto reject; } -- 2.42.0

1 year, 3 months

2
1
0 0

[PATCH v3 2/3] mmap: Fix error paths with dup_anon_vma()

by Liam R. Howlett

When the calling function fails after the dup_anon_vma(), the duplication of the anon_vma is not being undone. Add the necessary unlink_anon_vma() call to the error paths that are missing them. This issue showed up during inspection of the error path in vma_merge() for an unrelated vma iterator issue. Users may experience increased memory usage, which may be problematic as the failure would likely be caused by a low memory situation. Fixes: d4af56c5c7c6 ("mm: start tracking VMAs with maple tree") Cc: stable(a)vger.kernel.org Cc: Jann Horn <jannh(a)google.com> Signed-off-by: Liam R. Howlett <Liam.Howlett(a)oracle.com> --- mm/mmap.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index acb7dea49e23..f9f0a5fe4db4 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -583,11 +583,12 @@ static inline void vma_complete(struct vma_prepare *vp, * dup_anon_vma() - Helper function to duplicate anon_vma * @dst: The destination VMA * @src: The source VMA + * @dup: Pointer to the destination VMA when successful. * * Returns: 0 on success. */ static inline int dup_anon_vma(struct vm_area_struct *dst, - struct vm_area_struct *src) + struct vm_area_struct *src, struct vm_area_struct **dup) { /* * Easily overlooked: when mprotect shifts the boundary, make sure the @@ -595,9 +596,15 @@ static inline int dup_anon_vma(struct vm_area_struct *dst, * anon pages imported. */ if (src->anon_vma && !dst->anon_vma) { + int ret; + vma_assert_write_locked(dst); dst->anon_vma = src->anon_vma; - return anon_vma_clone(dst, src); + ret = anon_vma_clone(dst, src); + if (ret) + return ret; + + *dup = dst; } return 0; @@ -624,6 +631,7 @@ int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma, unsigned long start, unsigned long end, pgoff_t pgoff, struct vm_area_struct *next) { + struct vm_area_struct *anon_dup = NULL; bool remove_next = false; struct vma_prepare vp; @@ -633,7 +641,7 @@ int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma, remove_next = true; vma_start_write(next); - ret = dup_anon_vma(vma, next); + ret = dup_anon_vma(vma, next, &anon_dup); if (ret) return ret; } @@ -661,6 +669,8 @@ int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma, return 0; nomem: + if (anon_dup) + unlink_anon_vmas(anon_dup); return -ENOMEM; } @@ -860,6 +870,7 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, { struct vm_area_struct *curr, *next, *res; struct vm_area_struct *vma, *adjust, *remove, *remove2; + struct vm_area_struct *anon_dup = NULL; struct vma_prepare vp; pgoff_t vma_pgoff; int err = 0; @@ -927,18 +938,18 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, vma_start_write(next); remove = next; /* case 1 */ vma_end = next->vm_end; - err = dup_anon_vma(prev, next); + err = dup_anon_vma(prev, next, &anon_dup); if (curr) { /* case 6 */ vma_start_write(curr); remove = curr; remove2 = next; if (!next->anon_vma) - err = dup_anon_vma(prev, curr); + err = dup_anon_vma(prev, curr, &anon_dup); } } else if (merge_prev) { /* case 2 */ if (curr) { vma_start_write(curr); - err = dup_anon_vma(prev, curr); + err = dup_anon_vma(prev, curr, &anon_dup); if (end == curr->vm_end) { /* case 7 */ remove = curr; } else { /* case 5 */ @@ -954,7 +965,7 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, vma_end = addr; adjust = next; adj_start = -(prev->vm_end - addr); - err = dup_anon_vma(next, prev); + err = dup_anon_vma(next, prev, &anon_dup); } else { /* * Note that cases 3 and 8 are the ONLY ones where prev @@ -968,7 +979,7 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, vma_pgoff = curr->vm_pgoff; vma_start_write(curr); remove = curr; - err = dup_anon_vma(next, curr); + err = dup_anon_vma(next, curr, &anon_dup); } } } @@ -1018,6 +1029,9 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm, return res; prealloc_fail: + if (anon_dup) + unlink_anon_vmas(anon_dup); + anon_vma_fail: vma_iter_set(vmi, addr); vma_iter_load(vmi); -- 2.40.1

1 year, 3 months

6
10
0 0

+ hugetlbfs-close-race-between-madv_dontneed-and-page-fault.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: hugetlbfs: close race between MADV_DONTNEED and page fault has been added to the -mm mm-hotfixes-unstable branch. Its filename is hugetlbfs-close-race-between-madv_dontneed-and-page-fault.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: Rik van Riel <riel(a)surriel.com> Subject: hugetlbfs: close race between MADV_DONTNEED and page fault Date: Thu, 5 Oct 2023 23:59:08 -0400 Malloc libraries, like jemalloc and tcalloc, take decisions on when to call madvise independently from the code in the main application. This sometimes results in the application page faulting on an address, right after the malloc library has shot down the backing memory with MADV_DONTNEED. Usually this is harmless, because we always have some 4kB pages sitting around to satisfy a page fault. However, with hugetlbfs systems often allocate only the exact number of huge pages that the application wants. Due to TLB batching, hugetlbfs MADV_DONTNEED will free pages outside of any lock taken on the page fault path, which can open up the following race condition: CPU 1 CPU 2 MADV_DONTNEED unmap page shoot down TLB entry page fault fail to allocate a huge page killed with SIGBUS free page Fix that race by pulling the locking from __unmap_hugepage_final_range into helper functions called from zap_page_range_single. This ensures page faults stay locked out of the MADV_DONTNEED VMA until the huge pages have actually been freed. Link: https://lkml.kernel.org/r/20231006040020.3677377-4-riel@surriel.com Fixes: 04ada095dcfc ("hugetlb: don't delete vma_lock in hugetlb MADV_DONTNEED processing") Signed-off-by: Rik van Riel <riel(a)surriel.com> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Mike Kravetz <mike.kravetz(a)oracle.com> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/hugetlb.h | 35 +++++++++++++++++++++++++++++++++-- mm/hugetlb.c | 34 ++++++++++++++++++++++------------ mm/memory.c | 13 ++++++++----- 3 files changed, 63 insertions(+), 19 deletions(-) --- a/include/linux/hugetlb.h~hugetlbfs-close-race-between-madv_dontneed-and-page-fault +++ a/include/linux/hugetlb.h @@ -139,7 +139,7 @@ struct page *hugetlb_follow_page_mask(st void unmap_hugepage_range(struct vm_area_struct *, unsigned long, unsigned long, struct page *, zap_flags_t); -void __unmap_hugepage_range_final(struct mmu_gather *tlb, +void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long start, unsigned long end, struct page *ref_page, zap_flags_t zap_flags); @@ -246,6 +246,25 @@ int huge_pmd_unshare(struct mm_struct *m void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end); +extern void __hugetlb_zap_begin(struct vm_area_struct *vma, + unsigned long *begin, unsigned long *end); +extern void __hugetlb_zap_end(struct vm_area_struct *vma, + struct zap_details *details); + +static inline void hugetlb_zap_begin(struct vm_area_struct *vma, + unsigned long *start, unsigned long *end) +{ + if (is_vm_hugetlb_page(vma)) + __hugetlb_zap_begin(vma, start, end); +} + +static inline void hugetlb_zap_end(struct vm_area_struct *vma, + struct zap_details *details) +{ + if (is_vm_hugetlb_page(vma)) + __hugetlb_zap_end(vma, details); +} + void hugetlb_vma_lock_read(struct vm_area_struct *vma); void hugetlb_vma_unlock_read(struct vm_area_struct *vma); void hugetlb_vma_lock_write(struct vm_area_struct *vma); @@ -297,6 +316,18 @@ static inline void adjust_range_if_pmd_s { } +static inline void hugetlb_zap_begin( + struct vm_area_struct *vma, + unsigned long *start, unsigned long *end) +{ +} + +static inline void hugetlb_zap_end( + struct vm_area_struct *vma, + struct zap_details *details) +{ +} + static inline struct page *hugetlb_follow_page_mask( struct vm_area_struct *vma, unsigned long address, unsigned int flags, unsigned int *page_mask) @@ -442,7 +473,7 @@ static inline long hugetlb_change_protec return 0; } -static inline void __unmap_hugepage_range_final(struct mmu_gather *tlb, +static inline void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long start, unsigned long end, struct page *ref_page, zap_flags_t zap_flags) --- a/mm/hugetlb.c~hugetlbfs-close-race-between-madv_dontneed-and-page-fault +++ a/mm/hugetlb.c @@ -5306,9 +5306,9 @@ int move_hugetlb_page_tables(struct vm_a return len + old_addr - old_end; } -static void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, - unsigned long start, unsigned long end, - struct page *ref_page, zap_flags_t zap_flags) +void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long start, unsigned long end, + struct page *ref_page, zap_flags_t zap_flags) { struct mm_struct *mm = vma->vm_mm; unsigned long address; @@ -5437,16 +5437,25 @@ static void __unmap_hugepage_range(struc tlb_flush_mmu_tlbonly(tlb); } -void __unmap_hugepage_range_final(struct mmu_gather *tlb, - struct vm_area_struct *vma, unsigned long start, - unsigned long end, struct page *ref_page, - zap_flags_t zap_flags) +void __hugetlb_zap_begin(struct vm_area_struct *vma, + unsigned long *start, unsigned long *end) { + if (!vma->vm_file) /* hugetlbfs_file_mmap error */ + return; + + adjust_range_if_pmd_sharing_possible(vma, start, end); hugetlb_vma_lock_write(vma); - i_mmap_lock_write(vma->vm_file->f_mapping); + if (vma->vm_file) + i_mmap_lock_write(vma->vm_file->f_mapping); +} + +void __hugetlb_zap_end(struct vm_area_struct *vma, + struct zap_details *details) +{ + zap_flags_t zap_flags = details ? details->zap_flags : 0; - /* mmu notification performed in caller */ - __unmap_hugepage_range(tlb, vma, start, end, ref_page, zap_flags); + if (!vma->vm_file) /* hugetlbfs_file_mmap error */ + return; if (zap_flags & ZAP_FLAG_UNMAP) { /* final unmap */ /* @@ -5459,11 +5468,12 @@ void __unmap_hugepage_range_final(struct * someone else. */ __hugetlb_vma_unlock_write_free(vma); - i_mmap_unlock_write(vma->vm_file->f_mapping); } else { - i_mmap_unlock_write(vma->vm_file->f_mapping); hugetlb_vma_unlock_write(vma); } + + if (vma->vm_file) + i_mmap_unlock_write(vma->vm_file->f_mapping); } void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start, --- a/mm/memory.c~hugetlbfs-close-race-between-madv_dontneed-and-page-fault +++ a/mm/memory.c @@ -1683,7 +1683,7 @@ static void unmap_single_vma(struct mmu_ if (vma->vm_file) { zap_flags_t zap_flags = details ? details->zap_flags : 0; - __unmap_hugepage_range_final(tlb, vma, start, end, + __unmap_hugepage_range(tlb, vma, start, end, NULL, zap_flags); } } else @@ -1728,8 +1728,12 @@ void unmap_vmas(struct mmu_gather *tlb, start_addr, end_addr); mmu_notifier_invalidate_range_start(&range); do { - unmap_single_vma(tlb, vma, start_addr, end_addr, &details, + unsigned long start = start_addr; + unsigned long end = end_addr; + hugetlb_zap_begin(vma, &start, &end); + unmap_single_vma(tlb, vma, start, end, &details, mm_wr_locked); + hugetlb_zap_end(vma, &details); } while ((vma = mas_find(mas, tree_end - 1)) != NULL); mmu_notifier_invalidate_range_end(&range); } @@ -1753,9 +1757,7 @@ void zap_page_range_single(struct vm_are lru_add_drain(); mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, address, end); - if (is_vm_hugetlb_page(vma)) - adjust_range_if_pmd_sharing_possible(vma, &range.start, - &range.end); + hugetlb_zap_begin(vma, &range.start, &range.end); tlb_gather_mmu(&tlb, vma->vm_mm); update_hiwater_rss(vma->vm_mm); mmu_notifier_invalidate_range_start(&range); @@ -1766,6 +1768,7 @@ void zap_page_range_single(struct vm_are unmap_single_vma(&tlb, vma, address, end, details, false); mmu_notifier_invalidate_range_end(&range); tlb_finish_mmu(&tlb); + hugetlb_zap_end(vma, details); } /** _ Patches currently in -mm which might be from riel(a)surriel.com are hugetlbfs-clear-resv_map-pointer-if-mmap-fails.patch hugetlbfs-extend-hugetlb_vma_lock-to-private-vmas.patch hugetlbfs-close-race-between-madv_dontneed-and-page-fault.patch

1 year, 3 months

1
0
0 0

+ hugetlbfs-clear-resv_map-pointer-if-mmap-fails.patch added to mm-hotfixes-unstable branch

by Andrew Morton

The patch titled Subject: hugetlbfs: clear resv_map pointer if mmap fails has been added to the -mm mm-hotfixes-unstable branch. Its filename is hugetlbfs-clear-resv_map-pointer-if-mmap-fails.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: Rik van Riel <riel(a)surriel.com> Subject: hugetlbfs: clear resv_map pointer if mmap fails Date: Thu, 5 Oct 2023 23:59:06 -0400 Patch series "hugetlbfs: close race between MADV_DONTNEED and page fault", v7. Malloc libraries, like jemalloc and tcalloc, take decisions on when to call madvise independently from the code in the main application. This sometimes results in the application page faulting on an address, right after the malloc library has shot down the backing memory with MADV_DONTNEED. Usually this is harmless, because we always have some 4kB pages sitting around to satisfy a page fault. However, with hugetlbfs systems often allocate only the exact number of huge pages that the application wants. Due to TLB batching, hugetlbfs MADV_DONTNEED will free pages outside of any lock taken on the page fault path, which can open up the following race condition: CPU 1 CPU 2 MADV_DONTNEED unmap page shoot down TLB entry page fault fail to allocate a huge page killed with SIGBUS free page Fix that race by extending the hugetlb_vma_lock locking scheme to also cover private hugetlb mappings (with resv_map), and pulling the locking from __unmap_hugepage_final_range into helper functions called from zap_page_range_single. This ensures page faults stay locked out of the MADV_DONTNEED VMA until the huge pages have actually been freed. This patch (of 3): Hugetlbfs leaves a dangling pointer in the VMA if mmap fails. This has not been a problem so far, but other code in this patch series tries to follow that pointer. Link: https://lkml.kernel.org/r/20231006040020.3677377-1-riel@surriel.com Link: https://lkml.kernel.org/r/20231006040020.3677377-2-riel@surriel.com Fixes: 04ada095dcfc ("hugetlb: don't delete vma_lock in hugetlb MADV_DONTNEED processing") Signed-off-by: Mike Kravetz <mike.kravetz(a)oracle.com> Signed-off-by: Rik van Riel <riel(a)surriel.com> Cc: Matthew Wilcox (Oracle) <willy(a)infradead.org> Cc: Muchun Song <muchun.song(a)linux.dev> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/hugetlb.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/mm/hugetlb.c~hugetlbfs-clear-resv_map-pointer-if-mmap-fails +++ a/mm/hugetlb.c @@ -1138,8 +1138,7 @@ static void set_vma_resv_map(struct vm_a VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma); VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma); - set_vma_private_data(vma, (get_vma_private_data(vma) & - HPAGE_RESV_MASK) | (unsigned long)map); + set_vma_private_data(vma, (unsigned long)map); } static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags) @@ -6811,8 +6810,10 @@ out_err: */ if (chg >= 0 && add < 0) region_abort(resv_map, from, to, regions_needed); - if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) + if (vma && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { kref_put(&resv_map->refs, resv_map_release); + set_vma_resv_map(vma, NULL); + } return false; } _ Patches currently in -mm which might be from riel(a)surriel.com are hugetlbfs-clear-resv_map-pointer-if-mmap-fails.patch hugetlbfs-extend-hugetlb_vma_lock-to-private-vmas.patch hugetlbfs-close-race-between-madv_dontneed-and-page-fault.patch

1 year, 3 months

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror October 2023