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2026-07-14hfsplus: validate thread record before delete key rebuildKyle Zeng
hfsplus_delete_cat() is called with str == NULL when the last open reference to an unlinked HFS+ hardlink backing inode is closed. In that case, the function finds the catalog thread by CNID and rebuilds the catalog key from thread.nodeName. That reconstruction path reads thread.nodeName.length directly from the catalog B-tree into fd.search_key and then copies length * 2 bytes into fd.search_key->cat.name.unicode. It does not first check that the found record is a thread record or that its size matches the thread name. A corrupted image can therefore provide an oversized thread name length and make hfs_bnode_read() write past the catalog search-key allocation. Read the CNID record through hfsplus_brec_read_cat(), which bounds the record read to sizeof(hfsplus_cat_entry) and verifies that a thread record's size exactly matches nodeName.length. Together, these checks ensure an accepted thread name fits HFSPLUS_MAX_STRLEN. Reject non-thread records before building the delete key from the validated thread name. Share the thread-record-type helper between hfsplus_find_cat() and hfsplus_delete_cat(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Assisted-by: Codex:gpt-5.6 Signed-off-by: Kyle Zeng <kylebot@openai.com> Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com> Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com> Link: https://lore.kernel.org/r/20260709010203.49664-1-kylebot@openai.com Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
2026-07-14hfs: validate catalog CNIDs before instantiating inodesDavid Maximiliano Hermitte
hfs_cat_find_brec() first resolves a catalog thread record by CNID and then looks up the corresponding catalog record by parent/name. On a corrupted filesystem image, the second lookup may find a record whose CNID does not match the CNID that was requested. Validate the record found by the second lookup before returning it. Read the already-found record with hfs_bnode_read(), require the exact fixed size for file and directory records, reject other record types, and verify that the stored CNID matches the requested CNID. Also validate reserved CNIDs in hfs_read_inode() before populating the inode, propagate hfs_read_inode() failures from the resource-fork lookup path, and reject bad resource-fork and root inodes. Keep hfs_write_inode() unchanged, so corrupted catalog records are rejected before reaching its existing reserved-CNID BUG() path. Reported-by: syzbot+97e301b4b82ae803d21b@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=97e301b4b82ae803d21b Cc: George Anthony Vernon <contact@gvernon.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: David Maximiliano Hermitte <davemadmaxxx@gmail.com> Reviewed-by: Viacheslav Dubeyko <slava@dubeyko.com> Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com> Link: https://lore.kernel.org/r/20260708215636.73815-1-davemadmaxxx@gmail.com Signed-off-by: Viacheslav Dubeyko <slava@dubeyko.com>
2026-07-14fs/ntfs3: fix slab-out-of-bounds write in ni_create_attr_list()HE WEI(ギカク)
ni_create_attr_list() allocates a fixed buffer of al_aligned(record_size) (== record_size) bytes and then walks every attribute of the primary MFT record, writing one ATTR_LIST_ENTRY per attribute and advancing the cursor by le_size(name_len), with no check against the end of the buffer; the total size is only computed after the loop. A minimum-size resident attribute occupies SIZEOF_RESIDENT (0x18 = 24) bytes on disk, but an unnamed attribute expands to le_size(0) (0x20 = 32) bytes in the list. Because the number of attributes in a record is not bounded (mi_enum_attr() accepts arbitrarily many equal-type, nameless minimum-size attributes), a crafted record packed with such attributes produces a list larger than record_size and overflows the heap buffer. This is reachable from a crafted, loop-mounted NTFS image: opening the file and adding an attribute (e.g. via setxattr) drives ntfs_set_ea() -> ni_insert_resident() -> ni_insert_attr() -> ni_ins_attr_ext() -> ni_create_attr_list(). BUG: KASAN: slab-out-of-bounds in ni_create_attr_list+0xc48/0x1058 Write of size 4 at addr ffff000008984c00 by task setfattr/345 ni_create_attr_list+0xc48/0x1058 ni_ins_attr_ext+0x510/0x7c0 ni_insert_attr+0x3f8/0x70c ni_insert_resident+0xc8/0x3b0 ntfs_set_ea+0x66c/0xd28 ntfs_setxattr+0x4d8/0x5b0 __arm64_sys_setxattr+0xa4/0x124 Allocated by task 345: ni_create_attr_list+0x188/0x1058 The buggy address belongs to the cache kmalloc-1k of size 1024 (the write lands at object+1024). Size the buffer from the actual attributes instead of assuming a single record_size is always enough. Fixes: 4342306f0f0d ("fs/ntfs3: Add file operations and implementation") Reported-by: HE WEI(ギカク) <skyexpoc@gmail.com> Signed-off-by: HE WEI(ギカク) <skyexpoc@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-07-14fs/ntfs3: cosmetic fixes and improvementsKonstantin Komarov
Get rid of unnecessary duplications, improve readability, clang-format the code. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-07-14fs/ntfs3: widen inode/record number storage to u64Konstantin Komarov
NTFS inode and MFT record numbers are inherently 64-bit values, but several places stored them in 'unsigned long' (or CLST, a u32). On 32-bit architectures 'unsigned long' is only 32 bits wide, so the upper bits of a record reference are truncated. Store these values in u64 and update the associated format specifiers (%lx -> %llx) accordingly. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-07-14Merge tag 'for-7.2-rc3-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - fix root structure leak after relocation error - fix optimization when checksums are read from commit root, fall back to checksum root during relocation - in tree-checker, validate length of inode reference in items - validate properties before setting them - validate free space cache entries on load - transaction abort fixes - fix printing of internal trees as signed numbers - add error messages after critical lzo compression errors * tag 'for-7.2-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: print-tree: print header owner as signed btrfs: decentralize transaction aborts in create_reloc_root() btrfs: tree-checker: validate INODE_REF's namelen btrfs: lzo: add error message for invalid headers btrfs: fallback to transaction csum tree on a commit root csum miss btrfs: fix root leak if its reloc root is unexpected in merge_reloc_roots() btrfs: reject free space cache with more entries than pages btrfs: fix transaction abort logic in btrfs_fileattr_set() btrfs: validate properties before setting them
2026-07-14xfs: don't zap bmbt forks if they are MAXLEVELS tallDarrick J. Wong
LOLLM noticed a discrepancy between the bmbt level checks in the libxfs bmbt code vs. the inode repair code. We do actually allow a bmbt root that proclaims to have a height of XFS_BM_MAXLEVELS. Cc: stable@vger.kernel.org # v6.8 Fixes: e744cef2060559 ("xfs: zap broken inode forks") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: clamp timestamp nanoseconds correctlyDarrick J. Wong
LOLLM noticed an off-by-one error in the nsec clamping; fix that so that we never have tv_nsec == 1e9. Cc: stable@vger.kernel.org # v6.8 Fixes: 2d295fe65776d1 ("xfs: repair inode records") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: fully check the parent handle when it points to the rootdirDarrick J. Wong
LOLLM noticed that the directory tree path checking declares the path to be ok if the inumber in the parent pointer reaches the root directory. Unfortunately, it neglects to check that the generation is correct. Fix that by moving the generation check up. Cc: stable@vger.kernel.org # v6.10 Fixes: 928b721a11789a ("xfs: teach online scrub to find directory tree structure problems") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: handle non-inode owners for rtrmap record checkingDarrick J. Wong
LOLLM noticed that two helper functions in the rtrmapbt scrub code don't actually handle non-inode owners correctly -- CoW staging extents and rgsuperblock extents are not shareable, but they are mergeable. Fix these two helpers. Cc: stable@vger.kernel.org # v6.14 Fixes: 2d9a3e98053e8c ("xfs: allow overlapping rtrmapbt records for shared data extents") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: fix off-by-one error when calling xchk_xref_has_rt_ownerDarrick J. Wong
LOLLM noticed an off-by-one error when computing the length of the rtrmap to cross-check. Cc: stable@vger.kernel.org # v6.14 Fixes: 037a44d8277adf ("xfs: cross-reference the realtime rmapbt") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: set xfarray killable sort correctlyDarrick J. Wong
LOLLM noticed that we *disable* interruptible sorts when the KILLABLE flag is set. This is backwards. Fix the incorrect logic, and rename the variable to make the connection more obvious. Cc: stable@vger.kernel.org # v6.10 Fixes: 271557de7cbfde ("xfs: reduce the rate of cond_resched calls inside scrub") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: grab rtrmap btree when checking rgsuperDarrick J. Wong
LOLLM noticed that we aren't grabbing the rtrmap btree when we check the realtime group superblock. As a result, none of the cross-referencing checks have ever run. Fix this. Cc: stable@vger.kernel.org # v6.14 Fixes: 428e4884656db9 ("xfs: allow queued realtime intents to drain before scrubbing") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: write the rg superblock when fixing itDarrick J. Wong
The rtgroup superblock fixer should write the rtgroup superblock. LOLLM noticed this, oops. :/ Cc: stable@vger.kernel.org # v6.13 Fixes: 1433f8f9cead37 ("xfs: repair realtime group superblock") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: use the rt version of the cow staging checkerDarrick J. Wong
LOLLM also noticed that xchk_rtrmapbt_xref ought to be using the rtdev version of the "is this a cow extent?" helper function, not the datadev one. Cc: stable@vger.kernel.org # v6.14 Fixes: 91683bb3f264c0 ("xfs: cross-reference checks with the rt refcount btree") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: use rtrefcount btree cursor in xchk_xref_is_rt_cow_stagingDarrick J. Wong
LOLLM points out that we pass the wrong btree cursor here. We want the rtrefcount btree cursor, not the non-rt one. This is fairly benign since it only affects tracing data. Cc: stable@vger.kernel.org # v6.14 Fixes: 91683bb3f264c0 ("xfs: cross-reference checks with the rt refcount btree") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: don't wrap around quota ids in dqiterateDarrick J. Wong
LOLLM noticed that q_id is an unsigned 32-bit variable. If it happens to be set to XFS_DQ_ID_MAX due to a filesystem that actually has a dquot for ID_MAX, then this addition will truncate to zero and the iteration starts over. Fix this by casting to u64. Cc: stable@vger.kernel.org # v6.8 Fixes: 21d7500929c8a0 ("xfs: improve dquot iteration for scrub") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: move cow_replace_mapping to xfs_bmap_util.cDarrick J. Wong
Move the actual details of (partially) replacing a COW fork mapping to xfs_bmap_util.c so that all the code doing hairy operations on subsets of bmbt_irecs are kept together. Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: make cow repair somewhat flaky when debugging knob enabledDarrick J. Wong
Introduce a new behavior for the cow fork repair code: if the debugging knob is enabled, we'll pick a random subrange of each cow fork mapping to mark as bad. This will exercise the xrep_cow_replace_mapping more thoroughly. Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: don't replace the wrong part of the cow forkDarrick J. Wong
LOLLM points out that xfs_iext_lookup_extent can return a @got where got->br_startoff < startoff. In this case, xrep_cow_replace_range replaces the entire mapping instead of just the part that had been marked bad in the bitmap, but advances the bitmap cursor in xrep_cow_replace by the amount replaced. As a result, we fail to replace the end of the bad range, and replace part of the good range. Fix this by rewriting the replace method to handle replacing the middle of a cow fork mapping. This we do by returning both the current mapping as @got, and the subset of the mapping that we want to replace as @rep, using @rep to store the results of the new allocation, and comparing @rep to @got to figure out the exact transformations needed. Cc: stable@vger.kernel.org # v6.8 Fixes: dbbdbd0086320a ("xfs: repair problems in CoW forks") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14xfs: resample the data fork mapping after cycling ILOCKDarrick J. Wong
xfs_reflink_fill_{cow_hole,delalloc} are both presented with an inode, a data fork mapping, and a cow fork mapping. Unfortunately, these two helpers cycle the ILOCK to grab a transaction, which means that the mappings are stale as soon as we reacquire the ILOCK. Currently we refresh the cow fork mapping by re-calling xfs_find_trim_cow_extent, but we don't refresh the data fork mapping beforehand, which means that the xfs_bmap_trim_cow in that function queries the refcount btree about the wrong physical blocks and returns an inaccurate value in *shared. If *shared is now false, the directio write proceeds with a stale data fork mapping. Fix this by querying the data fork mapping if the sequence counter changes across the ILOCK cycle. Cc: hch@lst.de Cc: stable@vger.kernel.org # v4.11 Fixes: 3c68d44a2b49a0 ("xfs: allocate direct I/O COW blocks in iomap_begin") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-14btrfs: fix GET_SUBVOL_INFO after compat refactorDaan De Meyer
btrfs_search_slot() returns a positive value when the search key does not exactly match an item. This is expected here, since offset 0 is used to find the first ROOT_BACKREF for the subvolume and the actual key has the parent root ID as its offset. Before the compat ioctl refactoring, the native handler still copied the filled structure to userspace when the search returned 1. After the lookup was moved to a shared helper, both native and compat callers treat the positive return value as a failure and skip copy_to_user(), leaving BTRFS_IOC_GET_SUBVOL_INFO unusable for non-top-level subvolumes. Reset ret after successfully validating and reading the ROOT_BACKREF so the helper reports success and both callers copy the result to userspace. Fixes: 538e5bdbc899 ("btrfs: add 32-bit compat ioctl for BTRFS_IOC_GET_SUBVOL_INFO") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Daan De Meyer <daan@amutable.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: free mapping node on duplicate reloc root insertGuanghui Yang
__add_reloc_root() allocates a mapping_node before inserting it into rc->reloc_root_tree. If rb_simple_insert() finds an existing entry, it returns the existing rb_node and leaves the newly allocated node unlinked. The error path then returns -EEXIST without freeing the new node. Since the node was never inserted into reloc_root_tree, the later cleanup in put_reloc_control() cannot find it either. Free the newly allocated node before returning -EEXIST. The callers currently assert that -EEXIST should not happen, so this is a defensive cleanup for an unexpected duplicate insert path. If the path is ever reached, the local allocation should still be released. Fixes: 57a304cfd43b ("btrfs: do not panic in __add_reloc_root") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Guanghui Yang <3497809730@qq.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: fix a regression where PAGECACHE_TAG_DIRTY is never clearedQu Wenruo
[BUG] The following script (already submitted as generic/798) will report incorrect dirty page numbers, with 64K page size systems and 4K fs block size: # mkfs.btrfs -s 4k -f $dev # mount $dev $mnt # xfs_io -f -c "pwrite 0 64K" -c fsync -c "cachestat 0 64K" $mnt/foobar Cached: 1, Dirty: 1, Writeback: 0, Evicted: 0, Recently Evicted: 0 Note that the dirtied page number is still 1. [CAUSE] The cachestat() goes through the XArray of the page cache, but instead of checking each folio's flag, it uses the PAGECACHE_TAG_DIRTY tag to report dirty pages. Since commit 095be159f3eb ("btrfs: unify folio dirty flag clearing"), btrfs replaced a folio_clear_dirty_for_io() call inside extent_write_cache_pages() with folio_test_dirty(). This will cause the following call sequence for the folio at file offset 0: extent_write_cache_pages() |- folio_test_dirty() | The folio is still dirty, continue to writeback. | |- extent_writepage() |- extent_writepage_io() |- submit_one_sector() for range [0, 4K) | |- btrfs_folio_clear_dirty() | |- btrfs_folio_set_writeback() | |- folio_start_writeback() | It's the first writeback block, we set the writeback | flag for the folio. | But the folio is still dirty, PAGECACHE_TAG_DIRTY is | kept | |- submit_one_sector() for range [4K, 8K) | |- btrfs_folio_clear_dirty() | |- btrfs_folio_set_writeback() | The folio already has writeback flag, no need to call | folio_start_writeback() | | ... |- submit_one_sector() for range [60K, 64K) |- btrfs_folio_clear_dirty() |- btrfs_folio_set_writeback() The folio already has writeback flag, no need to call folio_start_writeback() So the PAGECACHE_TAG_DIRTY is never cleared. Meanwhile for the old code, before that commit, the sequence looks like: extent_write_cache_pages() |- folio_clear_dirty_for_io() | The folio is still dirty, so continue to writeback. | But the folio dirty flag is cleared now. | |- extent_writepage() |- extent_writepage_io() |- submit_one_sector() for range [0, 4K) | |- btrfs_folio_clear_dirty() | |- btrfs_folio_set_writeback() | |- folio_start_writeback() | |- xas_clear(PAGECACHE_TAG) | | It's the first writeback block, we set the writeback | flag for the folio. | And the folio is not dirty, PAGECACHE_TAG_DIRTY is | cleared | |- submit_one_sector() for range [4K, 8K) | |- btrfs_folio_clear_dirty() | |- btrfs_folio_set_writeback() | The folio already has writeback flag, no need to call | folio_start_writeback() | | ... |- submit_one_sector() for range [60K, 64K) |- btrfs_folio_clear_dirty() |- btrfs_folio_set_writeback() The folio already has writeback flag, no need to call folio_start_writeback() Unlike the new code, old code will clear PAGECACHE_TAG_DIRTY for the first writeback block. There is a deeper problem, dirty and writeback folio flags are updated at very different timing. The dirty flag is only cleared when the last sub-folio block has dirty flag cleared. But the writeback flag is set when the first block starts writeback, and later blocks that go through writeback will not call folio_start_writeback() again. If we rely on folio_start_writeback() to update the PAGECACHE_TAG_DIRTY and PAGECACHE_TAG_TOWRITE, it will always be incorrect in one way or another. [FIX] Do not let folio_start_writeback() do any PAGECACHE_TAG_TOWRITE handling. Instead, manually clear both PAGECACHE_TAG_TOWRITE and PAGECACHE_TAG_DIRTY flags when the folio is no longer dirty during btrfs_subpage_set_writeback(). However this is only a hot-fix, for the long term solution we will follow iomap, by calling folio_start_writeback() immediately for the whole folio, and folio_end_writeback() after all writeback finished for the folio. Fixes: 095be159f3eb ("btrfs: unify folio dirty flag clearing") Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: don't propagate EXTENT_FLAG_LOGGING to split extent mapsLeo Martins
When btrfs_drop_extent_map_range() splits an extent map, the new split maps inherit the original map's flags through a local 'flags' variable. Commit f86f7a75e2fb ("btrfs: use the flags of an extent map to identify the compression type") changed the EXTENT_FLAG_LOGGING clearing to operate on em->flags instead of that local 'flags' copy, so a split of an extent map that is currently being logged wrongly inherits EXTENT_FLAG_LOGGING. The flag is then never cleared on the split, and when it is freed while still on the inode's modified_extents list (for example by the extent map shrinker) it trips the WARN_ON(!list_empty(&em->list)) in btrfs_free_extent_map() and leads to a use-after-free. Clear EXTENT_FLAG_LOGGING from the local 'flags' copy used for the splits and only clear EXTENT_FLAG_PINNED from em->flags, restoring the behaviour prior to f86f7a75e2fb. CC: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/all/20260629-btrfs-skip-logging-v1-1-4e3a28c1acaf@kernel.org/ Fixes: f86f7a75e2fb ("btrfs: use the flags of an extent map to identify the compression type") Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Leo Martins <loemra.dev@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: fix u32 to s64 type conversion in dirty_metadata_bytes accountingDave Chen
The percpu_counter dirty_metadata_bytes is updated by negating eb->len and passing it to percpu_counter_add_batch(), whose amount parameter is s64. Since commit 84cda1a6087d ("btrfs: cache folio size and shift in extent_buffer"), eb->len is u32. The u32 result of -eb->len, when widened to the s64 parameter, becomes a large positive value instead of the intended negative value. For eb->len == 16384 the counter adds +4294950912 instead of subtracting 16384. The counter therefore grows on every metadata writeback instead of shrinking by the extent buffer size, permanently exceeding BTRFS_DIRTY_METADATA_THRESH and causing __btrfs_btree_balance_dirty() to trigger balance_dirty_pages_ratelimited() unconditionally, adding unnecessary writeback pressure. Cast eb->len to s64 before negation at both call sites so the subtraction is performed in signed 64-bit arithmetic. Reviewed-by: Filipe Manana <fdmanana@suse.com> Fixes: 84cda1a6087d ("btrfs: cache folio size and shift in extent_buffer") Signed-off-by: Dave Chen <davechen@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: fix NULL pointer deref during assertion in btrfs_backref_free_node()Filipe Manana
In btrfs_backref_free_node() we have the following assertion: ASSERT(node->eb == NULL, "node->eb->start=%llu", node->eb->start); and a user reported the following crash: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 UID: 0 PID: 10422 Comm: syz.0.17 Not tainted 7.1.0-02765-g6b5a2b7d9bc1-dirty #44 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:btrfs_backref_free_node fs/btrfs/backref.c:3057 [inline] RIP: 0010:btrfs_backref_free_node+0xb9/0x200 fs/btrfs/backref.c:3051 Code: 00 fc ff (...) RSP: 0018:ffa0000006b0f3c0 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff840eb78b RDX: 0000000000000000 RSI: ffffffff840eafa5 RDI: ff110000742ab768 RBP: ff110000742ab700 R08: 0000000000000000 R09: 0000000000000000 R10: ff110000742ab700 R11: 00000000000a81f9 R12: ff11000107a92020 R13: ff1100005c182ea8 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000555575536500(0000) GS:ff11000183985000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa3d0e9d580 CR3: 000000002232a000 CR4: 0000000000753ef0 PKRU: 00000000 Call Trace: <TASK> btrfs_backref_cleanup_node+0x27/0x30 fs/btrfs/backref.c:3133 relocate_tree_block fs/btrfs/relocation.c:2604 [inline] relocate_tree_blocks+0x11b0/0x1a20 fs/btrfs/relocation.c:2707 relocate_block_group+0x499/0xf30 fs/btrfs/relocation.c:3635 do_nonremap_reloc fs/btrfs/relocation.c:5323 [inline] btrfs_relocate_block_group+0x1749/0x5fb0 fs/btrfs/relocation.c:5490 btrfs_relocate_chunk+0x12b/0x950 fs/btrfs/volumes.c:3647 __btrfs_balance fs/btrfs/volumes.c:4586 [inline] btrfs_balance+0x1c7f/0x55c0 fs/btrfs/volumes.c:4973 btrfs_ioctl_balance fs/btrfs/ioctl.c:3474 [inline] btrfs_ioctl+0x38a4/0x5d20 fs/btrfs/ioctl.c:5570 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18f/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x11f/0x860 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb38e3b56dd Code: 02 b8 ff (...) RSP: 002b:00007fff04115788 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fb38f6b0020 RCX: 00007fb38e3b56dd RDX: 00002000000003c0 RSI: 00000000c4009420 RDI: 0000000000000004 RBP: 00007fb38e451b48 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb38f6b0020 R15: 00007fb38f6b002c </TASK> It seems that this happens on some systems for some reason, when the ASSERT() macro calls the inline function verify_assert_printk_format() to evaluate the format string and arguments, causing the NULL pointer dereference on node->eb. So change the assertion to check for a NULL node->eb before dereferencing it. Also, while at it, make the assertion more useful by printing the owner of the extent buffer as well as its level. Reported-by: Yue Sun <samsun1006219@gmail.com> Link: https://lore.kernel.org/linux-btrfs/20260626065542.38413-1-samsun1006219@gmail.com/ Fixes: c4e7778580d6 ("btrfs: use verbose assertions in backref.c") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: only account delalloc bytes for regular file inodes in btrfs_getattr()Dave Chen
btrfs_getattr() unconditionally reads BTRFS_I(inode)->new_delalloc_bytes and adds it (sector-aligned) to stat->blocks for every inode type. However, new_delalloc_bytes lives in a union with last_dir_index_offset: union { u64 new_delalloc_bytes; /* files only */ u64 last_dir_index_offset; /* directories only */ }; For a directory inode this memory holds last_dir_index_offset, which is set during directory logging (e.g. flush_dir_items_batch()) to the offset of the last logged BTRFS_DIR_INDEX_KEY. That offset grows with the number of entries ever created in the directory (dir indexes are monotonic and never reused), so it can be arbitrarily large. As a result, after a directory has been logged (e.g. via an fsync that triggers directory logging), btrfs_getattr() reports inflated st_blocks for that directory. The inflation is purely in-core and disappears after the inode is evicted and reloaded (btrfs_alloc_inode() zeroes the union), e.g. after a remount. Reproducer (on a btrfs filesystem): D=/mnt/btrfs/d mkdir -p $D for i in $(seq 1 20000); do touch $D/f$i; done sync # commit, push dir index high touch $D/trigger # dirty the dir in a new transaction xfs_io -c fsync $D # log the directory -> sets last_dir_index_offset stat -c '%b' $D # st_blocks is now inflated (e.g. 40) # umount + mount -> st_blocks drops back to the correct value The evict path already knows this union is type-dependent and guards the corresponding WARN_ON with !S_ISDIR() in btrfs_destroy_inode(); only btrfs_getattr() was missing the equivalent check. Only read new_delalloc_bytes for regular files, which are the only inodes that ever set it. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Dave Chen <davechen@synology.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: reject inline file extents item in get_new_location()Qu Wenruo
Commit a6908f88c9da ("btrfs: validate data reloc tree file extent item members") introduced extra checks on file extent items for data reloc inodes, but it checked the file extent offset without checking if the file extent is inlined. This can lead to either false alerts (as the offset member is inside the inlined data) or even reading beyond the item range. This has already triggered a warning in a syzbot report. Although the root fix is to avoid compression for data reloc inodes, for the sake of consistency, reject inlined file extents first. Fixes: a6908f88c9da ("btrfs: validate data reloc tree file extent item members") CC: stable@vger.kernel.org Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: do not try compression for data reloc inodesQu Wenruo
[BUG] There is a syzbot report that the check inside get_new_location() triggered: BTRFS info (device loop0): found 31 extents, stage: move data extents BTRFS info (device loop0): leaf 8908800 gen 16 total ptrs 28 free space 1676 owner 18446744073709551607 item 0 key (256 INODE_ITEM 0) itemoff 3835 itemsize 160 inode generation 5 transid 0 size 0 nbytes 0 block group 0 mode 40755 links 1 uid 0 gid 0 rdev 0 sequence 0 flags 0x0 atime 1669132761.0 ctime 1669132761.0 mtime 1669132761.0 otime 0.0 item 1 key (256 INODE_REF 256) itemoff 3823 itemsize 12 index 0 name_len 2 item 2 key (258 INODE_ITEM 0) itemoff 3663 itemsize 160 inode generation 1 transid 16 size 733184 nbytes 106496 block group 0 mode 100600 links 0 uid 0 gid 0 rdev 0 sequence 24 flags 0x18 item 3 key (258 EXTENT_DATA 0) itemoff 3595 itemsize 68 generation 16 type 0 inline extent data size 47 ram_bytes 4096 compression 1 [...] item 27 key (18446744073709551611 ORPHAN_ITEM 258) itemoff 2376 itemsize 0 BTRFS error (device loop0): unexpected non-zero offset in file extent item for data reloc inode 258 key offset 0 offset 9277520992061368337 ------------[ cut here ]------------ btrfs_abort_should_print_stack(__error) [CAUSE] The above dump tree shows the first file extent item is inlined, which should make no sense for data reloc inodes, as such inodes just represent where the data extents are in the relocation destination chunk. However the relocation path preallocates space for each block, then dirties them, cluster by cluster. It's possible to have a single block at the beginning of the block group, and no other block in the same cluster. So relocation will preallocate a file extent for that block and dirty the first block. Then memory pressure forces the data reloc inode to be written back, before any other blocks are dirtied/allocated. Finally commit 3eaf5f082c4c ("btrfs: extract inlined creation into a dedicated delalloc helper") changed the sequence of delalloc. Before that commit we always tried NOCOW first, so that dirtied block would be written back into the preallocated space, and appear as a regular extent. But with that commit, we always try inline first, and since compression is forced, we try compressing the first block, and then inline the compressed data, resulting in the above inlined file extent in the data reloc tree. Then the check in get_new_location() will check the file offset, without checking if the file extent is inlined or not, resulting in the above failure. [FIX] Do not allow compression for data reloc inodes. Since data reloc inode sizes are always block aligned, as long as we do not compress, @data_len will always be at least one block, and that will cause can_cow_file_range_inline() to return false, thus no inlined extent will be created. Reported-by: syzbot+d950c6ba09b79f6e1864@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/6a373dc5.764cf64f.168fbe.0001.GAE@google.com/ Fixes: 3eaf5f082c4c ("btrfs: extract inlined creation into a dedicated delalloc helper") CC: stable@vger.kernel.org Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: fix reloc root cleanup in merge_reloc_roots()Filipe Manana
If the root we got has zero root refs in its root item, we are resetting the root's ->reloc_root without using barriers like we do everywhere else. Sashiko complained about this while reviewing another patch, and it's correct (see the Link tag below). Also, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless the root points to the reloc root we have. Fix this by using clear_reloc_root(), which issues the memory barrier after setting the root's ->reloc_root to NULL and before clearing the bit BTRFS_ROOT_DEAD_RELOC_TREE from the root. Link: https://sashiko.dev/#/patchset/cf84f1a217c719e25b6b69e4298dd7afd36c9427.1781194426.git.fdmanana%40suse.com Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-14btrfs: fix use-after-free on reloc root after error in insert_dirty_subvol()Filipe Manana
If during relocation we fail in insert_dirty_subvol() because btrfs_update_reloc_root() returned an error, we will leave a root's reloc_root field pointing to a reloc root that was freed instead of NULL, resulting later in a use-after-free, or double free attempt during unmount. The sequence of steps is this: 1) During relocation the call to btrfs_update_reloc_root() in insert_dirty_subvol() fails, so insert_dirty_subvol() returns the error to merge_reloc_root() without adding the root to the list rc->dirty_subvol_roots; 2) Then merge_reloc_root() aborts the current transaction because insert_dirty_subvol() returned an error; 3) Up the call chain, merge_reloc_roots() gets the error, adds the reloc root for root X to the local reloc_roots list and jumps to the 'out' label, where it calls free_reloc_roots() to free all the reloc roots in the local reloc_roots list. This frees the reloc root for root X; 4) We go up the call chain to relocate_block_group() which calls clean_dirty_subvols() to go over dirty roots and set their ->reloc_root field to NULL, but root X is not in the dirty_subvol_roots list, so its ->reloc_root still points to a reloc root; 5) Relocation finishes, with an error and a transaction abort, but the ->reloc_root field for root X still points to the reloc root that was freed in step 3; 6) When unmounting the fs we end up calling: btrfs_free_fs_roots() btrfs_drop_and_free_fs_root() --> calls btrfs_put_root() against root X's ->reloc_root which is not NULL and points to the already freed reloc root in step 4 above Resulting in a use-after-free to a double free attempt. Syzbot reported this with the following dmesg/syslog: [ 106.004389][ T5339] BTRFS error (device loop0 state A): Transaction aborted (error -5) [ 106.014266][ T5339] BTRFS: error (device loop0 state A) in merge_reloc_root:1655: errno=-5 IO failure [ 106.021891][ T1061] BTRFS error (device loop0 state A): error while writing out transaction: -5 [ 106.026964][ T1061] BTRFS warning (device loop0 state A): Skipping commit of aborted transaction. [ 106.033807][ T5340] BTRFS error (device loop0 state A): bdev /dev/loop0 errs: wr 3, rd 0, flush 0, corrupt 0, gen 0 [ 106.039265][ T1061] BTRFS: error (device loop0 state A) in cleanup_transaction:2067: errno=-5 IO failure [ 106.044382][ T5339] BTRFS info (device loop0 state EA): forced readonly [ 106.074329][ T5339] BTRFS: error (device loop0 state EA) in merge_reloc_roots:1887: errno=-5 IO failure [ 106.081004][ T5356] BTRFS info (device loop0 state EA): scrub: started on devid 1 [ 106.085611][ T5339] BTRFS info (device loop0 state EA): balance: ended with status: -30 [ 106.089517][ T5356] BTRFS info (device loop0 state EA): scrub: not finished on devid 1 with status: -30 [ 106.662365][ T5338] BTRFS info (device loop0 state EA): last unmount of filesystem 3a375e4e-b156-4d76-a2ad-16e198ce1409 [ 106.682946][ T5338] ================================================================== [ 106.686574][ T5338] BUG: KASAN: slab-use-after-free in btrfs_put_root+0x2f/0x250 [ 106.690090][ T5338] Write of size 4 at addr ffff88803f978630 by task syz.0.0/5338 [ 106.693173][ T5338] [ 106.694279][ T5338] CPU: 0 UID: 0 PID: 5338 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) [ 106.694293][ T5338] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 106.694300][ T5338] Call Trace: [ 106.694308][ T5338] <TASK> [ 106.694314][ T5338] dump_stack_lvl+0xe8/0x150 [ 106.694331][ T5338] print_address_description+0x55/0x1e0 [ 106.694343][ T5338] ? btrfs_put_root+0x2f/0x250 [ 106.694358][ T5338] print_report+0x58/0x70 [ 106.694368][ T5338] kasan_report+0x117/0x150 [ 106.694384][ T5338] ? btrfs_put_root+0x2f/0x250 [ 106.694399][ T5338] kasan_check_range+0x264/0x2c0 [ 106.694416][ T5338] btrfs_put_root+0x2f/0x250 [ 106.694430][ T5338] btrfs_drop_and_free_fs_root+0x160/0x210 [ 106.694447][ T5338] btrfs_free_fs_roots+0x2f9/0x3c0 [ 106.694464][ T5338] ? __pfx_btrfs_free_fs_roots+0x10/0x10 [ 106.694479][ T5338] ? free_root_pointers+0x5bf/0x5f0 [ 106.694494][ T5338] close_ctree+0x798/0x12d0 [ 106.694511][ T5338] ? __pfx_close_ctree+0x10/0x10 [ 106.694526][ T5338] ? _raw_spin_unlock_irqrestore+0x74/0x80 [ 106.694599][ T5338] ? rcu_preempt_deferred_qs_irqrestore+0x906/0xbc0 [ 106.694620][ T5338] ? __rcu_read_unlock+0x83/0xe0 [ 106.694636][ T5338] ? btrfs_put_super+0x48/0x1c0 [ 106.694652][ T5338] ? __pfx_btrfs_put_super+0x10/0x10 [ 106.694667][ T5338] generic_shutdown_super+0x13d/0x2d0 [ 106.694682][ T5338] kill_anon_super+0x3b/0x70 [ 106.694695][ T5338] btrfs_kill_super+0x41/0x50 [ 106.694710][ T5338] deactivate_locked_super+0xbc/0x130 [ 106.694722][ T5338] cleanup_mnt+0x437/0x4d0 [ 106.694736][ T5338] ? _raw_spin_unlock_irq+0x23/0x50 [ 106.694752][ T5338] task_work_run+0x1d9/0x270 [ 106.694769][ T5338] ? __pfx_task_work_run+0x10/0x10 [ 106.694784][ T5338] ? do_raw_spin_unlock+0x4d/0x210 [ 106.694802][ T5338] do_exit+0x70f/0x22c0 [ 106.694817][ T5338] ? trace_irq_disable+0x3b/0x140 [ 106.694835][ T5338] ? __pfx_do_exit+0x10/0x10 [ 106.694848][ T5338] ? preempt_schedule_thunk+0x16/0x30 [ 106.694863][ T5338] ? preempt_schedule_common+0x82/0xd0 [ 106.694878][ T5338] ? preempt_schedule_thunk+0x16/0x30 [ 106.694892][ T5338] do_group_exit+0x21b/0x2d0 [ 106.694906][ T5338] ? entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 106.694918][ T5338] __x64_sys_exit_group+0x3f/0x40 [ 106.694932][ T5338] x64_sys_call+0x221a/0x2240 [ 106.694944][ T5338] do_syscall_64+0x174/0x580 [ 106.694954][ T5338] ? clear_bhb_loop+0x40/0x90 [ 106.694967][ T5338] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 106.694978][ T5338] RIP: 0033:0x7f958ef9ce59 [ 106.694988][ T5338] Code: Unable to access opcode bytes at 0x7f958ef9ce2f. [ 106.694994][ T5338] RSP: 002b:00007fffd4058318 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 [ 106.695008][ T5338] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f958ef9ce59 [ 106.695015][ T5338] RDX: 00007f958c3f8000 RSI: 0000000000000000 RDI: 0000000000000000 [ 106.695022][ T5338] RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f958f1e73e0 [ 106.695028][ T5338] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 [ 106.695034][ T5338] R13: 00007f958f1e73e0 R14: 0000000000000003 R15: 00007fffd40583d0 [ 106.695046][ T5338] </TASK> [ 106.695050][ T5338] [ 106.821635][ T5338] Allocated by task 1061: [ 106.823446][ T5338] kasan_save_track+0x3e/0x80 [ 106.825498][ T5338] __kasan_kmalloc+0x93/0xb0 [ 106.827381][ T5338] __kmalloc_cache_noprof+0x31c/0x660 [ 106.829525][ T5338] btrfs_alloc_root+0x75/0x930 [ 106.831458][ T5338] read_tree_root_path+0x127/0xb00 [ 106.833556][ T5338] btrfs_read_tree_root+0x34/0x60 [ 106.835553][ T5338] create_reloc_root+0x6b3/0xcb0 [ 106.837556][ T5338] btrfs_init_reloc_root+0x2ec/0x4b0 [ 106.839557][ T5338] record_root_in_trans+0x2ab/0x350 [ 106.841685][ T5338] btrfs_record_root_in_trans+0x15c/0x180 [ 106.844237][ T5338] start_transaction+0x39c/0x1820 [ 106.846638][ T5338] btrfs_finish_one_ordered+0x88e/0x2680 [ 106.849436][ T5338] btrfs_work_helper+0x37b/0xc20 [ 106.851549][ T5338] process_scheduled_works+0xb5d/0x1860 [ 106.853807][ T5338] worker_thread+0xa53/0xfc0 [ 106.855773][ T5338] kthread+0x389/0x470 [ 106.857548][ T5338] ret_from_fork+0x514/0xb70 [ 106.859493][ T5338] ret_from_fork_asm+0x1a/0x30 [ 106.861504][ T5338] [ 106.862527][ T5338] Freed by task 5339: [ 106.864224][ T5338] kasan_save_track+0x3e/0x80 [ 106.866180][ T5338] kasan_save_free_info+0x46/0x50 [ 106.868371][ T5338] __kasan_slab_free+0x5c/0x80 [ 106.870462][ T5338] kfree+0x1c5/0x640 [ 106.872180][ T5338] __del_reloc_root+0x341/0x3b0 [ 106.874290][ T5338] free_reloc_roots+0x5f/0x90 [ 106.876282][ T5338] merge_reloc_roots+0x73f/0x8a0 [ 106.878489][ T5338] relocate_block_group+0xbcc/0xe70 [ 106.880742][ T5338] do_nonremap_reloc+0xa8/0x5b0 [ 106.882885][ T5338] btrfs_relocate_block_group+0x7e6/0xc40 [ 106.885336][ T5338] btrfs_relocate_chunk+0x115/0x820 [ 106.887502][ T5338] __btrfs_balance+0x1db0/0x2ae0 [ 106.889543][ T5338] btrfs_balance+0xaf3/0x11b0 [ 106.891456][ T5338] btrfs_ioctl_balance+0x3d3/0x610 [ 106.893672][ T5338] __se_sys_ioctl+0xfc/0x170 [ 106.895530][ T5338] do_syscall_64+0x174/0x580 [ 106.897518][ T5338] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 106.900101][ T5338] [ 106.901123][ T5338] The buggy address belongs to the object at ffff88803f978000 [ 106.901123][ T5338] which belongs to the cache kmalloc-4k of size 4096 [ 106.906907][ T5338] The buggy address is located 1584 bytes inside of [ 106.906907][ T5338] freed 4096-byte region [ffff88803f978000, ffff88803f979000) [ 106.912980][ T5338] [ 106.914022][ T5338] The buggy address belongs to the physical page: [ 106.916716][ T5338] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3f978 [ 106.920390][ T5338] head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 [ 106.923834][ T5338] flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) [ 106.927104][ T5338] page_type: f5(slab) [ 106.928898][ T5338] raw: 04fff00000000040 ffff88801ac42140 dead000000000122 0000000000000000 [ 106.932507][ T5338] raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 [ 106.936193][ T5338] head: 04fff00000000040 ffff88801ac42140 dead000000000122 0000000000000000 [ 106.939856][ T5338] head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 [ 106.943601][ T5338] head: 04fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff [ 106.947268][ T5338] head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 [ 106.950988][ T5338] page dumped because: kasan: bad access detected [ 106.953710][ T5338] page_owner tracks the page as allocated [ 106.956198][ T5338] page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 24, tgid 24 (kworker/u4:2), ts 105728970387, free_ts 29540875453 [ 106.964984][ T5338] post_alloc_hook+0x22d/0x280 [ 106.966956][ T5338] get_page_from_freelist+0x2593/0x2610 [ 106.969307][ T5338] __alloc_frozen_pages_noprof+0x18d/0x380 [ 106.971839][ T5338] allocate_slab+0x77/0x660 [ 106.973709][ T5338] refill_objects+0x339/0x3d0 [ 106.975696][ T5338] __pcs_replace_empty_main+0x321/0x720 [ 106.978136][ T5338] __kmalloc_node_track_caller_noprof+0x572/0x7b0 [ 106.981009][ T5338] __alloc_skb+0x2c1/0x7d0 [ 106.982983][ T5338] nsim_dev_trap_report_work+0x29a/0xb90 [ 106.985356][ T5338] process_scheduled_works+0xb5d/0x1860 [ 106.987710][ T5338] worker_thread+0xa53/0xfc0 [ 106.989847][ T5338] kthread+0x389/0x470 [ 106.991727][ T5338] ret_from_fork+0x514/0xb70 [ 106.993722][ T5338] ret_from_fork_asm+0x1a/0x30 [ 106.995900][ T5338] page last free pid 77 tgid 77 stack trace: [ 106.998479][ T5338] __free_frozen_pages+0xc1c/0xd30 [ 107.000819][ T5338] vfree+0x1d1/0x2f0 [ 107.002631][ T5338] delayed_vfree_work+0x55/0x80 [ 107.004848][ T5338] process_scheduled_works+0xb5d/0x1860 [ 107.007366][ T5338] worker_thread+0xa53/0xfc0 [ 107.009388][ T5338] kthread+0x389/0x470 [ 107.011177][ T5338] ret_from_fork+0x514/0xb70 [ 107.013313][ T5338] ret_from_fork_asm+0x1a/0x30 [ 107.015454][ T5338] [ 107.016460][ T5338] Memory state around the buggy address: [ 107.019052][ T5338] ffff88803f978500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 107.022691][ T5338] ffff88803f978580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 107.026264][ T5338] >ffff88803f978600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 107.029721][ T5338] ^ [ 107.032062][ T5338] ffff88803f978680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 107.035547][ T5338] ffff88803f978700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 107.038865][ T5338] ================================================================== Fix this by resetting a root's ->reloc_root if we get an error while trying to merge a reloc root. Reported-by: syzbot+b3d472d13f9d7bf20669@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-btrfs/6a1ebde9.c1435f33.112120.0176.GAE@google.com/ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-07-13fs/resctrl: Fix UAF from worker threads when domains are removedReinette Chatre
The mbm_handle_overflow() and cqm_handle_limbo() workers read event counters and may sleep while doing so. They are scheduled via delayed_work embedded in struct rdt_l3_mon_domain. Architecture allocates and frees these domains from CPU hotplug callbacks under cpus_write_lock(), and the workers acquire cpus_read_lock() to keep the domain alive across their access. A use-after-free can occur when a worker is blocked waiting for cpus_read_lock() while the hotplug core holds cpus_write_lock(): the architecture frees the rdt_l3_mon_domain that contains the worker's work_struct. When the worker unblocks, the container_of() it performs on the embedded work pointer dereferences freed memory. Drop cpus_read_lock() from the workers and instead drain pending and in-flight work synchronously before the architecture can free the domain. Since architecture offlines the domain under cpus_write_lock() after it has been unlinked from the RCU list and a grace period has elapsed, no new work can be scheduled. The cancel only needs to wait out existing work. Drop rdtgroup_mutex during CPU offline around cancel_delayed_work_sync() so that a worker waiting on the mutex can complete before re-pinning the work on a different CPU. When offlining a CPU the architecture may iterate over resources in any order. For example, the MBA control domain may be offlined before or after a corresponding L3 monitor domain. Ensure that resctrl fs cancels the workers no matter what order the architecture offlines the domains. Fixes: 24247aeeabe9 ("x86/intel_rdt/cqm: Improve limbo list processing") Closes: https://sashiko.dev/#/patchset/20260429184858.36423-1-tony.luck%40intel.com # [1] Reported-by: Sashiko <sashiko-bot@kernel.org> Co-developed-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/3f0e0752deb3421606dfc4600f0ab3a4ae098cd7.1783963505.git.reinette.chatre@intel.com
2026-07-13fs/resctrl: Prevent deadlock and use-after-free in info file handlersReinette Chatre
resctrl provides files under the info/ directory to expose global configuration and capabilities to userspace. These files are instantiated statically during filesystem mount and expose data associated with internal schema structures via kernfs private pointers. A potential deadlock exists between userspace readers of these info files and the unmount filesystem teardown process. Reading an info file invokes kernfs which acquires an active reference, after which the handler typically attempts to acquire the rdtgroup_mutex. Concurrently, unmounting the filesystem holds the rdtgroup_mutex and then attempts to recursively remove the info kernfs nodes involving kernfs_drain() which blocks until all active references are released. Another problem exists where info files might be accessed from an outdated mount if the filesystem is unmounted and remounted during a reader's execution, leading to a use-after-free when reading the now-deleted private schema data. Introduce info_kn_lock() and info_kn_unlock() helpers to coordinate locking across all info handlers. These helpers mirror similar logic used by resource group handlers by deliberately breaking the kernfs active protection before attempting to acquire the rdtgroup_mutex, preventing the deadlock. To guard against the vulnerability from rapid mount cycling, info_kn_lock() securely walks the parent lineage of the kernfs node under an RCU section to confirm the node belongs to the globally active root before permitting the operation to proceed. Convert all info file handlers to use this helper and only de-reference the schema after it is determined safe to do so. Make no attempt to output an error message to last_cmd_status on failure since failure implies there is no filesystem with which to display the error to user space. [ bp: Massage commit message. ] Closes: https://sashiko.dev/#/patchset/20260515193944.15114-1-tony.luck%40intel.com?part=3 Reported-by: Sashiko <sashiko-bot@kernel.org> Assisted-by: GitHub_Copilot:gemini-3.1-pro Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://patch.msgid.link/0b5238486bd058704d908d39a75aff2815bd18aa.1783963505.git.reinette.chatre@intel.com
2026-07-13fs/resctrl: Prevent use-after-free in rdtgroup_kn_put()Reinette Chatre
A struct rdtgroup is reference counted via rdtgroup::waitcount. Callers that need the structure to remain valid across a sleep (while waiting on acquiring rdtgroup_mutex) take a reference with rdtgroup_kn_get() and release it with rdtgroup_kn_put(). The release path is intended to serve as the fallback freer: if the count drops to zero and the group has already been marked RDT_DELETED, rdtgroup_kn_put() frees the structure. The bulk teardown paths free_all_child_rdtgrp() and rmdir_all_sub() resulting from a resctrl directory remove or resctrl fs unmount act as the primary freer: they hold rdtgroup_mutex and free each rdtgroup whose waitcount is zero, otherwise they set RDT_DELETED and leave the freeing to the last waiter. These two freers race. rdtgroup_kn_put() commits waitcount == 0 with atomic_dec_and_test() outside rdtgroup_mutex, then reads rdtgroup::flags. Between those two operations a concurrent caller of free_all_child_rdtgrp() or rmdir_all_sub() (which holds the mutex) can observe waitcount == 0 via atomic_read(), call rdtgroup_remove(), and kfree() the structure. The subsequent read of rdtgroup::flags in rdtgroup_kn_put() is then a use-after-free, and the structure may even be freed twice if the freed memory happens to satisfy the RDT_DELETED flag check. Replace the bare atomic_dec_and_test() with atomic_dec_and_mutex_lock() so that the decrement-to-zero takes rdtgroup_mutex before the count becomes globally visible. The inspection of rdtgroup::flags then runs under the same mutex held by the bulk freers, making the two paths mutually exclusive. The common case where the count does not reach zero remains lock-free. Defer kernfs_unbreak_active_protection() until after the mutex is dropped since kernfs active protections functionally wrap rdtgroup_mutex. Remove resource group, which in turn drops its kernfs reference, after kernfs protection is restored. [ bp: Split the commit messsages into smaller, easier-parseable paragraphs. ] Fixes: b8511ccc75c0 ("x86/resctrl: Fix use-after-free when deleting resource groups") Closes: https://sashiko.dev/#/patchset/20260515193944.15114-1-tony.luck%40intel.com?part=1 Reported-by: Sashiko <sashiko-bot@kernel.org> Assisted-by: GitHub_Copilot:gemini-3.1-pro Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Link: https://patch.msgid.link/8d028bbea582dc382a4cc166b235f75bd5901aea.1783963505.git.reinette.chatre@intel.com
2026-07-13fs/resctrl: Fix deadlock on errors during mountReinette Chatre
rdt_get_tree() acquires rdtgroup_mutex before calling kernfs_get_tree(). If superblock setup fails inside kernfs_get_tree(), the VFS calls .kill_sb() (rdt_kill_sb()) on the same thread before kernfs_get_tree() returns. rdt_kill_sb() unconditionally attempts to acquire rdtgroup_mutex and deadlock occurs. Since mount failure resulting from kernfs_get_tree() already calls the resctrl fs unmount handler (rdt_kill_sb()) let both call the same helper to make it clear both paths perform the same cleanup. Call kernfs_get_tree() outside of locks. If kernfs_get_tree() fails and ctx->kfc.new_sb_created is set, then rdt_kill_sb() has already been called and no further cleanup is needed. kernfs_get_tree() may set ctx->kfc.new_sb_created and then fail to obtain an inode for the new kn, causing the rdt_kill_sb() path to run with one fewer reference than required for the root to remain accessible in kernfs_kill_sb(). Add an extra hold on rdtgroup_default.kn to defend against this scenario and ensure the root can be dereferenced safely from kernfs_kill_sb(). Dropping locks before kernfs_get_tree() creates a window where CPU hotplug callbacks can race with the mount operation. Specifically, an online event observing resctrl_mounted == true could concurrently append directories to the unactivated kernfs tree, allocate mon_data structures, and arm background workers. This concurrency is safe because the mount has not yet returned to the VFS, meaning userspace cannot interact with these transient files. If kernfs_get_tree() subsequently fails, the standard resctrl_unmount() teardown safely manages the concurrent modifications: any dynamically generated kernfs nodes are removed, and the associated memory is freed. Any background workers spawned by the hotplug event will naturally exit without re-arming when they acquire rdtgroup_mutex and observe resctrl_mounted == false. Fixes: 5ff193fbde20 ("x86/intel_rdt: Add basic resctrl filesystem support") Closes: https://sashiko.dev/#/patchset/20260429184858.36423-1-tony.luck%40intel.com [1] Reported-by: Sashiko <sashiko-bot@kernel.org> Co-developed-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: Chen Yu <yu.c.chen@intel.com> Link: https://patch.msgid.link/fe701825d7f538a6bbac6732230004050300c93e.1783963505.git.reinette.chatre@intel.com
2026-07-13fs/resctrl: Move functions to avoid forward references in subsequent fixesTony Luck
rdt_get_tree() manages resctrl fs mount and rdt_kill_sb() manages resctrl fs unmount. There is significant overlap between error cleanup during resctrl mount failure and cleanup on resctrl unmount yet the cleanup is not done consistently in these two flows. Pull some cleanup functions before rdt_get_tree() in preparation for a new helper that can be shared between mount and unmount. Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Ben Horgan <ben.horgan@arm.com> Link: https://patch.msgid.link/af10101be95679e1d69ce4efc3edf980a6cc37cc.1783963505.git.reinette.chatre@intel.com
2026-07-13x86,fs/resctrl: Document safe RCU list traversalReinette Chatre
rdt_resource::ctrl_domains and rdt_resource::mon_domains are RCU lists with entries added and removed by architecture from CPU hotplug callbacks that are run with cpus_write_lock() held. These lists can be traversed safely from resctrl fs by either holding cpus_read_lock() or relying on an RCU read-side critical section. resctrl fs traversals of rdt_resource::ctrl_domains and rdt_resource::mon_domains are done using list_for_each_entry() with cpus_read_lock() held. Similarly, x86 architecture callbacks use list_for_each_entry() expecting that resctrl fs makes the call with cpus_read_lock() held. Inconsistently, a lockdep_assert_cpus_held() precedes the list_for_each_entry() call with varying distance to document this safe RCU list traversal. In preparation for an upcoming traversal of rdt_resource::ctrl_domains that needs to be done from RCU read-side critical section there is a requirement for developers to always know exactly in which context the list is being traversed. Replace the list_for_each_entry() traversals of RCU list with list_for_each_entry_rcu() to document that an RCU list is being traversed while making use of the built-in lockdep expression that additionally documents that it is cpus_read_lock() that enables the list to be traversed from non-RCU protection. Only revert to documenting the safety of traversal using a comment when lockdep does not have needed visibility in functions called via smp_call*(). The lockdep expression within list_for_each_entry_rcu() depends on RCU_EXPERT that is not set in a typical debug kernel so keep the existing lockdep_assert_cpus_held() that is active with CONFIG_LOCKDEP=y found in typical debug kernel. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://patch.msgid.link/d9373f8da8ffde667740e186ffc96ab69628ac9a.1783963505.git.reinette.chatre@intel.com
2026-07-13Merge tag 'nfsd-7.2-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux Pull nfsd fix from Chuck Lever: - Fix a use-after-free when unlocking a filesystem * tag 'nfsd-7.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: NFSD: Prevent post-shutdown use-after-free in NFSD_CMD_UNLOCK_FILESYSTEM
2026-07-13smb: client: reject overlapping data areas in SMB2 responsesShoichiro Miyamoto
Commit 53b7c271f06b ("smb: client: restrict implied bcc[0] exemption to responses without data area") restricted the implied bcc[0] length exception to responses without a data area. However, the overlap handling in __smb2_calc_size() clears data_length, which can make an invalid response appear to have no data area and so qualify for the exception. Track data area overlap separately and reject such responses before applying the length compatibility exceptions. Fixes: 53b7c271f06b ("smb: client: restrict implied bcc[0] exemption to responses without data area") Cc: stable@vger.kernel.org Signed-off-by: Shoichiro Miyamoto <shoichiro.miyamoto@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-13smb/client: refresh allocation after EOF-extending fallocateHuiwen He
Before this change, xfstests generic/496 was not supported on ksmbd: generic/496 ... [not run] fallocated swap not supported here ksmbd handles SetEOF as truncate, so EOF extension alone does not allocate backing blocks. A fallocated swapfile can therefore still look sparse to swapon. Request allocation for EOF-extending fallocate ranges that can be represented by FILE_ALLOCATION_INFORMATION, and refresh the allocation state afterwards. With this change, xfstests generic/496 and generic/701 pass on ksmbd. However, Samba "strict allocate = no" now exposes the real generic/701 failure: the old pass came from inflated local i_blocks, not from server allocation. generic/213 also fails in that case because an oversized allocation request may not return ENOSPC. Signed-off-by: Huiwen He <hehuiwen@kylinos.cn> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-13smb/client: emulate small EOF-extending mode 0 fallocate rangesHuiwen He
When a mode 0 fallocate extends EOF from 1G to 2G + 1M, the client currently sends SetEOF for 2G + 1M. This can make fallocate return success without allocating the requested range, or allocate extra space before that range. For example, on a fresh file: xfs_io -f \ -c "falloc 0 1G" \ -c "falloc 2G 1M" \ -c "truncate 3G" test The second fallocate should allocate [2G, 2G + 1M), leaving [1G, 2G) as a hole. Before this change, the result depended on the server allocation policy. With Samba "strict allocate = no", SetEOF could return success without allocating [2G, 2G + 1M). With "strict allocate = yes": # filefrag -v test [0, 1G) allocated [1G, 2G) allocated unexpectedly [2G, 2G + 1M) allocated SMB cannot allocate that arbitrary range, so write zeroes to small EOF-extending ranges instead. Limit this to 1 MiB to bound the client-side I/O cost. With "strict allocate = no", the requested range [2G, 2G + 1M) is allocated by the writes. With "strict allocate = yes": # filefrag -v test [0, 1G) allocated [1G, 2G) hole [2G, 2G + 1M) allocated This fixes the small EOF-extending range case exercised by generic/213. Signed-off-by: Huiwen He <hehuiwen@kylinos.cn> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-13smb/client: reduce fallocate zero buffer allocationHuiwen He
The fallocate emulation allocates a 1 MiB zero-filled buffer even though each SMB2_write request is limited to SMB2_MAX_BUFFER_SIZE, which is 64 KiB. A high-order 1 MiB allocation is more likely to fail on a fragmented system. Allocate only the smaller of the requested range and SMB2_MAX_BUFFER_SIZE, and reuse that zero-filled buffer for every write request. Also reject a successful write that makes no progress to avoid looping indefinitely. This reduces the contiguous allocation required by fallocate emulation without changing the written data or range semantics. Signed-off-by: Huiwen He <hehuiwen@kylinos.cn> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-13smb/client: handle overlapping allocated ranges in fallocateHuiwen He
smb3_simple_fallocate_range() can skip holes when an allocated range returned by the server starts before the current fallocate offset. The skipped hole is not zero-filled, but fallocate still returns success. A later write to that hole may therefore fail with ENOSPC. The function queries allocated ranges so that it can preserve existing contents and write zeroes only into holes. However, the server may return a range that starts before the current fallocate offset. For example, assume the fallocate request is [100, 400) and the only allocated range returned by the server is [0, 200): Request: [100, 400) Server range: [ 0, 200) allocated Correct: [100, 200) allocated data, skip [200, 400) hole, zero-fill Current: [100, 300) skipped [300, 400) zero-filled afterwards The current code adds the full server range length, 200, to the current offset 100 and moves to 300. As a result, the hole in [200, 300) is skipped without being zero-filled. Fix this by advancing only over the part of the allocated range that overlaps the current fallocate offset. Ignore ranges that end before the current offset and reject ranges whose end offset overflows. This also prevents a malformed range length from causing an out-of-bounds zero-buffer read. Fixes: 966a3cb7c7db ("cifs: improve fallocate emulation") Signed-off-by: Huiwen He <hehuiwen@kylinos.cn> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-13smb/client: refresh allocation size after duplicate extentsHuiwen He
FSCTL_DUPLICATE_EXTENTS_TO_FILE changes the target file extents on the server, but the client does not refresh the target AllocationSize/i_blocks. Callers can observe or use the wrong st_blocks value immediately after the clone, before a later attribute revalidation corrects it. For example, create a reflinked file with a leading hole: xfs_io -f -c "pwrite -S 0x61 0 64k" src touch dst chmod 600 dst xfs_io -c "reflink src 0 1m 64k" dst mkswap dst swapon dst The file still has a hole after mkswap: /mnt/scratch/dst: [0..7]: allocated [8..2047]: hole [2048..2175]: allocated The server also reports only the allocated ranges: server dst size=1114112 blocks=144 but the client reported EOF-derived blocks: client dst size=1114112 blocks=2176 and swapon succeeded: swapon_result=success /mnt/scratch/dst 1.1M 0B -1 So EOF-derived i_blocks can let a sparse reflinked file pass the CIFS swapfile hole check. Fix this by querying FILE_ALL_INFORMATION on the target handle after a successful duplicate extents request. Update i_blocks from AllocationSize and keep the refreshed target inode attributes valid so a following stat does not immediately revalidate again. If the query fails, mark the cached inode attributes stale so a later getattr can refresh them. This also fixes the xfstests generic/370 regression introduced by the i_blocks accounting change, as tested on a Samba "vfs objects = btrfs" share. Fixes: 99cd0a6eeb6c ("smb/client: do not account EOF extension as allocation") Signed-off-by: Huiwen He <hehuiwen@kylinos.cn> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-13smb: client: use kvzalloc() for megabyte buffer in simple fallocateFredric Cover
Currently in smb3_simple_fallocate_range(), a 1 MB buffer is allocated using kzalloc(). Under heavy memory fragmentation, a contiguous 1 MB block of physical memory (an order-8 allocation) may not be available, causing the allocation to fail. This failure was observed during xfstests generic/013 on a 4GB RAM test machine running fsstress: fsstress: page allocation failure: order:8, mode:0x40dc0(GFP_KERNEL|__GFP_ZERO|__GFP_COMP), nodemask=(null),cpuset=/,mems_allowed=0 Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 warn_alloc+0x163/0x190 __alloc_pages_slowpath.constprop.0+0x71b/0x12f0 __alloc_frozen_pages_noprof+0x2f6/0x340 alloc_pages_mpol+0xb6/0x170 ___kmalloc_large_node+0xb3/0xd0 __kmalloc_large_noprof+0x1e/0xc0 smb3_simple_falloc.isra.0+0x62b/0x960 cifs_fallocate+0xed/0x180 vfs_fallocate+0x165/0x3c0 __x64_sys_fallocate+0x48/0xa0 do_syscall_64+0xe1/0x640 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> Node 0 Normal: 3375*4kB ... 7*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB Since this scratch buffer does not require physically contiguous memory, switch the allocation to kvzalloc(). This retains the performance benefits of kmalloc() under normal conditions, while gracefully falling back to virtually contiguous memory when physical allocation fails. Fixes: 966a3cb7c7db ("cifs: improve fallocate emulation") Cc: stable@vger.kernel.org Signed-off-by: Fredric Cover <fredric.cover.lkernel@gmail.com> Tested-by: Fredric Cover <fredric.cover.lkernel@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2026-07-13isofs: fix out-of-bounds page array access on empty zisofs blockXiang Mei
zisofs_uncompress_block()'s empty-block fast path returns pcount << PAGE_SHIFT, ignoring the incoming poffset, unlike the decompression path which returns bytes produced relative to poffset. zisofs_fill_pages() uses that return to advance its page cursor, so when the zisofs block size is below PAGE_SIZE and a sub-page block leaves poffset partway into a page, a following empty block over-counts and advances pages[] one element past its end, after which "if (poffset && *pages)" reads pages[1] out of bounds. rock.c only rejects a block-size shift > 17, so a crafted "ZF" Rock Ridge record can set it below PAGE_SHIFT; the bug is reached by an ordinary read() of a compressed file on such a mounted ISO9660 image. Return the byte count relative to poffset and zero only [poffset, PAGE_SIZE) of the first page, matching the decompression path. The page-aligned case (poffset == 0) is unaffected. BUG: KASAN: slab-out-of-bounds in zisofs_read_folio (fs/isofs/compress.c:290) Read of size 8 at addr ffff88800f5eac48 by task exploit/142 zisofs_read_folio (fs/isofs/compress.c:290) read_pages (mm/readahead.c:184) ... filemap_read (mm/filemap.c:2814) vfs_read (fs/read_write.c:574) __x64_sys_pread64 (fs/read_write.c:769) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) The buggy address is located 0 bytes to the right of the allocated 8-byte region in the kmalloc-8 cache Fixes: 59bc055211b8 ("zisofs: Implement reading of compressed files when PAGE_CACHE_SIZE > compress block size") Reported-by: Weiming Shi <bestswngs@gmail.com> Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Xiang Mei <xmei5@asu.edu> Link: https://patch.msgid.link/20260712234150.3213467-1-xmei5@asu.edu Signed-off-by: Jan Kara <jack@suse.cz>
2026-07-13erofs: hide "cache_strategy=" for plain filesystemsGao Xiang
"cache_strategy=" is meaningless and confusing on unencoded EROFS filesystems; gate it on compressed images only since it's now possible after commit 7cef3c834194 ("erofs: separate plain and compressed filesystems formally"). Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
2026-07-12xfs: fix null pointer dereference in tracepointAndrey Albershteyn
If dfp is not NULL we exit early here, when dfp is NULL it's allocated in xfs_defer_alloc() but not assigned. The tracepoint tries to dereference members of dfp struct. Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org> Cc: stable@vger.kernel.org # v6.8 Fixes: 3f3cec031099c3 ("xfs: force small EFIs for reaping btree extents") Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Carlos Maiolino <cem@kernel.org>
2026-07-12RDMA: Change capability fields in ib_device_attr from int to u32Erni Sri Satya Vennela
The capability counter fields in struct ib_device_attr are declared as signed int, but these values are inherently non-negative. Drivers maintain their cached caps as u32 and assign them directly into these int fields; if a cap exceeds INT_MAX the implicit narrowing yields a negative value visible to the IB core. Change the signed int capability fields to u32 to match the underlying nature of the data. Also update consumers across the IB core, ULPs, NVMe-oF target, RDS, and NFS/RDMA so the new u32 values are not forced back through signed int or u8 via min()/min_t() or narrowing local variables. The nvmet-rdma consumer of max_srq clamps it against ib_device.num_comp_vectors, which stays a signed int, so that site uses min_t() instead of min() to handle the signed/unsigned mismatch. Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com> Link: https://patch.msgid.link/20260709055211.2498307-1-ernis@linux.microsoft.com Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Stefan Metzmacher <metze@samba.org> # smbdirect Signed-off-by: Leon Romanovsky <leon@kernel.org>