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2026-06-04mm: track DONTCACHE dirty pages per bdi_writebackJeff Layton
Add a per-wb WB_DONTCACHE_DIRTY counter that tracks the number of dirty pages with the dropbehind flag set (i.e., pages dirtied via RWF_DONTCACHE writes). Increment the counter alongside WB_RECLAIMABLE in folio_account_dirtied() when the folio has the dropbehind flag set, and decrement it in folio_clear_dirty_for_io() and folio_account_cleaned(). Also decrement it when a non-DONTCACHE lookup atomically clears the dropbehind flag on a dirty folio in __filemap_get_folio_mpol(), using folio_test_clear_dropbehind() to prevent concurrent lookups from double-decrementing the counter, and guarding the decrement with mapping_can_writeback() to match the increment path. Transfer the counter alongside WB_RECLAIMABLE in inode_do_switch_wbs() so that the stat is properly migrated when an inode switches cgroup writeback domains. The counter will be used by the writeback flusher to determine how many pages to write back when expediting writeback for IOCB_DONTCACHE writes, without flushing the entire BDI's dirty pages. Suggested-by: Jan Kara <jack@suse.cz> Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://patch.msgid.link/20260511-dontcache-v7-2-2848ddce8090@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-04libfs: drop redundant SB_I_NOEXEC/SB_I_NODEV in init_pseudo() callersJohn Hubbard
init_pseudo() now sets SB_I_NOEXEC and SB_I_NODEV by default, so the per-caller assignments are redundant. Drop them. Signed-off-by: John Hubbard <jhubbard@nvidia.com> Link: https://patch.msgid.link/20260604025315.245910-3-jhubbard@nvidia.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-04libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()John Hubbard
Since commit 1e7ab6f67824 ("anon_inode: rework assertions"), path_noexec() warns when an anonymous-inode file is mmap'd from a superblock that has not set SB_I_NOEXEC. dma-buf backs its files this way and never set the flag, so mmap of any exported buffer trips the warning on a CONFIG_DEBUG_VFS=y kernel: WARNING: CPU: 11 PID: 121813 at fs/exec.c:118 path_noexec+0x47/0x50 do_mmap+0x2b5/0x680 vm_mmap_pgoff+0x129/0x210 ksys_mmap_pgoff+0x177/0x240 __x64_sys_mmap+0x33/0x70 init_pseudo() sets up internal SB_NOUSER mounts that are never path-reachable. Set both flags here so every pseudo filesystem gets them by default instead of each caller setting them. SB_I_NODEV is inert for unreachable mounts. SB_I_NOEXEC has one visible effect: an executable mapping of a pseudo-fs fd, such as a dma-buf, now fails with -EPERM, which is the invariant the assertion enforces. No in-tree caller maps these executable. Reproduce on CONFIG_DEBUG_VFS=y: make -C tools/testing/selftests/dmabuf-heaps sudo ./tools/testing/selftests/dmabuf-heaps/dmabuf-heap -t system Fixes: 1e7ab6f67824 ("anon_inode: rework assertions") Suggested-by: Christoph Hellwig <hch@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: John Hubbard <jhubbard@nvidia.com> Link: https://patch.msgid.link/20260604025315.245910-2-jhubbard@nvidia.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-04iomap: avoid potential null folio->mapping deref during error reportingJoanne Koong
When a buffered read fails, iomap_finish_folio_read() reports the error with fserror_report_io(folio->mapping->host, ...). This is called after ifs->read_bytes_pending has been decremented by the bytes attempted to be read. For a folio split across multiple read completions, the folio is only guaranteed to stay locked while read_bytes_pending > 0. Once iomap_finish_folio_read() decrements read_bytes_pending, another in-flight read can complete and end the read on the folio, which unlocks it. This allows truncate logic to run and detach the folio (set folio->mapping to NULL). The error reporting path then can dereference a NULL folio->mapping. As reported by Sam Sun, this is the race that can occur: CPU0: failed completion CPU1: final completion CPU2: truncate ----------------------- ---------------------- -------------- read_bytes_pending -= len finished = false /* preempted before fserror_report_io() */ read_bytes_pending -= len finished = true folio_end_read() truncate clears folio->mapping fserror_report_io( folio->mapping->host, ...) ^ NULL deref Fix this by reporting the error first before decrementing ifs->read_bytes_pending. Fixes: a9d573ee88af ("iomap: report file I/O errors to the VFS") Cc: stable@vger.kernel.org Reported-by: Sam Sun <samsun1006219@gmail.com> Closes: https://lore.kernel.org/linux-fsdevel/CAEkJfYPhWdd59RKmuNLJg-bkypHz7xiOwaWyNVu3A8CUqQCnvg@mail.gmail.com/ Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Link: https://patch.msgid.link/20260604011858.2297561-1-joannelkoong@gmail.com Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-04fhandle: fix UAF due to unlocked ->mnt_ns read in may_decode_fh()Jann Horn
may_decode_fh() accesses mount::mnt_ns without holding any locks; that means the mount can concurrently be unmounted, and the mnt_namespace can concurrently be freed after an RCU grace period. This race can happens as follows, assuming that the mount point was created by open_tree(..., OPEN_TREE_CLONE): thread 1 thread 2 RCU __do_sys_open_by_handle_at do_handle_open handle_to_path may_decode_fh is_mounted [mount::mnt_ns access] [mount::mnt_ns access] __do_sys_close fput_close_sync __fput dissolve_on_fput umount_tree class_namespace_excl_destructor namespace_unlock free_mnt_ns mnt_ns_tree_remove call_rcu(mnt_ns_release_rcu) mnt_ns_release_rcu mnt_ns_release kfree [mnt_namespace::user_ns access] **UAF** Fix it by taking rcu_read_lock() around the mount::mnt_ns access, like in __prepend_path(). Additionally, document the semantics of mount::mnt_ns, and use WRITE_ONCE() for writers that can race with lockless readers. This bug is unreachable unless one of the following is set: - CONFIG_PREEMPTION - CONFIG_RCU_STRICT_GRACE_PERIOD because it requires an RCU grace period to happen during a syscall without an explicit preemption. This doesn't seem to have interesting security impact; worst-case, it could leak the result of an integer comparison to userspace (from the level check in cap_capable()), cause an endless loop, or crash the kernel by dereferencing an invalid address. Fixes: 620c266f3949 ("fhandle: relax open_by_handle_at() permission checks") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn <jannh@google.com> Link: https://patch.msgid.link/20260603-vfs-fhandle-uaf-fix-v2-1-d05db76a5084@google.com Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-03fs/ntfs3: validate lcns_follow in log_replay conversionKonstantin Komarov
log_replay() converts DIR_PAGE_ENTRY_32 records into DIR_PAGE_ENTRY records when replaying version 0 restart tables. During this conversion, the memmove() length is derived directly from the on-disk lcns_follow field: memmove(&dp->vcn, &dp0->vcn_low, 2 * sizeof(u64) + le32_to_cpu(dp->lcns_follow) * sizeof(u64)); check_rstbl() validates restart table structure, but does not constrain per-entry lcns_follow values relative to the entry size. A malformed filesystem image can provide an oversized lcns_follow value, causing the conversion memmove() to access memory beyond the bounds of the allocated restart table buffer. The same field is later used to bound iteration over page_lcns[], so validating lcns_follow during conversion also prevents downstream out-of-bounds access from the same malformed metadata. Compute the maximum valid lcns_follow from the already-validated restart table entry size and reject entries that exceed this bound. Reuse the existing t16/t32 scratch variables already declared in log_replay() to avoid introducing new declarations. Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Signed-off-by: Pavitra Jha <jhapavitra98@gmail.com> [almaz.alexandrovich@paragon-software.com: fixed the conflicts] Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-03fs/ntfs3: bound copy_lcns dp->page_lcns[] index in analysis passMichael Bommarito
In log_replay()'s analysis pass, after find_dp() returns a valid DIR_PAGE_ENTRY for the (target_attr, target_vcn) tuple, the copy_lcns block walks lrh->lcns_follow further entries: t16 = le16_to_cpu(lrh->lcns_follow); for (i = 0; i < t16; i++) { size_t j = (size_t)(le64_to_cpu(lrh->target_vcn) - le64_to_cpu(dp->vcn)); dp->page_lcns[j + i] = lrh->page_lcns[i]; } find_dp() only validates that target_vcn falls within [dp->vcn, dp->vcn + dp->lcns_follow), i.e., that the FIRST cluster is covered. The walk through the further entries is not bounded against dp->lcns_follow. For a malformed LRH where target_vcn = dp->vcn + dp->lcns_follow - 1 and lrh->lcns_follow > 1, the i > 0 writes overflow the dp's allocated page_lcns[] array. Add the missing j + lrh->lcns_follow <= dp->lcns_follow guard. Reproduced under UML+KASAN on mainline 8d90b09e6741 as a slab-out-of-bounds write of size 8 from log_replay+0x68d4 on the mount path. This is distinct from Pavitra Jha's 2026-05-02 patch ("fs/ntfs3: validate lcns_follow in log_replay conversion", <20260502154252.164586-1-jhapavitra98@gmail.com>) which addresses the separate version-0 dirty-page-table conversion path's memmove(&dp->vcn, ...) call. The two fixes are complementary; both should land. Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> [almaz.alexandrovich@paragon-software.com: clang-formatted the changes, fixed conflicts] Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-03fs/ntfs3: bound DeleteIndexEntryAllocation memmove lengthKonstantin Komarov
In do_action()'s DeleteIndexEntryAllocation case, e->size comes from an on-disk INDEX_BUFFER entry. When e->size makes e + e->size point past hdr + hdr->used, PtrOffset(e1, Add2Ptr(hdr, used)) returns a negative ptrdiff_t that is silently cast to a quasi-infinite size_t when passed to memmove(). The memmove then walks past the destination buffer. The sibling DeleteIndexEntryRoot case at fslog.c:3540-3543 already carries the corresponding guard: if (PtrOffset(e1, Add2Ptr(hdr, used)) < esize || Add2Ptr(e, esize) > Add2Ptr(lrh, rec_len) || used + esize > le32_to_cpu(hdr->total)) { goto dirty_vol; } Apply the same shape to the allocation-path case. Also reject esize == 0: memmove(e, e, ...) is a no-op and leaves hdr->used unchanged, hiding a malformed entry from the existing check_index_header() walk. Reproduced under UML+KASAN on mainline 8d90b09e6741 by mounting a crafted NTFS image: the unguarded memmove takes a length of 0xffffffffffffff00 and the kernel oopses in memmove+0x81/0x1a0 on the do_action+0x36a2 frame. Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> [almaz.alexandrovich@paragon-software.com: clang-formatted the changes] Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-03fs/ntfs3: bound attr_off in UpdateResidentValue against data_offKonstantin Komarov
In do_action()'s UpdateResidentValue case (fslog.c:3307), lrh->attr_off and lrh->redo_len come from the on-disk LRH. When they satisfy aoff + dlen < attr->res.data_off, the assignment attr->res.data_size = cpu_to_le32(aoff + dlen - data_off); underflows to ~4 GiB (e.g. 0xFFFFFFF9 when aoff=0x10, dlen=1, data_off=0x18). Subsequent code that reads attr->res.data_size to walk the resident attribute payload would then read up to 4 GiB past the 1024-byte MFT record allocation. The existing mi_enum_attr() defense in fs/ntfs3/record.c:287 catches the corrupted data_size on the next attribute walk and fails the mount, but only on the path that walks all attributes. A read site that picks an attribute by name and reads its data_size without re-validating is not covered. Validate aoff against data_off and asize at the source. Reproduced under UML+KASAN on mainline 8d90b09e6741 via pr_warn-only probe: with aoff=0x10 and data_off=0x18, the post-assignment data_size is 0xfffffff9 (mount then fails at -22 from mi_enum_attr). Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> [almaz.alexandrovich@paragon-software.com: clang-formatted the changes] Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-03ext4: improve str2hashbuf by processing 4-byte chunks and removing function ↵Guan-Chun Wu
pointers The original byte-by-byte implementation with modulo checks is less efficient. Refactor str2hashbuf_unsigned() and str2hashbuf_signed() to process input in explicit 4-byte chunks instead of using a modulus-based loop to emit words byte by byte. Additionally, the use of function pointers for selecting the appropriate str2hashbuf implementation has been removed. Instead, the functions are directly invoked based on the hash type, eliminating the overhead of dynamic function calls. Performance test (x86_64, Intel Core i7-10700 @ 2.90GHz, average over 10000 runs, using kernel module for testing): len | orig_s | new_s | orig_u | new_u ----+--------+-------+--------+------- 1 | 70 | 71 | 63 | 63 8 | 68 | 64 | 64 | 62 32 | 75 | 70 | 75 | 63 64 | 96 | 71 | 100 | 68 255 | 192 | 108 | 187 | 84 This change improves performance, especially for larger input sizes. Signed-off-by: Guan-Chun Wu <409411716@gms.tku.edu.tw> Link: https://patch.msgid.link/20260531080019.3794809-3-409411716@gms.tku.edu.tw Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: add Kunit coverage for directory hash computationGuan-Chun Wu
Introduce Kunit tests for fs/ext4/hash.c to verify ext4fs_dirhash() across the legacy, half-MD4, and TEA hash variants. The tests cover empty, seeded hashing, and non-ASCII name handling. They also verify error paths, including invalid hash versions and SipHash without a configured key, and check that the signed and unsigned hash variants differ on non-ASCII input as expected. When CONFIG_UNICODE is enabled, the tests further verify casefolded-name hashing and the fallback behavior for invalid input. Co-developed-by: Chen Hao Yu <edward062254@gmail.com> Signed-off-by: Chen Hao Yu <edward062254@gmail.com> Signed-off-by: Guan-Chun Wu <409411716@gms.tku.edu.tw> Link: https://patch.msgid.link/20260531080019.3794809-2-409411716@gms.tku.edu.tw Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: fast commit: export snapshot stats in fc_infoLi Chen
Snapshot-based fast commit can fall back when the commit-time snapshot cannot be built (e.g. extent status cache misses). It is useful to quantify the updates-locked window and to see why snapshotting failed. Add best-effort snapshot counters to the ext4 superblock and extend /proc/fs/ext4/<sb_id>/fc_info to report the number of snapshotted inodes and ranges, snapshot failure reasons, and the average/max time spent with journal updates locked. Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Link: https://patch.msgid.link/20260515091829.194810-8-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: fast commit: add lock_updates tracepointLi Chen
Commit-time fast commit snapshots run under jbd2_journal_lock_updates(), so it is useful to quantify the time spent with updates locked and to understand why snapshotting can fail. Add a new tracepoint, ext4_fc_lock_updates, reporting the time spent in the updates-locked window along with the number of snapshotted inodes and ranges. Record the first snapshot failure reason in a stable snap_err field for tooling. Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://patch.msgid.link/20260515091829.194810-7-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: fast commit: avoid i_data_sem by dropping ext4_map_blocks() in snapshotsLi Chen
Commit-time snapshots run under jbd2_journal_lock_updates(), so the work done there must stay bounded. The snapshot path still used ext4_map_blocks() to build data ranges. This can take i_data_sem and pulls the mapping code into the snapshot logic. Build inode data range snapshots from the extent status tree instead. The extent status tree is a cache, not an authoritative source. If the needed information is missing or unstable (e.g. delayed allocation), treat the transaction as fast commit ineligible and fall back to full commit. Also cap the number of inodes and ranges snapshotted per fast commit and allocate range records from a dedicated slab cache. The inode pointer array is allocated outside the updates-locked window. Testing: QEMU/KVM guest, virtio-pmem + dax, ext4 -O fast_commit, mounted dax,noatime. Ran python3 500x {4K write + fsync}, fallocate 256M, and python3 500x {creat + fsync(dir)} without lockdep splats or errors. Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Link: https://patch.msgid.link/20260515091829.194810-6-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: fast commit: avoid self-deadlock in inode snapshottingLi Chen
ext4_fc_snapshot_inodes() used igrab()/iput() to pin inodes while building commit-time snapshots. With ext4_fc_del() waiting for EXT4_STATE_FC_COMMITTING, iput() can trigger ext4_clear_inode()->ext4_fc_del() in the commit thread and deadlock waiting for the fast commit to finish. ext4_fc_del() also has to re-check EXT4_STATE_FC_COMMITTING after waiting on EXT4_STATE_FC_FLUSHING_DATA. The commit thread clears FLUSHING_DATA before it sets COMMITTING, so a waiter woken from the flush wait must not delete the inode based on an old COMMITTING check. Avoid taking extra references. Collect inode pointers under s_fc_lock and rely on EXT4_STATE_FC_COMMITTING to pin inodes until ext4_fc_cleanup() clears the bit. Also set EXT4_STATE_FC_COMMITTING for create-only inodes referenced from the dentry update queue, and wake up waiters when ext4_fc_cleanup() clears the bit. Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Link: https://patch.msgid.link/20260515091829.194810-5-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: fast commit: avoid waiting for FC_COMMITTINGLi Chen
ext4_fc_track_inode() can be called while holding i_data_sem (e.g. fallocate). Waiting for EXT4_STATE_FC_COMMITTING in that case risks an ABBA deadlock: i_data_sem -> wait(FC_COMMITTING) vs FC_COMMITTING -> wait(i_data_sem) in the commit task. Now that fast commit snapshots inode state at commit time, updates during log writing do not need to block. Drop the wait and lockdep assertion in ext4_fc_track_inode(), and make ext4_fc_del() wait for FC_COMMITTING so an inode cannot be removed while the commit thread is still using it. When an inode is modified during a fast commit, mark it with EXT4_STATE_FC_REQUEUE so cleanup keeps it queued for the next fast commit. This is needed because jbd2_fc_end_commit() invokes the cleanup callback with tid == 0, so tid-based requeue logic would requeue every inode. Testing: tracepoint ext4:ext4_fc_commit_stop with two fsyncs in the same transaction. nblks is the number of journal blocks written for that fast commit. Before this change, the second fsync still wrote almost the same fast commit log (nblks 10->9), because tid == 0 in jbd2_fc_end_commit() caused the tid-based requeue logic to keep all inodes queued. After this change, only inodes modified during the commit are requeued, and the second fsync wrote a nearly empty fast commit (nblks 10->1). Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Link: https://patch.msgid.link/20260515091829.194810-4-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: lockdep: handle i_data_sem subclassing for special inodesLi Chen
Fast commit can hold s_fc_lock while writing journal blocks. Mapping the journal inode can take its i_data_sem. Normal inode update paths can take a data inode i_data_sem and then s_fc_lock, which makes lockdep report a circular dependency. lockdep treats all i_data_sem instances as one lock class and cannot distinguish the journal inode i_data_sem from a regular inode i_data_sem. The journal inode is not tracked by fast commit and no FC waiters ever depend on it, so this is not a real ABBA deadlock. Assign the journal inode a dedicated i_data_sem lockdep subclass to avoid the false positive. Inode cache objects can be recycled, so also reset i_data_sem to I_DATA_SEM_NORMAL when allocating an ext4 inode. Otherwise a new inode may inherit an old subclass (journal/quota/ea) and trigger lockdep warnings. Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Link: https://patch.msgid.link/20260515091829.194810-3-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: fast commit: snapshot inode state before writing logLi Chen
Fast commit writes inode metadata and data range updates after unlocking journal updates. New handles can start at that point, so the log writing path must not look at live inode state. Add a commit-time per-inode snapshot and populate it while journal updates are locked and existing handles are drained. Store the snapshot behind ext4_inode_info->i_fc_snap so ext4_inode_info only grows by one pointer. The snapshot contains a copy of the on-disk inode plus the data range records needed for fast commit TLVs. Snapshotting runs under jbd2_journal_lock_updates(). Avoid triggering I/O there by using ext4_get_inode_loc_noio() and falling back to full commit if the inode table block is not present or not uptodate. Log writing then only serializes the snapshot, so it no longer needs to call ext4_map_blocks() and take i_data_sem under s_fc_lock. The snapshot is installed and freed under s_fc_lock and is released from fast commit cleanup and inode eviction. Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Link: https://patch.msgid.link/20260515091829.194810-2-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03jbd2: fix integer underflow in jbd2_journal_initialize_fast_commit()Junrui Luo
jbd2_journal_initialize_fast_commit() validates journal capacity by checking (journal->j_last - num_fc_blks < JBD2_MIN_JOURNAL_BLOCKS). Both j_last and num_fc_blks are unsigned, so when num_fc_blks exceeds j_last the subtraction wraps to a large value, bypassing the bounds check. The resulting underflow corrupts j_last, j_fc_first, and j_free, leading to journal abort. Fix by checking num_fc_blks against j_last before the subtraction, returning -EFSCORRUPTED. Fixes: 6866d7b3f2bb ("ext4 / jbd2: add fast commit initialization") Reported-by: Yuhao Jiang <danisjiang@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo <moonafterrain@outlook.com> Fixes: e029c5f27987 ("ext4: make num of fast commit blocks configurable") Reviewed-by: Baokun Li <libaokun@linux.alibaba.com> Fixes: e029c5f279872 ("ext4: make num of fast commit blocks configurable") Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/SYBPR01MB7881663C927DE9D7BBF4D1DFAF062@SYBPR01MB7881.ausprd01.prod.outlook.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03ext4: fix fast commit wait/wake bit mapping on 64-bitLi Chen
On 64-bit, ext4 dynamic inode states live in the upper half of i_flags, and ext4_test_inode_state() applies the corresponding +32 offset. The fast-commit wait and wake paths open-coded the wait key with the raw EXT4_STATE_* value. Add small helpers for the state wait word and bit, and use them for the FC_COMMITTING and FC_FLUSHING_DATA waits so the wait key follows the same mapping as the state helpers. Fixes: 857d32f26181 ("ext4: rework fast commit commit path") Reported-by: Sashiko AI review <sashiko-bot@kernel.org> Signed-off-by: Li Chen <chenl311@chinatelecom.cn> Reviewed-by: Baokun Li <libaokun@linux.alibaba.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://patch.msgid.link/20260513085818.552432-1-me@linux.beauty Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03jbd2: check for aborted handle in jbd2_journal_dirty_metadata()Deepanshu Kartikey
jbd2_journal_dirty_metadata() unconditionally dereferences handle->h_transaction at function entry to obtain the journal pointer: transaction_t *transaction = handle->h_transaction; journal_t *journal = transaction->t_journal; However, h_transaction may legitimately be NULL for an aborted handle. The is_handle_aborted() helper in include/linux/jbd2.h explicitly treats !h_transaction as one of the aborted states: if (handle->h_aborted || !handle->h_transaction) return 1; Every other entry point in fs/jbd2/transaction.c (jbd2_journal_get_{write,undo,create}_access, jbd2_journal_extend, jbd2_journal_restart, jbd2_journal_stop, etc.) guards against this with an is_handle_aborted() check before any dereference of h_transaction. jbd2_journal_dirty_metadata() was missing this guard. This is reachable from ocfs2's xattr code. ocfs2_xa_set() intentionally falls through to ocfs2_xa_journal_dirty() even after ocfs2_xa_prepare_entry() fails, on the assumption that the buffer needs to be journaled to record any partial modifications (see the comment above the out_dirty label in fs/ocfs2/xattr.c). If the failure was caused by the journal being aborted -- e.g. an underlying I/O error during a sub-operation such as __ocfs2_remove_xattr_range() -- the handle's h_transaction has been cleared by the abort path, and the unconditional deref in jbd2_journal_dirty_metadata() becomes a NULL deref. Reproduced by syzbot with a crafted ocfs2 image where I/O against the loop device backing the mount is sabotaged via LOOP_SET_STATUS64 between two setxattr() calls, causing the second setxattr (which truncates an external xattr value) to abort the journal mid-flight: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000 KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: jbd2_journal_dirty_metadata+0x4a/0xd30 fs/jbd2/transaction.c:1520 Call Trace: ocfs2_journal_dirty+0x130/0x700 fs/ocfs2/journal.c:831 ocfs2_xa_journal_dirty fs/ocfs2/xattr.c:1483 [inline] ocfs2_xa_set+0x15e3/0x2ec0 fs/ocfs2/xattr.c:2294 ocfs2_xattr_block_set+0x3e0/0x33c0 fs/ocfs2/xattr.c:3016 __ocfs2_xattr_set_handle+0x6b3/0xf50 fs/ocfs2/xattr.c:3418 ocfs2_xattr_set+0xf3f/0x13e0 fs/ocfs2/xattr.c:3681 __vfs_setxattr+0x43c/0x480 fs/xattr.c:218 ... Fix by adding the standard is_handle_aborted() guard at the top of jbd2_journal_dirty_metadata() and returning -EROFS, matching the pattern used by every other entry point in this file. ocfs2_journal_dirty() already handles a non-zero return from jbd2_journal_dirty_metadata() correctly. Reported-by: syzbot+98f651460e558a21baae@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=98f651460e558a21baae Tested-by: syzbot+98f651460e558a21baae@syzkaller.appspotmail.com Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com> Reviewed-by: Zhang Yi <yi.zhang@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://patch.msgid.link/20260507050605.50081-1-kartikey406@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-06-03configfs_lookup(): don't leave ->s_dentry dangling on failureAl Viro
Normally ->s_dentry is cleared when dentry it's pointing to becomes negative (on eviction, realistically). However, that only happens if dentry gets to be positive in the first place; in case of inode allocation failure dentry never becomes positive, so ->d_iput() is not called at all. We do part of what normally would've been done by configfs_d_iput() (dropping the reference to configfs_dirent) manually, but we do not clear ->s_dentry there. Sloppy as it is, it does not matter in case of configfs_create_{dir,link}() - there configfs_dirent does not survive dropping the sole reference to it. However, for configfs_lookup() it *does* survive, with a dangling pointer to soon to be freed dentry sitting it its ->s_dentry. Subsequent getdents(2) in that directory will end up dereferencing that pointer in order to pick the inode number. Use after free... This is the minimal fix; the right approach is to set the linkage between dentry and configfs_dirent only after we know that we have an inode, but that takes more surgery and the bug had been there since 2006, so... Fixes: 3d0f89bb1694 ("configfs: Add permission and ownership to configfs objects") # 2.6.16-rc3 Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Breno Leitao <leitao@debian.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2026-06-03fs: retire sget()Christian Brauner
sget() and sget_fc() have lived side by side as near-duplicate find-or-create-and-publish helpers for the legacy and fs_context mount APIs. The three remaining in-tree callers (CIFS plus the ext4 extents and mballoc KUnit tests) have all been moved to sget_fc(). Nothing calls sget() anymore. Delete sget() from fs/super.c and the prototype in <linux/fs.h>. Update the two comments that referred to "sget()" or "sget{_fc}()" to just say "sget_fc()". This removes ~60 lines of code that only existed to be kept in lockstep with sget_fc() on every superblock publish-path change. Link: https://patch.msgid.link/20260529-work-sget-v2-4-57bbe08604e4@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-03smb: client: convert cifs_smb3_do_mount() to sget_fc()Christian Brauner
The CIFS mount path already runs through fs_context: smb3_get_tree() calls smb3_get_tree_common() with a struct fs_context * in hand. But the fc is dropped on the way to sget(). Plumb it through to sget_fc() so the legacy sget() interface can go. cifs_smb3_do_mount() now takes (struct fs_context *, struct smb3_fs_context *). The old (fs_type, flags) pair is reconstructed from fc->fs_type and fc->sb_flags. The flags argument was always passed as 0 by the sole caller anyway. The cifs_dbg diagnostic now prints fc->sb_flags directly. cifs_match_super() and cifs_set_super() were the two void-data callbacks for sget(). The match callback now takes (struct super_block *, struct fs_context *) and reads struct cifs_mnt_data out of fc->sget_key. The set callback is gone entirely: sget_fc() pre-populates sb->s_fs_info from fc->s_fs_info before invoking set() so set_anon_super_fc() (which just allocates an anon bdev) is sufficient. Before sget_fc() we stash cifs_sb in fc->s_fs_info, the per-mount data in fc->sget_key and force fc->sb_flags to SB_NODIRATIME | SB_NOATIME to reproduce the previous hard-coded behaviour (alloc_super() reads fc->sb_flags). The original sb_flags is saved and restored around the call so the rest of the mount path sees the same fc semantics as before. mnt_data.flags keeps its historical value of 0 so the CIFS_MS_MASK comparison in compare_mount_options() returns the same (always-equal) result. No functional change. With this in place sget() has no remaining CIFS caller. Link: https://patch.msgid.link/20260529-work-sget-v2-3-57bbe08604e4@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-03ext4: convert mballoc KUnit test to sget_fc()Christian Brauner
Same treatment as the extents KUnit test. The mballoc test uses sget() as a thin "give me an initialized superblock" wrapper for a fake file_system_type. Move it onto sget_fc() so sget() can go away. Add a no-op mbt_init_fs_context() so fs_context_for_mount() has something to call on the fake fs_type. mbt_set() now takes a struct fs_context * (still a no-op). mbt_ext4_alloc_super_block() allocates the fc, hands it to sget_fc() and drops the fc reference once the sb is published. No functional change. Link: https://patch.msgid.link/20260529-work-sget-v2-2-57bbe08604e4@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-03ext4: convert extents KUnit test to sget_fc()Christian Brauner
The extents KUnit test uses sget() to get an initialized superblock for its fake file_system_type. sget() predates fs_context and we want to retire it. Switch this caller over to sget_fc(). Add a no-op ext_init_fs_context() so fs_context_for_mount() has something to call on the fake fs_type. ext_set() now takes a struct fs_context * (still a no-op). extents_kunit_init() allocates the fc, hands it to sget_fc() and drops the fc reference once the sb is published. sget_fc() does not retain a pointer to it. No functional change for the test. Link: https://patch.msgid.link/20260529-work-sget-v2-1-57bbe08604e4@kernel.org Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-06-02userfaultfd: ensure mremap_userfaultfd_fail() releases mmap_changingMike Rapoport (Microsoft)
Sashiko says: mremap_userfaultfd_prep() increments ctx->mmap_changing to stall concurrent operations, but mremap_userfaultfd_fail() does not decrement it before dropping the context reference. If an mremap operation fails, ctx->mmap_changing remains elevated. This will causes subsequent userfaultfd operations like a UFFDIO_COPY to fail with -EAGAIN. Decrement ctx->mmap_changing in mremap_userfaultfd_fail(). Link: https://sashiko.dev/#/patchset/20260430113512.115938-1-rppt@kernel.org Link: https://lore.kernel.org/20260513081416.495963-1-rppt@kernel.org Fixes: df2cc96e7701 ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-06-02tick/sched: Consolidate idle time fetching APIsFrederic Weisbecker
Fetching the idle cputime is available through a variety of accessors all over the place depending on the different accounting flavours and needs: - idle vtime generic accounting can be accessed by kcpustat_field(), kcpustat_cpu_fetch(), get_idle/iowait_time() and get_cpu_idle/iowait_time_us() - dynticks-idle accounting can only be accessed by get_idle/iowait_time() or get_cpu_idle/iowait_time_us() - CONFIG_NO_HZ_COMMON=n idle accounting can be accessed by kcpustat_field() kcpustat_cpu_fetch(), or get_idle/iowait_time() but not by get_cpu_idle/iowait_time_us() Moreover get_idle/iowait_time() relies on get_cpu_idle/iowait_time_us() with a non-sensical conversion to microseconds and back to nanoseconds on the way. Start consolidating the APIs with removing get_idle/iowait_time() and make kcpustat_field() and kcpustat_cpu_fetch() work for all cases. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com> Link: https://patch.msgid.link/20260508131647.43868-13-frederic@kernel.org
2026-06-02ntfs3: fix out-of-bounds read in ntfs_dir_emit() and hdr_find_e()Alessandro Schino
The bounds check in ntfs_dir_emit() compares fname->name_len (a character count) against e->size (a byte count) without accounting for the 2-byte-per-character UTF-16LE encoding or the ATTR_FILE_NAME header size: if (fname->name_len + sizeof(struct NTFS_DE) > le16_to_cpu(e->size)) This computes: name_len + 16 > e_size The correct check must account for the ATTR_FILE_NAME header (66 bytes before the name) and the UTF-16LE character size (2 bytes each): sizeof(NTFS_DE) + offsetof(ATTR_FILE_NAME, name) + name_len * sizeof(short) > e_size Which computes: 16 + 66 + name_len * 2 > e_size The correct calculation already exists as fname_full_size() in ntfs.h and is used in cmp_fnames(), namei.c, and fslog.c, but was not used in the readdir path. A crafted NTFS image with an index entry containing a small e->size but large fname->name_len bypasses the current check, causing ntfs_utf16_to_nls() to read past the entry boundary. Additionally, add a key_size validation in hdr_find_e() to ensure the declared key_size does not exceed the available entry data, preventing comparison functions from reading past entry boundaries on the lookup path. Signed-off-by: Alessandro Schino <7991aleschino@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: fix mount failure on 64K page-size kernelsJamie Nguyen
On 64K page-size kernels, mounting NTFS volumes smaller than ~650 MB fails with EINVAL. The issue is in log_replay(): the initial log page size probe uses PAGE_SIZE (65536) instead of DefaultLogPageSize (4096) when PAGE_SIZE exceeds DefaultLogPageSize * 2. This makes norm_file_page() require the $LogFile to be at least 50 * 65536 = 3.2 MB, but mkfs.ntfs creates a $LogFile of only ~1.5 MB for a typical 300 MB volume. norm_file_page() returns 0 and the mount is rejected with EINVAL. On 4K kernels the #if guard evaluates to true, so use_default=true is passed and DefaultLogPageSize (4096) is used, requiring only ~200 KB. This path works fine. Fix this by always passing use_default=true, which forces the initial probe to use DefaultLogPageSize regardless of the kernel's PAGE_SIZE. This is safe because, after reading the on-disk restart area, log_replay() already re-adjusts log->page_size to match the volume's actual sys_page_size. Also fix read_log_page() to pass log->page_size instead of PAGE_SIZE to ntfs_fix_post_read(), matching the actual buffer size. Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Tested-by: Matthew R. Ochs <mochs@nvidia.com> Signed-off-by: Jamie Nguyen <jamien@nvidia.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02ntfs3: avoid another -Wmaybe-uninitialized warningArnd Bergmann
The ntfs3 specific -Wmaybe-uninitialized flag found one more false-postive, this time with gcc-10 on s390: fs/ntfs3/frecord.c: In function 'ni_expand_list': fs/ntfs3/frecord.c:1370:16: error: 'ins_attr' may be used uninitialized in this function [-Werror=maybe-uninitialized] Add an explicit NULL pointer check before using the pointer, and initialize it to NULL. Fixes: 48d9b57b169f ("fs/ntfs3: add a subset of W=1 warnings for stricter checks") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02ntfs3: Allocate iomap inline_data using alloc_pageMihai Brodschi
This fixes a BUG reported in iomap_write_end_inline: iomap_inline_data_valid checks that the inline_data fits within a page. If the inline_data is allocated with kmemdup there's no guarantee that it's page-aligned, so the check sometimes fails. Allocate it with alloc_page to ensure it's page-aligned. Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221446 Fixes: 099ef9ab9203 ("fs/ntfs3: implement iomap-based file operations") Signed-off-by: Mihai Brodschi <m.brodschi@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: format code, deal with commentsKonstantin Komarov
format code according to .clang-format, add useful comments and remove non-useful comments. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: reject SEEK_DATA and SEEK_HOLE past EOF earlyKonstantin Komarov
Handle non-data/hole seeks through generic_file_llseek_size() and return -ENXIO immediately when SEEK_DATA or SEEK_HOLE is requested at or past EOF. Handle compressed files in such cases properly as well. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: fold file size handling into ntfs_set_size()Konstantin Komarov
Remove the separate ntfs_extend() and ntfs_truncate() helpers and route file size changes through ntfs_set_size(). This consolidates ntfs3 size updates in one place and lets the write, fallocate, and setattr paths share the same logic for updating i_size, valid data length, and preallocated extents. This patch fixes a few issues found during internal tests. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: force waiting for direct I/O completionKonstantin Komarov
It makes ntfs3 wait for direct I/O completion before returning to the caller, instead of allowing the write path to complete asynchronously. The issue was discovered during internal tests. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: fold resident writeback into writepages loopKonstantin Komarov
Remove the separate ntfs_resident_writepage() helper and handle resident writeback directly from ntfs_writepages(). This simplifies the resident writeback path and keeps the folio handling local to ntfs_writepages(). Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: handle delayed allocation overlap in run lookupKonstantin Komarov
Introduce run_lookup_entry_da() to look up data runs while taking delayed allocation into account. ntfs3 may have both committed extents and delayed allocation extents for the same VCN range. The new helper checks delayed allocation first and falls back to the real run, then corrects the returned range when a real run overlaps with a delayed allocation run. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: zero stale pagecache beyond valid data lengthKonstantin Komarov
Zero cached folios beyond the valid data length when closing a writable mapping. This keeps cached data beyond initialized file contents zeroed and prevents stale pagecache exposure after mmap-based writes. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: add fileattr supportKonstantin Komarov
Implement fileattr_get() and fileattr_set() to fix a problem found during the internal testing. This allows ntfs3 to expose and modify inode flags through the generic file attribute interface used by FS_IOC_GETFLAGS and FS_IOC_SETFLAGS. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: call _ntfs_bad_inode() when failing to renameHelen Koike
It is safe to call _ntfs_bad_inode on live inodes since: commit 519b078998ce ("fs/ntfs3: Exclude call make_bad_inode for live nodes.") The WARN_ON was added when it wasn't safe by: commit d99208b91933 ("fs/ntfs3: cancle set bad inode after removing name fails") Replace the WARN_ON with a call to _ntfs_bad_inode() to prevent further operations on the inconsistent inode. Reported-by: syzbot+4d8e30dbafb5c1260479@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4d8e30dbafb5c1260479 Fixes: 519b078998ce ("fs/ntfs3: Exclude call make_bad_inode for live nodes.") Signed-off-by: Helen Koike <koike@igalia.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: fix wrong LCN in run_remove_range() when splitting a runZhan Xusheng
When run_remove_range() removes a middle portion of a non-sparse run, it splits the run into head and tail parts. The tail is inserted via run_add_entry() but uses the original r->lcn as its starting LCN instead of advancing it by the split offset. For example, removing VCN range [10, 20) from a run {vcn=0, lcn=100, len=30} should produce: {vcn=0, lcn=100, len=10} (head) {vcn=20, lcn=120, len=10} (tail, lcn advanced by 20) But the current code produces: {vcn=0, lcn=100, len=10} {vcn=20, lcn=100, len=10} (wrong: points to same physical clusters) This creates overlapping physical mappings in the in-memory run tree, which can corrupt cluster allocation decisions and lead to data corruption. The correct pattern is already used in run_insert_range(): CLST lcn2 = r->lcn == SPARSE_LCN ? SPARSE_LCN : (r->lcn + len1); Apply the same logic in run_remove_range(). Fixes: 10d7c95af043 ("fs/ntfs3: add delayed-allocation (delalloc) support") Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: validate Dirty Page Table capacity in log_replay copy_lcnsYunpeng Tian
In the analysis pass of $LogFile journal replay, log_replay() copies LCNs from each action log record into an existing Dirty Page Table (DPT) entry without bounding the destination index. A crafted NTFS image with DPT entry lcns_follow=1 and an action log record with lcns_follow=2 produces a kernel slab out-of-bounds write at mount time: BUG: KASAN: slab-out-of-bounds in log_replay+0x654c/0xdb60 Write of size 8 at addr ffff8880095e1040 by task mount Two attacker-controlled fields can drive j+i past the allocated page_lcns[] array: 1. dp->lcns_follow (capacity) can be smaller than lrh->lcns_follow. 2. lrh->target_vcn may be smaller than dp->vcn, making the u64 subtraction wrap to a huge size_t. Validate target VCN delta and per-record LCN count against the DPT entry capacity, bail via the existing out: cleanup label with -EINVAL. This mirrors the bounds-check pattern added in commit b2bc7c44ed17 ("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot") and commit 0ca0485e4b2e ("fs/ntfs3: validate rec->used in journal-replay file record check"). Fixes: b46acd6a6a62 ("fs/ntfs3: Add NTFS journal") Reported-by: Yunpeng Tian <shionthanatos@gmail.com> Reported-by: Mingda Zhang <npczmd@qq.com> Reported-by: Gongming Wang <gmwgg05@gmail.com> Reported-by: Peiyuan Xu <paulbucket12@gmail.com> Reported-by: Qinrun Dai <jupmouse@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Yunpeng Tian <shionthanatos@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: fix syncing wrong inode on DIRSYNC cross-directory renameZhan Xusheng
In ntfs3_rename(), when IS_DIRSYNC(new_dir) is true, the code syncs the renamed file inode instead of the target directory new_dir: if (IS_DIRSYNC(new_dir)) ntfs_sync_inode(inode); /* should be new_dir */ DIRSYNC requires that directory metadata changes are written to disk synchronously. Since new_dir was modified (a new directory entry was added), it is new_dir that must be synced to satisfy the guarantee, not the renamed file itself. This bug has existed since the initial ntfs3 implementation and was carried through the refactoring in commit 78ab59fee07f ("fs/ntfs3: Rework file operations"). Fix by syncing new_dir instead of inode. Fixes: 4342306f0f0d ("fs/ntfs3: Add file operations and implementation") Cc: stable@vger.kernel.org Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: validate index entry key boundsZhengYuan Huang
[BUG] A malformed NTFS directory index entry can advertise a key_size larger than the bytes actually present in its NTFS_DE payload. Directory lookup then passes that malformed key to cmp_fnames(), which can read past the end of the kmalloc'ed index buffer. BUG: KASAN: slab-out-of-bounds in fname_full_size fs/ntfs3/ntfs.h:590 [inline] BUG: KASAN: slab-out-of-bounds in cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46 Read of size 1 at addr ffff88801c313018 by task syz.6.3365/9279 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xd1/0x650 mm/kasan/report.c:482 kasan_report+0xfb/0x140 mm/kasan/report.c:595 __asan_report_load1_noabort+0x14/0x30 mm/kasan/report_generic.c:378 fname_full_size fs/ntfs3/ntfs.h:590 [inline] cmp_fnames+0x1ea/0x230 fs/ntfs3/index.c:46 hdr_find_e.isra.0+0x3ed/0x670 fs/ntfs3/index.c:762 indx_find+0x4b5/0x900 fs/ntfs3/index.c:1186 dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254 ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85 __lookup_slow+0x241/0x450 fs/namei.c:1816 lookup_slow fs/namei.c:1833 [inline] walk_component+0x31c/0x570 fs/namei.c:2151 link_path_walk+0x592/0xd60 fs/namei.c:2519 path_lookupat+0x138/0x660 fs/namei.c:2675 filename_lookup+0x1f3/0x560 fs/namei.c:2705 filename_setxattr+0xad/0x1c0 fs/xattr.c:660 path_setxattrat+0x1d8/0x280 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750 ... Allocated by task 9279: kasan_save_stack+0x39/0x70 mm/kasan/common.c:56 kasan_save_track+0x14/0x40 mm/kasan/common.c:77 kasan_save_alloc_info+0x37/0x60 mm/kasan/generic.c:573 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xc3/0xd0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5650 [inline] __kmalloc_noprof+0x2bd/0x900 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] indx_read+0x41d/0xad0 fs/ntfs3/index.c:1059 indx_find+0x447/0x900 fs/ntfs3/index.c:1179 dir_search_u+0x2c0/0x460 fs/ntfs3/dir.c:254 ntfs_lookup+0x1cc/0x2a0 fs/ntfs3/namei.c:85 __lookup_slow+0x241/0x450 fs/namei.c:1816 lookup_slow fs/namei.c:1833 [inline] walk_component+0x31c/0x570 fs/namei.c:2151 link_path_walk+0x592/0xd60 fs/namei.c:2519 path_lookupat+0x138/0x660 fs/namei.c:2675 filename_lookup+0x1f3/0x560 fs/namei.c:2705 filename_setxattr+0xad/0x1c0 fs/xattr.c:660 path_setxattrat+0x1d8/0x280 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xd0/0x150 fs/xattr.c:750 ... [CAUSE] The index-header validators only validated INDEX_HDR-level geometry. They did not walk each NTFS_DE to verify entry alignment, subnode layout, or that key_size fit inside the entry payload. They also allowed a last sentinel entry to carry a non-zero key_size. [FIX] Walk every NTFS_DE in ntfs3's index-header validators and reject entries with invalid layout, mismatched subnode state, oversized key_size, or non-zero sentinel keys before lookup or log replay can consume them. Signed-off-by: ZhengYuan Huang <gality369@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: preserve non-DOS attribute bits in system.dos_attribZhengYuan Huang
[BUG] A corrupted ntfs3 image can hit a NULL function pointer call in generic_perform_write() after toggling system.ntfs_attrib and then overwriting system.dos_attrib on the same file. BUG: kernel NULL pointer dereference, address: 0000000000000000 \#PF: supervisor instruction fetch in kernel mode \#PF: error_code(0x0010) - not-present page PGD bed5067 P4D bed5067 PUD 0 Oops: Oops: 0010 [#1] SMP KASAN NOPTI RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0018:ffff88801025f988 EFLAGS: 00010246 Call Trace: generic_perform_write+0x409/0x8c0 mm/filemap.c:4255 __generic_file_write_iter+0x1bb/0x200 mm/filemap.c:4372 ntfs_file_write_iter+0xcd9/0x1c20 fs/ntfs3/file.c:1253 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x63b/0xf70 fs/read_write.c:686 ksys_write+0x133/0x250 fs/read_write.c:738 __do_sys_write fs/read_write.c:749 [inline] __se_sys_write fs/read_write.c:746 [inline] __x64_sys_write+0x77/0xc0 fs/read_write.c:746 ... [CAUSE] system.ntfs_attrib updates ATTR_DATA flags via ni_new_attr_flags() and switches i_mapping->a_ops to ntfs_aops_cmpr when FILE_ATTRIBUTE_COMPRESSED is set. system.dos_attrib then overwrites ni->std_fa from a one-byte DOS attribute value, clearing the compression bit without updating ATTR_DATA or the mapping operations. Old buffered writes use is_compressed(ni) to choose __generic_file_write_iter(). That leaves generic_perform_write() calling a NULL write_begin callback from ntfs_aops_cmpr. [FIX] Treat system.dos_attrib as a low-byte DOS attribute update and preserve the existing non-DOS attribute bits in ni->std_fa. This keeps compressed and sparse state consistent with ATTR_DATA and the mapping operations while keeping the existing DOS attribute semantics intact. Signed-off-by: ZhengYuan Huang <gality369@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: hold ni_lock across readdir metadata walkZhengYuan Huang
[BUG] KASAN reports a slab-use-after-free during getdents(2): BUG: KASAN: slab-use-after-free in ntfs_read_mft fs/ntfs3/inode.c:79 [inline] BUG: KASAN: slab-use-after-free in ntfs_iget5+0x59b/0x3450 fs/ntfs3/inode.c:541 Read of size 2 at addr ffff88800b7a5a4e by task syz.0.1061/2354 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xd1/0x650 mm/kasan/report.c:482 kasan_report+0xfb/0x140 mm/kasan/report.c:595 __asan_report_load2_noabort+0x14/0x30 mm/kasan/report_generic.c:379 ntfs_read_mft fs/ntfs3/inode.c:79 [inline] ntfs_iget5+0x59b/0x3450 fs/ntfs3/inode.c:541 ntfs_dir_emit fs/ntfs3/dir.c:337 [inline] ntfs_read_hdr+0x714/0x930 fs/ntfs3/dir.c:385 ntfs_readdir+0xaad/0x1010 fs/ntfs3/dir.c:458 iterate_dir+0x276/0x9e0 fs/readdir.c:108 __do_sys_getdents fs/readdir.c:326 [inline] __se_sys_getdents fs/readdir.c:312 [inline] __x64_sys_getdents+0x143/0x290 fs/readdir.c:312 ... Allocated by task 2160: kasan_save_stack+0x39/0x70 mm/kasan/common.c:56 kasan_save_track+0x14/0x40 mm/kasan/common.c:77 kasan_save_alloc_info+0x37/0x60 mm/kasan/generic.c:573 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xc3/0xd0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5650 [inline] __kmalloc_noprof+0x2bd/0x900 mm/slub.c:5662 kmalloc_noprof include/linux/slab.h:961 [inline] mi_init+0x9d/0x110 fs/ntfs3/record.c:105 mi_format_new+0x6b/0x500 fs/ntfs3/record.c:422 ni_add_subrecord+0x129/0x540 fs/ntfs3/frecord.c:321 ntfs_look_free_mft+0x238/0xd90 fs/ntfs3/fsntfs.c:715 ni_create_attr_list+0x8e6/0x1690 fs/ntfs3/frecord.c:826 ni_ins_attr_ext+0x5ec/0x9d0 fs/ntfs3/frecord.c:924 ni_insert_attr+0x2bf/0x830 fs/ntfs3/frecord.c:1091 ni_insert_resident+0xec/0x3d0 fs/ntfs3/frecord.c:1475 ni_add_name+0x4b2/0x8a0 fs/ntfs3/frecord.c:2987 ni_rename+0xa6/0x160 fs/ntfs3/frecord.c:3026 ntfs_rename+0xa19/0xe00 fs/ntfs3/namei.c:332 vfs_rename+0xd42/0x1d50 fs/namei.c:5216 do_renameat2+0x715/0xb60 fs/namei.c:5364 __do_sys_rename fs/namei.c:5411 [inline] __se_sys_rename fs/namei.c:5409 [inline] __x64_sys_rename+0x83/0xb0 fs/namei.c:5409 x64_sys_call+0x8c4/0x26a0 arch/x86/include/generated/asm/syscalls_64.h:83 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x93/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 85: kasan_save_stack+0x39/0x70 mm/kasan/common.c:56 kasan_save_track+0x14/0x40 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x6f/0xa0 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2543 [inline] slab_free mm/slub.c:6642 [inline] kfree+0x2bf/0x6b0 mm/slub.c:6849 mi_clear fs/ntfs3/ntfs_fs.h:1107 [inline] mi_put+0x10e/0x1a0 fs/ntfs3/record.c:97 ni_write_inode+0x479/0x2a00 fs/ntfs3/frecord.c:3320 ntfs3_write_inode+0x51/0x70 fs/ntfs3/inode.c:1042 write_inode fs/fs-writeback.c:1564 [inline] __writeback_single_inode+0x8c9/0xc30 fs/fs-writeback.c:1784 writeback_sb_inodes+0x5e6/0xf60 fs/fs-writeback.c:2015 __writeback_inodes_wb+0x10c/0x2d0 fs/fs-writeback.c:2086 wb_writeback+0x63f/0x900 fs/fs-writeback.c:2197 wb_check_old_data_flush fs/fs-writeback.c:2301 [inline] wb_do_writeback fs/fs-writeback.c:2354 [inline] wb_workfn+0x8cc/0xd60 fs/fs-writeback.c:2382 process_one_work+0x8e0/0x1980 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x683/0xf80 kernel/workqueue.c:3427 kthread+0x3f0/0x850 kernel/kthread.c:463 ret_from_fork+0x50f/0x610 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The faulting address sits 590 bytes inside a freed kmalloc-1k object allocated by ni_add_subrecord() and freed from ni_write_inode() writeback. [CAUSE] ntfs_readdir() loads all subrecords once, but then drops ni_lock() before it starts walking the directory metadata through ntfs_read_hdr(). That leaves the current NTFS_DE pointer backed by parent-directory subrecord memory that concurrent writeback is still allowed to compact and free. The later ntfs_dir_emit() -> ntfs_iget5() call exposes the stale e->ref, but the lifetime bug starts earlier: readdir is still consuming parent-directory metadata after releasing the lock that protects it. [FIX] Keep ni_lock() held from the point where ntfs_readdir() starts consuming the directory metadata until the walk over root/index entries is finished. This closes the parent-directory lifetime hole directly and keeps the existing readdir d_type behaviour unchanged. Signed-off-by: ZhengYuan Huang <gality369@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02ntfs3: avoid -Wmaybe-uninitialized warningArnd Bergmann
This warning shows up with gcc-10 now: In file included from fs/ntfs3/index.c:15: fs/ntfs3/index.c: In function 'indx_add_allocate': fs/ntfs3/ntfs_fs.h:463:9: error: 'bmp_size' may be used uninitialized in this function [-Werror=maybe-uninitialized] 463 | return attr_set_size_ex(ni, type, name, name_len, run, new_size, | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 464 | new_valid, keep_prealloc, NULL, false); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/ntfs3/index.c:1498:6: note: 'bmp_size' was declared here 1498 | u64 bmp_size, bmp_size_v; | ^~~~~~~~ The warning does look correct, as the 'out2' label can be reached without initializing bmp_size and bmp_size_v. Initialize these at the same place as bmp. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02fs/ntfs3: add bounds check to run_get_highest_vcn()Konstantin Komarov
run_get_highest_vcn() parses a packed NTFS mapping-pairs buffer without any length bound, relying solely on a 0x00 terminator to stop. A crafted $LogFile UpdateMappingPairs record whose embedded attribute contains mapping-pairs runs without a terminator causes the function to read past the slab allocation, triggering a KASAN slab-out-of-bounds read on mount. The sibling function run_unpack() received an analogous bounds-check in commit b62567bca474 ("ntfs3: add buffer boundary checks to run_unpack()"), but run_get_highest_vcn() was missed. Take a run_buf_size parameter and reject any run header whose payload would extend past the buffer end, mirroring the pattern used by run_unpack(). The caller in fslog.c passes the remaining attribute bytes after the mapping-pairs offset. KASAN report (on mainline v7.1 merge window HEAD): BUG: KASAN: slab-out-of-bounds in run_get_highest_vcn+0x3c0/0x410 Read of size 1 at addr ffff88800e2d5400 by task mount/72 Call Trace: run_get_highest_vcn+0x3c0/0x410 do_action.isra.0+0x3ba8/0x7b50 log_replay+0x9ddd/0x10200 ntfs_loadlog_and_replay+0x4ad/0x610 ntfs_fill_super+0x214a/0x4540 Fixes: b62567bca474 ("ntfs3: add buffer boundary checks to run_unpack()") Signed-off-by: Jaeyeong Lee <lee@jaeyeong.cc> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2026-06-02mount: honour SB_NOUSER in the new mount APIAl Viro
One should *not* be allowed to mount one of those, new API or not. Reported-by: Denis Arefev <arefev@swemel.ru> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Link: https://patch.msgid.link/20260602020444.GP2636677@ZenIV Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>