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2026-09-02btrfs: zstd: fix lost wakeup when waiting for a workspaceFAN YE
A writer can sleep forever in zstd_get_workspace() even though a workspace is free. When zstd_alloc_workspace() fails, the task is queued on zwsm->wait and schedules unconditionally, never re-testing the pool. zstd_put_workspace() publishes the workspace and then calls cond_wake_up(), which only wakes when a sleeper is already visible, so a workspace returned between the failed allocation and prepare_to_wait() wakes nobody. The window is wide: zstd_alloc_workspace() goes through kvmalloc() and may enter reclaim. Only a max level workspace triggers the wakeup and one is deliberately kept allocated as the fallback every waiter waits for, so once its wakeup is lost the writer stays in TASK_UNINTERRUPTIBLE until some other task happens to return one. Re-check the pool after prepare_to_wait() has published the waiter, and use the workspace if one turned up. Fixes: 3f93aef535c8 ("btrfs: add zstd compression level support") Assisted-by: Claude:claude-opus-5 Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: FAN YE <fy15309206903@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: do not force reloc root creation during qgroup_account_snapshot()Qu Wenruo
[BUG] When running btrfs/252 with quota enabled through MKFS_OPTIONS="-O quota", it has a high chance to trigger the following kernel warning and flips the fs RO: BTRFS info (device dm-2): relocating block group 30408704 flags metadata|dup ------------[ cut here ]------------ WARNING: fs/btrfs/extent-tree.c:879 at lookup_inline_extent_backref+0x74b/0x960 [btrfs], CPU#4: btrfs/2173 CPU: 4 UID: 0 PID: 2173 Comm: btrfs Not tainted 7.2.0-rc6-custom+ #457 PREEMPT(full) 3adc6528fb66f7a55fe1095385818e742f200aab Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:lookup_inline_extent_backref+0x74b/0x960 [btrfs] Call Trace: <TASK> insert_inline_extent_backref+0x7c/0x160 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] __btrfs_inc_extent_ref+0xa9/0x270 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] __btrfs_run_delayed_refs+0x4af/0x11c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_run_delayed_refs+0x9d/0xf0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] create_pending_snapshot+0x39d/0xf00 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] create_pending_snapshots+0x9b/0xc0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_commit_transaction+0x280/0xeb0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] prepare_to_relocate+0x147/0x200 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] relocate_block_group+0x6b/0x5e0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_relocate_block_group+0x92c/0x2380 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_relocate_chunk+0x3f/0x1a0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_balance+0xa2c/0x19c0 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] btrfs_ioctl+0x2839/0x2d30 [btrfs 32f09462c54d9c922fca74a3e4866f4aa7737b72] __x64_sys_ioctl+0x416/0x9a0 do_syscall_64+0xe1/0x790 entry_SYSCALL_64_after_hwframe+0x4b/0x53 </TASK> ---[ end trace 0000000000000000 ]--- BTRFS info (device dm-2): leaf 4593991680 gen 233 total ptrs 175 free space 5953 owner 2 BTRFS info (device dm-2): refs 3 lock_owner 2173 current 2173 item 0 key (166772736 METADATA_ITEM 1) itemoff 16250 itemsize 33 extent refs 1 gen 222 flags 2 ref#0: tree block backref root 266 [ Skip the tree dump ] item 174 key (263225344 METADATA_ITEM 0) itemoff 10328 itemsize 33 extent refs 1 gen 162 flags 258 ref#0: tree block backref root 267 BTRFS error (device dm-2): extent item not found for insert, bytenr 179847168 num_bytes 16384 parent 4594335744 root_objectid 273 owner 0 offset 0 BTRFS error (device dm-2): failed to run delayed ref for logical 179847168 num_bytes 16384 type 182 action 1 ref_mod 1: -117 [CAUSE] The above error is showing that there is a tree reference to a metadata extent that is no longer there. With "ref_verify" mount option (requires CONFIG_BTRFS_DEBUG), there is some extra debug output: BTRFS error (device dm-2): dumping block entry [180961280 16384], num_refs 0, metadata 1, from disk 0 BTRFS error (device dm-2): root entry 256, num_refs 18446744073709551615 BTRFS error (device dm-2): root entry 273, num_refs 18446744073709551615 BTRFS error (device dm-2): Ref action 3, root 273, ref_root 273, parent 0, owner 0, offset 0, num_refs 1 btrfs_force_cow_block+0x129/0x7d0 [btrfs] btrfs_cow_block+0x10a/0x250 [btrfs] btrfs_search_slot+0x5eb/0xf40 [btrfs] btrfs_insert_empty_items+0x3a/0x70 [btrfs] insert_with_overflow+0x53/0x130 [btrfs] btrfs_insert_dir_item+0x125/0x290 [btrfs] btrfs_add_link+0xaa/0x410 [btrfs] btrfs_rename+0x5ea/0xcd0 [btrfs] btrfs_rename2+0x28/0x60 [btrfs] vfs_rename+0x5b2/0xe10 filename_renameat2+0x244/0x430 __x64_sys_rename+0x48/0x70 do_syscall_64+0xe1/0x790 entry_SYSCALL_64_after_hwframe+0x4b/0x53 BTRFS error (device dm-2): Ref action 2, root 273, ref_root 273, parent 0, owner 0, offset 0, num_refs 18446744073709551615 btrfs_force_cow_block+0x327/0x7d0 [btrfs] btrfs_cow_block+0x10a/0x250 [btrfs] btrfs_search_slot+0x5eb/0xf40 [btrfs] btrfs_lookup_file_extent+0x4d/0x70 [btrfs] btrfs_drop_extents+0x151/0xf00 [btrfs] insert_reserved_file_extent+0xfe/0x3e0 [btrfs] btrfs_finish_one_ordered+0x549/0xc40 [btrfs] btrfs_work_helper+0xde/0x350 [btrfs] process_one_work+0x198/0x380 worker_thread+0x1c8/0x330 kthread+0xee/0x120 ret_from_fork+0x28f/0x310 ret_from_fork_asm+0x11/0x20 BTRFS error (device dm-2): Ref action 1, root 273, ref_root 0, parent 4594335744, owner 0, offset 0, num_refs 1 __btrfs_mod_ref+0x1c5/0x2d0 [btrfs] btrfs_copy_root+0x262/0x390 [btrfs] create_reloc_root+0xb9/0x370 [btrfs] btrfs_init_reloc_root+0xb0/0x1b0 [btrfs] record_root_in_trans+0xa6/0xd0 [btrfs] create_pending_snapshot+0x383/0xf00 [btrfs] create_pending_snapshots+0x9b/0xc0 [btrfs] btrfs_commit_transaction+0x280/0xeb0 [btrfs] prepare_to_relocate+0x147/0x200 [btrfs] relocate_block_group+0x6b/0x5e0 [btrfs] btrfs_relocate_block_group+0x92c/0x2380 [btrfs] btrfs_relocate_chunk+0x3f/0x1a0 [btrfs] btrfs_balance+0xa2c/0x19c0 [btrfs] btrfs_ioctl+0x2839/0x2d30 [btrfs] __x64_sys_ioctl+0x416/0x9a0 do_syscall_64+0xe1/0x790 The above shows the direct cause, Ref action 3 is the oldest operation, which shows the tree block is created by COW. Then ref action 2 shows it's COWed away, by a metadata update, meaning the tree block is already released, should not be referred any more. Then the final one, is trying to create a reloc tree for subvolume 273, and that reloc root creation is referring to the already dropped tree block. The root cause is that, during qgroup_account_snapshot(), we are calling record_root_in_trans() with "force = true". So if the root has no reloc root, we will create one, but at that timing it's already too late. Normally reloc root should be created before the commit and current roots diverge, to avoid the same problem we are hitting. But during relocation initialization, we are committing the current running transaction, with a new reloc_control attached halfway. And if qgroup is enabled, the record_root_in_trans() with "force = true" calls will force reloc root creation even if we do not and should not create reloc root at that timing. [FIX] Do not force reloc root creation during record_root_in_trans() with "force = true" cases, which is only called by qgroup_account_snapshot(). If we're really under relocation, the reloc root should be created way early, before the commit and current root diverge. If the root has no reloc tree yet, it means we're still initializing the reloc, and do not need a reloc root. So skipping the reloc tree creation in qgroup_account_snapshot() should be safe. Link: https://bugzilla.suse.com/show_bug.cgi?id=1275740 Fixes: 4d31778aa2fa ("btrfs: qgroup: Fix root item corruption when multiple same source snapshots are created with quota enabled") Assisted-by: LLM (initial analysis, but incorrect conclusion with too many burnt tokens) Tested-by: Disha Goel <disgoel@linux.ibm.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: send: fix lost error return value in will_overwrite_ref()Avi Weiss
The direct-return refactoring in commit b3047a42f55d ("btrfs: send: directly return from will_overwrite_ref() and simplify it") changed will_overwrite_ref() to return directly instead of going through the common out label. That resulted in a negative return value from is_inode_existent() to start being converted to 0, making lookup errors unable to be distinguished from the inode not existing. process_recorded_refs() expects negative errors from will_overwrite_ref() and aborts processing when it receives one. Return the value from is_inode_existent() to restore the previous error propagation behavior as it was before the refactor. Fixes: b3047a42f55d ("btrfs: send: directly return from will_overwrite_ref() and simplify it") Signed-off-by: Avi Weiss <thnkslprpt@gmail.com> Reviewed-by: Filipe Manana <fdmanana@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>
2026-09-02btrfs: abort transaction before releasing tree_log_mutex on commit failureLeo Martins
When transaction metadata writeout fails in btrfs_commit_transaction(), the current code only logs the error, drops tree_log_mutex and then goes through cleanup_transaction(), which aborts the transaction and records the fs error. That is too late for the tree log side. A log sync can already be waiting on tree_log_mutex, because the committing transaction is moved to TRANS_STATE_UNBLOCKED while that mutex is held, which lets fsyncs join the next transaction and queue up in btrfs_sync_log(). Once the failed commit drops tree_log_mutex, such a log sync acquires it, sees BTRFS_FS_ERROR() still clear, and writes super_for_commit. That superblock holds the roots prepared for the transaction that has just failed to write out its metadata, so it can point at tree blocks that never reached the disk, and the next mount fails with a parent transid mismatch. Commit 165ea85f1483 ("btrfs: do not write supers if we have an fs error") fixed this class of problem by making btrfs_sync_log() check for an fs error right after taking tree_log_mutex. That check only works if the commit path publishes the fs error before it releases the same mutex, and commit 68d4ece9c30e ("btrfs: don't call btrfs_handle_fs_error() in btrfs_commit_transaction()") removed the only thing that did so. Restore the ordering by aborting the transaction while tree_log_mutex is still held. We have a transaction handle here, so this does not need to bring back the btrfs_handle_fs_error() call: __btrfs_abort_transaction() records the fs error itself, which is all btrfs_sync_log() looks at, and the error message put in its place is kept. This is what commit 3810ab40afa5 ("btrfs: abort transaction on error in write_all_supers()") already does for the next call in this function. This is reproducible on an unmodified kernel by failing the first couple of bios of a transaction commit with fail_make_request while a concurrent fsync workload keeps log syncs queued on tree_log_mutex. Fixes: 68d4ece9c30e ("btrfs: don't call btrfs_handle_fs_error() in btrfs_commit_transaction()") CC: stable@vger.kernel.org # 7.0+ Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: jlayton@meta.com <jlayton@meta.com> Signed-off-by: Leo Martins <loemra.dev@gmail.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: zoned: propagate do_zone_finish() error in btrfs_zone_finish_endio()Johannes Thumshirn
btrfs_zone_finish_endio() ignored the return value of do_zone_finish() and always returned 0, silently dropping a failed zone finish. Instead propagate any error from do_zone_finish() as the caller btrfs_finish_ordered_io() already handles it. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: zoned: finish active block group cleanup if call_zone_finish() failsJohannes Thumshirn
do_zone_finish() clears BLOCK_GROUP_FLAG_ZONE_IS_ACTIVE before finishing the zones. If call_zone_finish() then fails it returned early, leaving the now inactive block group on fs_info->zone_active_bgs, leaking its reference, the BTRFS_FS_NEED_ZONE_FINISH waiters are never woken, and as its alloc_offset equals the zone capacity btrfs_zone_finish_one_bg() keeps selecting it, spinning btrfs_zoned_activate_one_bg(). Fall through to the cleanup on failure too and return the error, but keep the block group read-only as its zones are left inconsistent. Fixes: d70cbdda75da ("btrfs: zoned: consolidate zone finish functions") Link: https://sashiko.dev/#/patchset/20260818100037.1366563-1-johannes.thumshirn%40wdc.com Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: send: reject extents for non-regular inodesZhengYuan Huang
[BUG] A corrupted subvolume tree can leave an EXTENT_DATA item attached to an inode whose mode is not S_IFREG or S_IFLNK. During send, such an item can be treated as file data and crash through a NULL address_space operation: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page Call Trace: <TASK> read_pages+0x80b/0xb30 mm/readahead.c:173 page_cache_ra_unbounded+0x40d/0x890 mm/readahead.c:302 do_page_cache_ra mm/readahead.c:332 [inline] page_cache_ra_order+0xa16/0xcd0 mm/readahead.c:535 page_cache_sync_ra+0x5ce/0x9d0 mm/readahead.c:626 page_cache_sync_readahead include/linux/pagemap.h:1379 [inline] put_file_data fs/btrfs/send.c:5224 [inline] send_write fs/btrfs/send.c:5291 [inline] send_extent_data+0x16b2/0x29b0 fs/btrfs/send.c:5715 send_write_or_clone fs/btrfs/send.c:6135 [inline] process_extent+0x5d4/0x17b0 fs/btrfs/send.c:6504 changed_extent fs/btrfs/send.c:7079 [inline] changed_cb+0x22f9/0x3cd0 fs/btrfs/send.c:7245 full_send_tree fs/btrfs/send.c:7318 [inline] send_subvol fs/btrfs/send.c:7910 [inline] btrfs_ioctl_send+0x46a9/0x57f0 fs/btrfs/send.c:8248 ... [CAUSE] process_extent() skips extent items for symlinks but assumes every other inode with an extent item is a regular file. For a corrupted non-regular inode, btrfs_iget() does not install the regular file address_space operations. The readahead fallback can then call a NULL read_folio callback before the existing validation in btrfs_get_extent() can run. [FIX] Reject extent items for inode types other than regular files and symlinks at the common send extent-processing boundary. Symlink handling is left unchanged because send emits symlink data from read_symlink(). This covers full, incremental and new-generation sends without adding a check to the regular I/O path. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: ZhengYuan Huang <gality369@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: return proper negative error code for update_raid_extent_item()Qu Wenruo
The function btrfs_abort_transaction() only accepts negative error code, and have the macro VERIFY_NEGATIVE_ERROR() to verify that error code. But inside update_raid_extent_item(), if there is such key found, we return 1, breaking the negative error code scheme. Furthermore if we hit some real error during the tree search, e.g. -EIO, then the error code is always over-written to -EINVAL. Fix both problems by following other call sites by overwriting @ret to -ENOENT if the btrfs_search_slot() failed to locate the key. This is very unlikely to hit, as we only enter update_raid_extent_item() if there is a conflicting key already in the raid stripe tree. This was reported by Sashiko when reviewing another patch. Link: https://sashiko.dev/#/patchset/20260817021512.3010812-1-shuangpeng.kernel%40gmail.com Fixes: 8c4cba2adbb0 ("btrfs: update stripe extents for existing logical addresses") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: fix the possible bioc_list memory leak during errorQu Wenruo
There are two possible ways to leak bioc memory on btrfs_ordered_extent::bioc_list: - An error occurred for btrfs_insert_one_raid_extent() Then the function btrfs_insert_raid_extent() immediately return without freeing any bioc in the bioc_list. - An ordered extent hit an IO error In that case the ordered extent will have BTRFS_ORDERED_IOERR set, and skip the call on btrfs_insert_raid_extent() completely. Fix the problem by: - Introduce a new helper, btrfs_cleanup_ordered_bioc_list() Which will remove all bioc from the bioc_list, and release the bioc. - Call the above helper for btrfs_insert_raid_extent() So that the cleanup helper is always called no matter what. - Call the above helper for btrfs_finish_one_ordered() This is called just before the final release on the ordered extent. This was reported by Sashiko when reviewing another patch. Link: https://sashiko.dev/#/patchset/20260817021512.3010812-1-shuangpeng.kernel%40gmail.com Fixes: 02c372e1f016 ("btrfs: add support for inserting raid stripe extents") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: fix transaction use-after-free in raid stripe insertionShuangpeng Bai
If allocation of a RAID stripe extent fails, btrfs_insert_one_raid_extent() aborts and ends the transaction before returning -ENOMEM. btrfs_finish_one_ordered(), the production caller through btrfs_insert_raid_extent(), still owns the transaction handle. It handles the error by aborting the transaction and then reaches the common exit path, which ends the transaction again. The premature end can free the handle and drop its transaction reference. Transaction cleanup can then free the transaction before the caller's second abort accesses the handle and transaction, resulting in use-after-free. Keep the abort at the failure site, but let the caller's common exit path end the transaction once, after it has finished using both objects. Fixes: 02c372e1f016 ("btrfs: add support for inserting raid stripe extents") Assisted-by: Codex:GPT-5 Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Shuangpeng Bai <shuangpeng.kernel@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: scrub: report the failing sector's address, not the stripe baseJames C. Owens
scrub_stripe_report_errors() iterates over the sectors of a stripe, but every message it emits passes stripe->logical, the address of the first sector of the 64KiB stripe, rather than the address of the sector being reported. The physical address is likewise computed once, before the loop, from stripe->logical. This matters because scrub_print_common_warning() uses that logical address for the backref walk which produces the "root %llu inode %llu offset %llu ... (path: ...)" part of the message. As the address is always the stripe base, the reported root/inode/offset/path can identify a different file from the one whose sector actually failed. A 64KiB stripe routinely spans several extents belonging to unrelated files. On the machine where this was found, the stripe at logical 0x17D9380000 holds four sectors of /usr/share/plasma/emoji/bg.dict, then a file inside a docker volume, then sectors referenced only by snapshots. Every error anywhere in that stripe is attributed to bg.dict. The effect is visible statistically: across ten months and four kernel series that machine logged 81 distinct flagged logical addresses, and every one of them is exactly 64KiB aligned. Since BTRFS_STRIPE_LEN is 64KiB and stripe->logical is stripe aligned by construction, real failures distributed across sectors could not produce that. Report the address of the sector actually being examined. Adding the sector offset to the physical address is valid because BTRFS_STRIPE_LEN is the unit contiguous on a single device for every profile, so a stripe never crosses a device boundary. Fixes: 0096580713ff ("btrfs: scrub: introduce error reporting functionality for scrub_stripe") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: James C. Owens <jamesowens@optonline.net> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02smb: client: reject short READ responses in CIFSSMBRead()Diego Oliva
CIFSSMBRead() reads DataLengthHigh, DataLength and DataOffset out of the READ_RSP returned by the server without first checking that a whole READ_RSP was actually received. The length of the response is recorded in rsp_iov.iov_len, but nothing constrains it to be at least read_rsp_size before those fields are dereferenced. A malicious or compromised SMB1 server can return a response shorter than the READ_RSP header, so that parsing the header itself reads past the end of the receive buffer. SMB1 is not negotiated by default; reaching this code requires an explicit vers=1.0 mount. Reject the response unless it is at least read_rsp_size bytes long. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Suggested-by: Paulo Alcantara <pc@manguebit.org> Cc: stable@vger.kernel.org # 6.19.x Assisted-by: Bynario AI Signed-off-by: Diego Oliva <diego@bynar.io> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Paulo Alcantara <pc@manguebit.org>
2026-09-02dlm: wait for outstanding SRCU callbacks to complete in exit pathsZqiang
The dlm_lowcomms_exit() and dlm_midcomms_exit() iterate over the srcu protected connection and node hash tables and hand each element to call_srcu() for deferred freeing (connection_release() and midcomms_node_release()). call_srcu() is asynchronous: the callbacks are invoked only after an SRCU grace period, which may happen after the exit function has already returned. These exit functions are reached from exit_dlm() on module unload. Once they return, module teardown continues and the module text may be unloaded while call_srcu() callbacks are still pending. When such a callback finally runs, it executes freed module code and touches the static SRCU domains that are being torn down, resulting in a use-after-free. Add an srcu_barrier() after the call_srcu() loop in each exit function to wait for all outstanding callbacks of the respective SRCU domain to complete before returning. In dlm_midcomms_exit() the barrier is issued before dlm_lowcomms_exit() so that node callbacks are drained prior to tearing down the lower layer. Signed-off-by: Zqiang <qiang.zhang@linux.dev> Acked-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2026-09-02dlm: fix variable key length lookupAlexander Aring
Before commit 6c648035cbe7 ("dlm: switch to use rhashtable for rsbs") the rsb hashtable was dynamic key length. Accidentally it was changed to switch to static key length which can end in different results. We fixing this back to the original behaviour by adding the necessary functionality to rhashtable to handle the objects and lookups as dynamic key lengths. Fixes: 6c648035cbe7 ("dlm: switch to use rhashtable for rsbs") Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2026-09-02dlm: fix NULL pointer dereference in dlm_dump_rsb_name()Danila Chernetsov
The function dlm_dump_rsb_name() is called from receive_rcom_lookup() when a debug dump is requested via a special RCOM_LOOKUP message with rc_id == 0xFFFFFFFF. The resource name passed to dlm_dump_rsb_name() comes from the received message. There is no guarantee that an RSB with this name exists in the local hash table. dlm_search_rsb_tree() returns 0 when the RSB is found and stores a valid pointer in r. When the lookup fails, it returns -EBADR and leaves r NULL. The current error handling is inverted: if (!error) goto out; As a result, dlm_dump_rsb() is called only when the lookup fails and r is NULL, resulting in a NULL pointer dereference. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 2d90354027ad ("dlm: merge toss and keep hash table lists into one list") Acked-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Danila Chernetsov <listdansp@mail.ru> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2026-09-02dlm: validate lock modes in recovery messagesDanila Chernetsov
The DLM recovery path restores lock state from rcom_lock messages received from remote nodes. The lock modes in these messages are copied directly into the local lkb state without validating that they are within the valid DLM lock mode range. The rest of the DLM code assumes that lkb_rqmode and lkb_grmode contain valid lock modes. In particular, LVB callback handling in dlm_may_skip_callback() uses lock modes as indexes into the dlm_lvb_operations array: dlm_lvb_operations[prev_mode + 1][mode + 1] An invalid lock mode received during recovery could therefore result in an out-of-bounds read during subsequent LVB callback processing. Validate rl_rqmode and rl_grmode before storing them into the local LKB state. This preserves the lock mode invariant required by the rest of the DLM code. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: e7fd41792fc0 ("[DLM] The core of the DLM for GFS2/CLVM") Acked-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Danila Chernetsov <listdansp@mail.ru> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2026-09-02dlm: fix buffer overflow from negative len in dlm_search_rsb_treeJoseph Qi
commit 080e5563f878c ("dlm: validate length in dlm_search_rsb_tree") only checks for len > DLM_RESNAME_MAXLEN, which does not catch negative values. While the input 'len' can be negative and a negative int passed to memcpy() is implicitly converted to a large size_t, causing a stack buffer overflow on the key[] array. Fix this by changing the 'len' parameter type from int to unsigned int. This ensures negative values from callers are implicitly converted to large unsigned values that are caught by the existing len > DLM_RESNAME_MAXLEN check. Acked-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2026-09-02dlm: validate userspace lock resource name lengthSamuel Moelius
The DLM userspace device accepts a flexible resource name after `struct dlm_write_request`. `device_write()` bounded the total write size, but did not verify that `i.lock.namelen` was covered by the bytes actually supplied by the write. A short `DLM_USER_LOCK` request can therefore claim a full `DLM_RESNAME_MAXLEN` resource name while providing no name bytes. The request path later hashes and copies the claimed name length, reading past the `memdup_user_nul()` allocation. Reject non-conversion lock requests whose claimed resource name length exceeds the flexible name payload supplied with the write. Valid lock requests with complete names are unchanged. Track the payload length before compat conversion so 32-bit requests keep using their own request header size. Assisted-by: Codex:gpt-5.5-cyber-preview Acked-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2026-09-02dlm: require CAP_SYS_ADMIN for dlm-monitor deviceHaofeng Li
monitor_device_open() in fs/dlm/user.c performs only atomic_inc(&dlm_monitor_opened) and sets dlm_monitor_unused = 0; it does no capability check. monitor_device_close() does atomic_dec_and_test(&dlm_monitor_opened) and, when the count reaches zero, calls dlm_stop_lockspaces() — which stops every lockspace on the node. The miscdevice is also registered with no .mode field. Attack chain (when the device node is reachable by an unprivileged opener — see mitigation note below): 1. attacker open("/dev/dlm-monitor") with no cap check; the global counter goes 0 -> 1 2. attacker close(fd); atomic_dec_and_test reaches zero again and dlm_stop_lockspaces() runs -> every DLM lockspace on the local node is stopped. Other cluster members then observe the node losing its lockspaces (membership / recovery side effects), so the impact is not strictly local to GFS2 / OCFS2 / lvmlockd / cluster-md workloads on this node. variant: attacker holds the fd open indefinitely to suppress the intended stop when dlm_controld later closes its own fd (inverse abuse — recovery / shutdown stalls) Mitigation: devtmpfs creates /dev/dlm-monitor as 0600 root:root on a stock kernel, so unprivileged open is blocked by the node mode, not by a kernel cap check. The gap is real wherever the node is reachable (udev MODE=0666, container bind-mount, fd via SCM_RIGHTS, or any setup where dlm_controld shares its monitor fd). Reproduction (kernel 7.2.0-rc3, dlm loaded, no live lockspace): # ./exploit_h3 # as root [*] lockspace devices present: 0 [!!!] AUTH BYPASS: opened /dev/dlm-monitor, no cap check (fd=3) [VULNERABLE] monitor open auth bypass demonstrated $ setpriv --reuid 65534 --regid 65534 ./exploit_h3 [OK ] open denied: Permission denied # node 0600, not cap check The destructive close path is opt-in in the PoX (--i-know-it-stops-lockspaces); we did not drive it here. Driving the close path on a node with active lockspaces would stop them; on this throw-away node there are none, but we keep the opt-in gate so the same PoX is safe to re-run on production-like clusters. Fix: gate monitor_device_open() on capable(CAP_SYS_ADMIN) and set .mode = 0600 on monitor_device, matching the dlm_controld-only intended usage. Acked-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Haofeng Li <lihaofeng@kylinos.cn> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2026-09-02dlm: gate dlm_plock device on CAP_SYS_ADMINHaofeng Li
fs/dlm/plock.c registers /dev/dlm_plock via a miscdevice whose file_operations has no .open callback and whose .mode field is unset. The kernel therefore performs no capability check on open, and any process that can open the node becomes an unprivileged plock daemon with full read+write access to the pending-plock queue. Attack chain (when the device node is reachable by an unprivileged opener — see mitigation note below): 1. attacker open("/dev/dlm_plock") succeeds with no cap check 2. dev_read() drains pending plock requests straight to user space, leaking dlm_plock_info fields: fsid, number (resource id / inode), start, end, owner, pid, ex, wait 3. dev_write() matches an attacker-supplied dlm_plock_info against a pending op on recv_list (matched on fsid+number+ owner+pid+start+end+ex+wait) and memcpy()'s it into the in-kernel op, including a forged .rv == 0 4. when a matched op exists, the forged result is then applied: for async ops (op->data != NULL), dlm_plock_callback() runs posix_lock_file(); for sync ops, the requester wakes and proceeds as if the cluster had granted the lock. Either way the requester ends up holding a POSIX lock without a real DLM grant, or sees attacker-chosen rv that breaks lock correctness. With no pending op on recv_list, dev_write() still returns sizeof(info) but does nothing beyond a pr_debug ("dlm dev_write no op ...") — so a syntactically accepted write does not by itself prove an applied grant. Mitigation: on a stock kernel, devtmpfs creates /dev/dlm_plock as 0600 root:root, so steps 1-4 are only reachable where the node is exposed to a less privileged principal — e.g. udev MODE=0666, container bind-mount of the node, or an fd passed via SCM_RIGHTS. The in-kernel capability gap is real regardless of node mode. Reproduction (kernel 7.2.0-rc3, dlm loaded): # ./exploit_h2 # as root [*] node /dev/dlm_plock mode=0600 uid=0 gid=0 [!!!] AUTH BYPASS: opened with no capability check (fd=3) [!!!] FORGE ACCEPTED: kernel accepted forged plock result (rv=0); pending ops are grant-forgeable [VULNERABLE] open + read-leak + grant-forge demonstrated The "FORGE ACCEPTED" line means dev_write() returned sizeof(info), i.e. the write path is reachable and the version check passed; it does not by itself mean a grant was applied. Demonstrating an actual forged grant requires a concurrent plock op on recv_list to match against. $ setpriv --reuid 65534 --regid 65534 ./exploit_h2 [OK ] open denied: Permission denied # devtmpfs 0600, not a kernel cap check Fix: add a .open callback that requires CAP_SYS_ADMIN, and set .mode = 0600 on the miscdevice so the explicit expectation matches the devtmpfs default and survives future defaults. Acked-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: Haofeng Li <lihaofeng@kylinos.cn> Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David Teigland <teigland@redhat.com>
2026-09-02afs: Clear stale peer app data after address list changesChengfeng Ye
afs_fs_probe_fileserver() fetches the current endpoint state under server->fs_lock, but leaves old_alist as NULL. Consequently, afs_set_peer_appdata() treats every address list replacement as initial setup and only binds the new peers; it never unbinds peers removed from the old list. An address refresh can therefore proceed as follows. CPU 0 replaces server S's list and drops Pold without clearing Pold->app_data. The server destroyer then clears only S's current peers and lets S reach its RCU callback. After the callback frees S, CPU 1 handles a callback through an RxRPC connection that still pins Pold, reads Pold->app_data, and calls afs_use_server() on the freed object. KASAN reported: BUG: KASAN: slab-use-after-free in afs_find_server+0x3c/0xa0 Read of size 4 at addr ffff8881013e1af0 by task krxrpcio/7001/74 Call Trace: afs_find_server+0x3c/0xa0 afs_rx_new_call+0x15c/0x390 rxrpc_new_incoming_call+0x97c/0x1730 rxrpc_input_packet.constprop.0+0xd03/0xec0 rxrpc_io_thread+0x967/0x1640 Allocated by task 93: afs_lookup_server+0x1a7/0x14c0 afs_alloc_server_list+0x43f/0xb60 afs_create_volume+0x923/0x1490 afs_get_tree+0x1c6/0x10a0 Freed by task 0: kfree+0x131/0x3c0 rcu_core+0x50a/0x1850 Last potentially related work creation: __call_rcu_common.constprop.0+0x71/0xa10 afs_put_server+0x213/0x2b0 Preserve old->addresses for the peer app-data update so that removed peers are cleared before the endpoint state is replaced. Also advance both cursors when the old and new lists share a peer; activating the old/new comparison without this would otherwise loop forever on the shared entry. Fixes: 40e8b52fe8c8 ("afs: Use the per-peer app data provided by rxrpc") Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com> Signed-off-by: Qi Zhang <marsy12010123@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260902121024.3328255-5-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-02afs: Fix incorrect free in candidate cleanup in afs_lookup_server()David Howells
Fix afs_lookup_server() to not free an existing server's endpoint state when cleaning up a candidate server. The candidate record doesn't have an endpoint state yet at this point, so the free for that can just be removed. Fixes: 4882ba78574e ("afs: Fix afs_server ref accounting") Link: https://sashiko.dev/#/patchset/20260729160108.2031453-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260902121024.3328255-4-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-02afs: Fix double-unmap of directory blockDavid Howells
Fix afs_edit_dir_remove() to use a cleanup function to unmap the block pointed to by afs_dir_iter::block if it's left pointing to something rather than manually kunmapping the blocks. Manually kunmapping without clearing iter.blocks can result in a double-kunmap if afs_dir_find_block() is called twice in a row (which would be the case if the block being modified is not first in the hash chain). Fixes: a5b5beebcf96 ("afs: Use the contained hashtable to search a directory") Closes: https://sashiko.dev/#/patchset/20260716103030.3065561-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260902121024.3328255-3-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-02afs: Fix missing kunmap in afs_dir_search_bucket()David Howells
Fix afs_dir_search_bucket() to kunmap the block it's using in the "bad:" path. Fixes: a5b5beebcf96 ("afs: Use the contained hashtable to search a directory") Closes: https://sashiko.dev/#/patchset/20260716103030.3065561-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260902121024.3328255-2-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
2026-09-02ceph: apply nearfull_sync option on remountAlex Markuze
ceph_parse_mount_param() stores nearfull_sync / nonearfull_sync on the temporary fs_context options, but ceph_reconfigure_fc() never copied CEPH_MOUNT_OPT_NEARFULL_SYNC onto the live mount. Remount therefore succeeded while writes and /proc/mounts kept the original-mount flag. Apply the flag the same way as ASYNC_DIROPS and SPARSEREAD so remount can enable or disable NEARFULL IOCB_DSYNC promotion. Fixes: c7a12c20bfba ("ceph: make nearfull sync writes opt-in") Signed-off-by: Alex Markuze <amarkuze@redhat.com> Reviewed-by: Xiubo Li <xiubo.li@clyso.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2026-09-02ceph: lock mutex in ceph_mds_check_access()Max Kellermann
MDS session OPEN handling replaces mdsc->s_cap_auths under mdsc->mutex, freeing the previous array and its strings. ceph_mds_check_access() traverses this array without holding the mutex. A concurrent session reopen can therefore free the array while it is being inspected, resulting in a use-after-free like this: Unable to handle kernel paging request at virtual address 003aaad64b2c8bb9 [...] Internal error: Oops: 0000000096000004 [#1] SMP Modules linked in: CPU: 56 UID: 2953037534 PID: 1253231 Comm: php-cgi8.4 Not tainted 6.18.45-i2-ampere #1146 NONE [..] pc : ceph_mds_check_access+0xd4/0x550 lr : ceph_mds_check_access+0xc8/0x550 [...] Call trace: ceph_mds_check_access+0xd4/0x550 (P) ceph_atomic_open+0x138/0xbe8 path_openat+0xa24/0xfa8 do_filp_open+0x94/0x158 do_sys_openat2+0x88/0xf8 Cc: stable@vger.kernel.org Fixes: 596afb0b8933 ("ceph: add ceph_mds_check_access() helper") Signed-off-by: Max Kellermann <max.kellermann@ionos.com> Reviewed-by: Alex Markuze <amarkuze@redhat.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2026-09-02ksmbd: fix tree connection use-after-free in smb2_tree_connect()Cen Zhang (Microsoft Security FORGE Labs)
ksmbd_tree_conn_connect() publishes a new tree connection in sess->tree_conns with a single reference and returns its pointer to smb2_tree_connect(). The handler continues to initialize the object and build the response after publication. A concurrent session logoff can erase the connection and drop that reference, freeing the object while the handler still uses it. BUG: KASAN: slab-use-after-free in smb2_tree_connect+0xe3d/0xf90 smb2_tree_connect (fs/smb/server/smb2pdu.c:2872) handle_ksmbd_work process_one_work worker_thread kthread After xa_store() succeeds, take a second reference before releasing tree_conns_lock. The original reference belongs to the xarray entry and the second belongs to the creating smb2_tree_connect() handler. Keep the references balanced in every path: - On normal exit or an error after publication, smb2_tree_connect() drops its creator reference. Error cleanup also calls ksmbd_tree_conn_disconnect(), which drops the xarray reference only if it removes the exact entry. - SMB2 TREE_DISCONNECT uses the same helper to remove the entry and drop its xarray reference. The request's existing lookup reference remains owned by the request and is released by the existing cleanup. - Session LOGOFF removes each entry and drops its xarray reference. If it wins the race, later cleanup sees that the entry is gone and does not drop that reference again. To enforce this ownership, claim the disconnected state and erase the exact entry atomically under tree_conns_lock. This guarantees one drop for the xarray reference and one drop by each in-flight user, regardless of which teardown path wins. If logoff removes the entry before initialization completes, fail the connect instead of marking the detached object TREE_CONNECTED. Fixes: 33b235a6e6eb ("ksmbd: fix race condition between tree conn lookup and disconnect") Reported-by: Xiang Mei (Microsoft) <xmei5@asu.edu> Cc: AutonomousCodeSecurity@microsoft.com Cc: stable@vger.kernel.org Signed-off-by: Cen Zhang (Microsoft Security FORGE Labs) <cenzhang@linux.microsoft.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-02ksmbd: validate COPYCHUNK source and target rangesAlon Shakevsky
ksmbd_vfs_copy_file_ranges() rejects negative source offsets in the copy loop, but it does not validate target offsets. It also calculates lock and overlap endpoints before ensuring that either range fits within MAX_LFS_FILESIZE. When the target is an alternate data stream, the buffered path passes a negative target offset to ksmbd_vfs_stream_write(). Let n be Length and let -d be TargetOffset, where 0 < d < n <= XATTR_SIZE_MAX. For an empty stream, the writer allocates n - d bytes, then copies n bytes starting d bytes before the allocation. An authenticated SMB client can control d and the source data, overwrite kernel heap memory, and crash the host. Validate both ranges before lock, overlap, or I/O calculations. Fixes: 8482150a0743 ("ksmbd: support copychunk for alternate data streams") Assisted-by: Antiproof:GPT-5.6-Sol Signed-off-by: Alon Shakevsky <shakevsky@berkeley.edu> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-02ksmbd: fix use-after-free in oplock break notificationAbdifatah Suruur
smb2_oplock_break_noti() reads opinfo->conn without any lock and dereferences it after two allocations which may sleep. When the durable handle owning the oplock is disconnected, session_fd_check() clears opinfo->conn and drops its conn reference under ci->m_lock, and the last ksmbd_conn_put() frees the connection. A break triggered by another connection that races with the teardown can then resurrect the freed connection: ksmbd_conn_get() is a plain atomic_inc, and the queued break work later dereferences the stale conn via ksmbd_conn_write(), a use-after-free reachable by any authenticated client holding a durable batch oplock. Thread the caller's inode into the notification path instead of taking a new reference on it. Every caller of oplock_break() already holds a live ksmbd_file (or an explicit ksmbd_inode_lookup_lock() reference, in the parent lease break paths) on the inode that owns the break target's oplock list, so ci cannot be freed during the call, and its lock can be taken without dereferencing opinfo->o_fp, which a concurrent close may free. Select and pin the connection under ci->m_lock, the same lock session_fd_check() and ksmbd_reopen_durable_fd() use to update opinfo->conn, so a concurrent detach either loses the race to the clear or keeps the connection alive until the notification work releases it. Transfer the reference to the work item and release it on allocation failures. Fixes: b003086d7696 ("ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers") Cc: stable@vger.kernel.org Signed-off-by: Abdifatah Suruur <suruurism@gmail.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-02ksmbd: fix sparc build with atomic work stateNamjae Jeon
Use an unsigned int for the work state so xchg() uses a supported 4-byte operation on sparc. Fixes: d12168084c8c ("ksmbd: safely drain sessions during logoff") Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202609021157.8f7Wx34I-lkp@intel.com/ Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
2026-09-02fuse: fall back to copy_splice_read() on FOPEN_DIRECT_IOMiklos Szeredi
Yafang Shao reports: "After upgrading the kernel from 6.1.y to 6.18.y on production servers, some containers failed to read lxcfs data. The root cause is that our lxcfs is still at the old v3.0.4, which does not include commit 25982f5 ("Set the file size to 4k") [0]. Between 6.1.y and 6.18.y, the FUSE splice_read path was converted from generic_file_splice_read() to filemap_splice_read() by commit 2cb1e08985e3 ("splice: Use filemap_splice_read() instead of generic_file_splice_read()"). Unlike generic_file_splice_read(), filemap_splice_read() strictly checks i_size and refuses to read from zero-size files, which breaks virtual FUSE filesystems like the old lxcfs." Fix by using copy_splice_read() for the FOPEN_DIRECT_IO case, just like the VFS does for DAX and O_DIRECT files. Reported-by: Yafang Shao <laoar.shao@gmail.com> Closes: https://lore.kernel.org/all/20260706025705.58301-1-laoar.shao@gmail.com/ Reported-by: Changyuan Lyu <changyuanl@google.com> Closes: https://lore.kernel.org/all/20260901213412.1763253-1-changyuanl@google.com/ Fixes: 2cb1e08985e3 ("splice: Use filemap_splice_read() instead of generic_file_splice_read()") Tested-and-acked-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-09-02fuse: don't bump attr_version for async direct read completionJingbo Xu
The attr_version counter should only be incremented when cached attributes are actually modified (as documented in commit 1fb69e781729 ("fuse: fix race between getattr and write")). Async direct reads do not modify any cached inode attributes (size, mtime, ctime), so bumping attr_version in fuse_aio_complete() for reads is incorrect. This unconditional bump causes a livelock when auto_inval_data is enabled together with writeback_cache: fuse_cache_read_iter() issues a FUSE_GETATTR before every read, but by the time the response arrives, an async DIO read completion has already incremented fi->attr_version past the snapshot taken before the request. The GETATTR result is then discarded (attr_version race), fi->i_time is never refreshed, and every subsequent read triggers yet another GETATTR -- creating an infinite loop of useless round-trips. Fix this by only bumping attr_version for write completions, consistent with the synchronous DIO write path (fuse_write_update_attr) and the cached write path. Fixes: 01e9d11a3e79 ("fuse: add support of async IO") Reviewed-by: Horst Birthelmer <hbirthelmer@ddn.com> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-09-02fuse: mark DAX VMA page protections as decryptedPunit Salian
In confidential computing guest environments (such as AMD SEV-SNP or Intel TDX), direct memory access (DAX) mappings between the guest kernel and host-backed FUSE/virtiofs shared memory regions must be accessed using shared (decrypted) page protections. Modify fuse_dax_mmap() to apply pgprot_decrypted() to vma->vm_page_prot when establishing FUSE DAX memory mappings. This ensures guest page table entries for shared DAX buffers are explicitly marked as decrypted, preventing memory encryption faults when accessing host-shared DAX memory. Signed-off-by: Punit Salian <psalian@google.com> Acked-by: Pankaj Gupta <pankaj.gupta@amd.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-09-02fuse: don't fill in.h.pid in case args->nocreds is setMiklos Szeredi
Commit 794e811d1443 ("fuse: split out filesystem part of request sending") alters the pid sent on force && nocreds requests. Previously these allocated a zeroed request and skipped fuse_force_creds(), so they went out with in.h.pid == 0. In fuse_fill_creds(), args->pid is now set before the nocreds early return, and fuse_args_to_req() copies it unconditionally - so writeback, release, and DESTROY requests now report the triggering (often kernel-worker) pid instead of 0. Move the nocreds check above setting args->pid. Also remove the WARN_ON(!args->nocreds) from the !args->force branch, since it's obviously not going to be triggered. Reported-by: David CARLIER <devnexen@gmail.com> Closes: https://lore.kernel.org/all/CA+XhMqye_NBihcadRTU=w4xAfrdY9rsMB3oHF5+bwHukkjHMoQ@mail.gmail.com/ Fixes: 794e811d1443 ("fuse: split out filesystem part of request sending") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-09-02fuse: allow FUSE_SYNCFS for privileged userspace serversJimmy Zuber
Propagating syncfs()/sync() to a FUSE server via FUSE_SYNCFS lets the server flush its own cached or intermediate state when userspace asks the filesystem to sync. This is currently enabled only for virtiofs and fuseblk, because an untrusted server can use it to stall sync() indefinitely (see commit 2d82ab251ef0 ("virtiofs: propagate sync() to file server"), and commit d3906d8f3cee ("fuse: enable FUSE_SYNCFS for all fuseblk servers")). Both of those mount types require host privilege to set up, so the server is trusted not to abuse it. There is nothing virtiofs- or block-specific about wanting to handle syncfs(), though. A plain /dev/fuse server is just as entitled to participate in the sync() path -- so that data it has buffered reaches stable storage when the user asks for it -- provided it is equally trusted. The trust property that virtiofs and fuseblk satisfy is that neither can be mounted without CAP_SYS_ADMIN in the initial user namespace (neither sets FS_USERNS_MOUNT). A plain fuse mount does set FS_USERNS_MOUNT, so its existence guarantees no such privilege; the privilege has to be checked rather than assumed. Add an opt-in INIT flag, FUSE_HAS_SYNCFS, and honor it only when the server opened /dev/fuse with CAP_SYS_ADMIN in the initial user namespace, recorded at mount time via file_ns_capable(). This is the same privilege that mounting virtiofs or fuseblk requires, applied to the process that actually services (and could stall) the connection. Checking the device opener's capability -- rather than the mount's user namespace -- avoids treating an unprivileged server that merely happens to run in the initial user namespace (e.g. a normal sshfs mount) as trusted. The flag is only advertised to servers that pass this check, so an unprivileged server is never invited to opt in (and is ignored by fuse_syncfs_enable() if it sets the flag anyway). Signed-off-by: Jimmy Zuber <jamz@amazon.com> Assisted-by: Claude:claude-opus-4-8 [Claude-Code] Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-09-02fuse: ioctl: remove unnecessary comparison in fuse_setup_measure_verity()Ali Nasrollahi
Clang reports a warning in fuse_setup_measure_verity() when comparing the __u16 digest_size with SIZE_MAX minus the size of struct fsverity_digest: warning: result of comparison of constant 18446744073709551611 with expression of type '__u16' (aka 'unsigned short') is always false [-Wtautological-constant-out-of-range-compare] This was first observed while building an x86_64 kernel with Clang and W=1. Since -Werror was enabled in my build, the warning caused the build to fail. The same warning can also be reproduced with the same build options using tinyconfig with FUSE enabled, so this is not specific to the kernel configuration used in the original build. The comparison is between the 16-bit digest_size and a size_t-sized constant. Since this comparison cannot be true, remove it. Signed-off-by: Ali Nasrollahi <A.Nasrolahi01@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2026-09-02erofs: preserve LZMA decoders on resize failureNikhil Gurudasani
The pool-resize path frees each stream's old decoder before allocating its replacement. If an allocation fails after some streams have already been replaced, the failed stream is put back on the list with state == NULL. z_erofs_lzma_max_dictsize is still advanced as if the whole pool had been resized. An existing LZMA mount can select the broken stream and pass NULL to xz_dec_microlzma_reset(). A retry at the same size also skip another resize attempt. Since the global maximum was advanced, thus, the invalid state is left unrepaired. Allocate each replacement before freeing the old decoder, temporarily retaining one old decoder during allocation. Stop at the first failure and advance z_erofs_lzma_max_dictsize only after all streams satisfy the request. Record each stream's dictionary capacity so retries can skip streams already enlarged before a partial failure. Fixes: 622ceaddb764 ("erofs: lzma compression support") Cc: stable@vger.kernel.org Signed-off-by: Nikhil Gurudasani <nikhilgurudasani314@gmail.com> Reviewed-by: Gao Xiang <xiang@kernel.org> Signed-off-by: Gao Xiang <xiang@kernel.org>
2026-09-01configfs: move CONFIGFS_MAGIC definition to magic.hFrederick Lawler
IMA shouldn't measure or appraise configfs, but currently does because it's missing from the default exclusion policies. Move CONFIGFS_MAGIC to magic.h to expose the file system's magic to IMA, as well as other userland applications. Suggested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Frederick Lawler <fred@cloudflare.com> Acked-by: Breno Leitao <leitao@debian.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2026-09-02erofs: add sysfs feature entry for xattr prefixesJingbo Xu
Let /sys/fs/erofs/features/xattr_prefixes advertise that this kernel supports the EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES on-disk format. Fixes: 6a318ccd7e08 ("erofs: enable long extended attribute name prefixes") Cc: stable@vger.kernel.org # 6.4+ Reviewed-by: Gao Xiang <xiang@kernel.org> Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com> Signed-off-by: Gao Xiang <xiang@kernel.org>
2026-09-02btrfs: preserve the compression property when other inode flags changeSam Ho
Setting the compression property on an inode also sets BTRFS_INODE_COMPRESS on it, and btrfs_inode_flags_to_fsflags() reports that back as FS_COMPR_FL to FS_IOC_GETFLAGS. chattr(1), like any other FS_IOC_SETFLAGS caller, reads the current flags, flips only the bit the user asked for and writes the whole set back, so a request as unrelated as "chattr +i" reaches btrfs_fileattr_set() with FS_COMPR_FL set. btrfs_fileattr_set() takes that as a request to enable compression and overwrites the compression property with the algorithm from the mount options, falling back to zlib when the filesystem was not mounted with -o compress. The algorithm the user selected is silently replaced: # btrfs property set /mnt/foo compression zstd # btrfs property get /mnt/foo compression compression=zstd # chattr +i /mnt/foo # btrfs property get /mnt/foo compression compression=zlib Every chattr operation triggers this, not just +i, and directories are affected as well, so files created afterwards inherit the wrong algorithm too. On a filesystem mounted with -o compress=lzo the property is replaced with lzo instead. Recovering needs a chattr -i first, because the immutable flag rejects the setxattr that "btrfs property set" issues. Prefer the algorithm recorded in the compression property and only fall back to the mount default when there is no property, so that unrelated flag changes no longer overwrite the user's choice. Inodes that have the compress flag set but no property still get the default, so they behave as before. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Sam Ho <samho@synology.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: restore active device pointers after failed sproutGuanghui Yang
btrfs_init_new_device() switches latest_dev and possibly s_bdev from the seed device to the new sprout device before creating the first writable chunks. If chunk creation or the subsequent sprout setup fails, the error path releases the new device without switching those pointers back. btrfs_show_devname() can then dereference the freed latest_dev and crash. Restore the active device pointers to the latest seed device before removing and releasing the failed sprout device. Fixes: b7cb29e666fe ("btrfs: update latest_dev when we create a sprout device") Assisted-by: Codex:gpt-5 Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Guanghui Yang <3497809730@qq.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: detach failed sprout device from transaction update listGuanghui Yang
When creating the first metadata chunk for a sprout filesystem, create_chunk() adds the new device to the transaction dev_update_list through device->post_commit_list. If the subsequent system chunk creation fails, btrfs_init_new_device() aborts the transaction and releases the device while post_commit_list is still linked. This triggers a warning in btrfs_free_device() and leaves the transaction list referencing freed memory. Detach the device while holding chunk_mutex before releasing it. Fixes: bbbf7243d62d ("btrfs: combine device update operations during transaction commit") Assisted-by: Codex:gpt-5 Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Guanghui Yang <3497809730@qq.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-02btrfs: clean up target device if block group marking failsGuanghui Yang
btrfs_dev_replace_start() adds the replacement target to the device list before marking block groups to copy. If marking fails, returning directly leaves the target linked and keeps the device accounting incremented. Jump to the existing cleanup path so the target device is removed and released on failure. The issue was found by a failure-path metadata residual analyzer and verified with targeted failure injection on v6.14. Assisted-by: Codex:gpt-5 Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Guanghui Yang <3497809730@qq.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2026-09-01Merge tag 'cifs-fixes-7.3-rc2' of https://git.manguebit.org/linuxLinus Torvalds
Pull smb client fixes from Paulo Alcantara: - Fixes for fallocate range operations (insert, collapse, zero, punch hole) The insert range implementation copied overlapping chunks in the wrong direction, corrupting file data on every server except Windows. Several related issues in the same area are also addressed — stale page cache and FS-Cache readback, an integer truncation on large files, missing RLIMIT_FSIZE validation and missing sparse file marking. - Data corruption fixes in the O_TRUNC open path: one where i_size was zeroed before the server confirmed the truncate and another where the lack of locking allowed concurrent buffered writes to be silently discarded - Heap overflow fixes in legacy SMB1 paths: one in extended attribute writes and one in POSIX ACL handling, both exploitable via unprivileged setxattr(2) - Fix for multiuser mount with krb5 failing because the username option was not propagated to new per-user connections - Fix for split debug message in __release_mid() after a printk conversion * tag 'cifs-fixes-7.3-rc2' of https://git.manguebit.org/linux: smb: client: reject SetEA requests that do not fit the request buffer smb: client: fix data corruption with concurrent writes and O_TRUNC cifs: don't update i_size in cifs_do_truncate without a cached handle smb: client: fix heap overflow in cifs_do_set_acl() smb: client: fix multiuser mount with krb5 smb: client: transport: Fix debug printing in __release_mid() smb/client: invalidate fscache for fallocate range operations smb/client: fix stale page cache in insert/collapse range smb/client: fix integer truncation in collapse range smb/client: fix data corruption in emulated insert range smb/client: mark file sparse before emulating insert range smb/client: validate new EOF for zero range smb/client: validate new EOF for insert range cifs: add revalidation on FSCTL failure in smb2_duplicate_extents()
2026-09-01Merge tag 'ksmbd-for-7.3-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/smb Pull smb server fixes from Namjae Jeon: - Prevent unintended data exposure by clearing pipe compound padding and the response buffer - Initialize missing fields in FS_OBJECT_ID_INFORMATION, FS_CONTROL_INFORMATION, and FS_POSIX_INFORMATION - Propagate DACL parsing and allocation failures so malformed security descriptors are rejected - Rate-limit errors for unmapped SIDs to prevent kernel log flooding - Drain multichannel sessions during LOGOFF, wake deferred locks and cancellable requests, and ensure cancellation callbacks run only once - Fix listener kthread reference handling and teardown ordering during netdevice events - Validate normalized-name and IPC share configuration response lengths - Update the KSMBD MAINTAINERS entry and add Paulo Alcantara as an SMBDIRECT co-maintainer * tag 'ksmbd-for-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/smb: ksmbd: validate normalized name response length ksmbd: fix listener task lifetime on netdev events ksmbd: prevent out-of-bounds reads in share config responses ksmbd: rate limit unmapped SID errors ksmbd: propagate DACL parsing errors ksmbd: zero pipe read compound padding ksmbd: safely drain sessions during logoff MAINTAINERS: Update the KSMBD entry MAINTAINERS: Add Paulo Alcantara as an SMBDIRECT co-maintainer ksmbd: fill in FileSysIdentifier in FS_POSIX_INFORMATION ksmbd: initialize FileSystemControlFlags in FS_CONTROL_INFORMATION ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in
2026-09-01kernfs: preserve security xattrs without allocating iattrsHengyu Liang
Commit d5e81a5650b5 ("kernfs: avoid iattr allocation in listxattr") made kernfs_iop_listxattr() return an empty list when the kernfs node has no allocated kernfs_iattrs. However, this also skips security xattr names provided by simple_xattr_list(). As of now, applications can retrieve the SELinux label of a sysfs file with getxattr(), but cannot do it through listxattr(). A similar issue happened before in commit b09e0fa4b4ea ("tmpfs: implement generic xattr support"). It was fixed by commit 8b0ba61df5a1c ("fs/xattr.c: fix simple_xattr_list to always include security.* xattrs"). Perhaps this recent commit needs a fix as well. The issue can be reproduced with a simple python program: python3 - <<'PY' import os path = "/sys/kernel/warn_count" print("getxattr:", os.getxattr(path, "security.selinux")) print("listxattr:", os.listxattr(path)) PY Before commit d5e81a5650b5 ("kernfs: avoid iattr allocation in listxattr"), the result is: getxattr: b'system_u:object_r:sysfs_t:s0\x00' listxattr: ['security.selinux'] After that commit, the result is: getxattr: b'system_u:object_r:sysfs_t:s0\x00' listxattr: [] This patch will keep listxattr() consistent with getxattr() when security xattrs are available. Fixes: d5e81a5650b5 ("kernfs: avoid iattr allocation in listxattr") Signed-off-by: Hengyu Liang <hengyul@cs.unc.edu> Acked-by: Tejun Heo <tj@kernel.org> Link: https://patch.msgid.link/20260822051705.1761850-1-hengyul@cs.unc.edu Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-09-01ext2: annotate block-mapping helpers as requiring truncate_mutexTimothy Day
The indirect-block mapping helpers in inode.c all run under the inode's truncate_mutex. ext2_find_goal(), ext2_alloc_blocks(), ext2_alloc_branch() and ext2_splice_branch() are reached only from ext2_get_blocks() while it holds the mutex. ext2_find_shared(), ext2_free_data() and ext2_free_branches() are called from __ext2_truncate_blocks() while it holds the mutex. Add __must_hold() annotations for the Clang's context analysis to reflect this. Signed-off-by: Timothy Day <timday@thelustrecollective.com> Acked-by: Marco Elver <elver@google.com> Link: https://patch.msgid.link/20260811160336.782342-7-timday@thelustrecollective.com Signed-off-by: Jan Kara <jack@suse.cz>
2026-09-01ext2: annotate ext2_init_block_alloc_info() as requiring truncate_mutexTimothy Day
ext2_init_block_alloc_info() sets up the inode's block reservation info and is already documented as needing truncate_mutex protection. Express that with __must_hold() for Clang's context analysis. Both callers (ext2_get_blocks() and ext2_ioctl()) already hold truncate_mutex. Signed-off-by: Timothy Day <timday@thelustrecollective.com> Acked-by: Marco Elver <elver@google.com> Link: https://patch.msgid.link/20260811160336.782342-6-timday@thelustrecollective.com Signed-off-by: Jan Kara <jack@suse.cz>
2026-09-01ext2: mark s_mount_state as guarded by s_lockTimothy Day
s_mount_state tracks the filesystem's mount/error state and is protected by s_lock everywhere it is accessed. Annotate it with __guarded_by() for Clang's context analysis. ext2_setup_super() reads s_mount_state and is called with s_lock held from the remount path, so annotate it with __must_hold(). There are two accesses (the initial read in ext2_fill_super() and the setup_super() call) in the mount flow. This is before the superblock is live, so no concurrent access should be possible. Convert the spinlock initialization to use guard(spinlock_init) to prevent warnings on the writes later in initialization. Signed-off-by: Timothy Day <timday@thelustrecollective.com> Acked-by: Marco Elver <elver@google.com> Link: https://patch.msgid.link/20260811160336.782342-5-timday@thelustrecollective.com Signed-off-by: Jan Kara <jack@suse.cz>
2026-09-01ext2: mark statfs overhead cache as guarded by s_lockTimothy Day
s_overhead_last and s_blocks_last cache the filesystem overhead computation and are only ever accessed in ext2_statfs() under s_lock. Annotate them with __guarded_by() for Clang's context analysis. Signed-off-by: Timothy Day <timday@thelustrecollective.com> Acked-by: Marco Elver <elver@google.com> Link: https://patch.msgid.link/20260811160336.782342-4-timday@thelustrecollective.com Signed-off-by: Jan Kara <jack@suse.cz>