kernel/linux.git/fs/nilfs2, branch v6.12.97

nilfs2: fix backing_dev_info reference leak

2026-07-24T14:10:46+00:00

[ Upstream commit 665f192a2a11384cb7dc1be5f87d16438522a4ed ] setup_bdev_super() already initializes sb->s_bdev and takes a reference on the block device backing_dev_info when assigning sb->s_bdi. nilfs_fill_super() takes another reference to the same backing_dev_info and stores it in sb->s_bdi again. The extra reference is not paired with a matching bdi_put(), since generic_shutdown_super() releases sb->s_bdi only once. Drop the redundant bdi_get() in nilfs_fill_super(). The single reference taken by setup_bdev_super() is enough and is released during superblock shutdown. Fixes: c1e012ea9e83 ("nilfs2: use setup_bdev_super to de-duplicate the mount code") Signed-off-by: Shuangpeng Bai Acked-by: Ryusuke Konishi Reviewed-by: Viacheslav Dubeyko Signed-off-by: Viacheslav Dubeyko Signed-off-by: Sasha Levin

nilfs2: reject CLEAN_SEGMENTS ioctl with out-of-range segment numbers

2026-07-18T14:52:07+00:00

commit 0e7a690fe435f8d5ea3feb7c1d8d73ba7e8b8aa9 upstream. Syzbot reported a hung task in nilfs_transaction_begin() where multiple tasks performing chmod() on a nilfs2 mount blocked for over 143 seconds waiting to acquire ns_segctor_sem for read: INFO: task syz.0.17:5918 blocked for more than 143 seconds. Call Trace: schedule+0x164/0x360 rwsem_down_read_slowpath+0x6d9/0x940 down_read+0x99/0x2e0 nilfs_transaction_begin+0x364/0x710 fs/nilfs2/segment.c:221 nilfs_setattr+0x124/0x2c0 fs/nilfs2/inode.c:921 notify_change+0xc1a/0xf40 chmod_common+0x273/0x4a0 do_fchmodat+0x12d/0x230 The writer holding ns_segctor_sem was a concurrent NILFS_IOCTL_CLEAN_SEGMENTS caller, stuck inside printk while emitting per-element warnings from nilfs_sufile_updatev(): __nilfs_msg+0x373/0x450 fs/nilfs2/super.c:78 nilfs_sufile_updatev+0x21c/0x6d0 fs/nilfs2/sufile.c:186 nilfs_sufile_freev fs/nilfs2/sufile.h:93 [inline] nilfs_free_segments fs/nilfs2/segment.c:1140 [inline] nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1261 [inline] nilfs_segctor_do_construct+0x1f55/0x76c0 nilfs_clean_segments+0x3bd/0xa50 nilfs_ioctl_clean_segments fs/nilfs2/ioctl.c:922 [inline] nilfs_ioctl+0x261f/0x2780 The root cause is that user-supplied segment numbers are not validated before nilfs_clean_segments() begins doing work; the range check on each segnum is performed deep inside the call chain by nilfs_sufile_updatev(), which emits a nilfs_warn() per invalid entry while still holding the segctor lock and the sufile mi_sem. Under load (repeated invocations across multiple mounts saturating the global printk path), the cumulative printk latency keeps ns_segctor_sem held long enough to trip the hung_task watchdog, blocking concurrent operations such as chmod() that need ns_segctor_sem for read. Fix by validating the contents of kbufs[4] in nilfs_clean_segments() immediately after acquiring ns_segctor_sem via nilfs_transaction_lock(). Holding ns_segctor_sem serializes the check against nilfs_ioctl_resize(), which can modify ns_nsegments, so the validation uses a consistent value. Out-of-range segment numbers are rejected with -EINVAL before any segment-cleaning work begins, so the bad entries never reach the per-element diagnostic path inside nilfs_sufile_updatev(). Reported-by: syzbot+62f0f99d2f2bb8e3bbd7@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=62f0f99d2f2bb8e3bbd7 Tested-by: syzbot+62f0f99d2f2bb8e3bbd7@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Deepanshu Kartikey Fixes: 071cb4b81987 ("nilfs2: eliminate removal list of segments") Signed-off-by: Ryusuke Konishi Signed-off-by: Viacheslav Dubeyko Signed-off-by: Greg Kroah-Hartman

nilfs2: reject zero bd_oblocknr in nilfs_ioctl_mark_blocks_dirty()

2026-05-23T11:04:19+00:00

[ Upstream commit be3e5d10643d3be1cbac9d9939f220a99253f980 ] nilfs_ioctl_mark_blocks_dirty() uses bd_oblocknr to detect dead blocks by comparing it with the current block number bd_blocknr. If they differ, the block is considered dead and skipped. However, bd_oblocknr should never be 0 since block 0 typically stores the primary superblock and is never a valid GC target block. A corrupted ioctl request with bd_oblocknr set to 0 causes the comparison to incorrectly match when the lookup returns -ENOENT and sets bd_blocknr to 0, bypassing the dead block check and calling nilfs_bmap_mark() on a non-existent block. This causes nilfs_btree_do_lookup() to return -ENOENT, triggering the WARN_ON(ret == -ENOENT). Fix this by rejecting ioctl requests with bd_oblocknr set to 0 at the beginning of each iteration. [ryusuke: slightly modified the commit message and comments for accuracy] Fixes: 7942b919f732 ("nilfs2: ioctl operations") Reported-by: syzbot+98a040252119df0506f8@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=98a040252119df0506f8 Suggested-by: Ryusuke Konishi Signed-off-by: Deepanshu Kartikey Reported-by: syzbot+466a45fcfb0562f5b9a0@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=466a45fcfb0562f5b9a0 Cc: Junjie Cao Signed-off-by: Ryusuke Konishi Signed-off-by: Viacheslav Dubeyko Signed-off-by: Sasha Levin

nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map

2026-04-22T11:19:03+00:00

commit 4a4e0328edd9e9755843787d28f16dd4165f8b48 upstream. The DAT inode's btree node cache (i_assoc_inode) is initialized lazily during btree operations. However, nilfs_mdt_save_to_shadow_map() assumes i_assoc_inode is already initialized when copying dirty pages to the shadow map during GC. If NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before any btree operation has occurred on the DAT inode, i_assoc_inode is NULL leading to a general protection fault. Fix this by calling nilfs_attach_btree_node_cache() on the DAT inode in nilfs_dat_read() at mount time, ensuring i_assoc_inode is always initialized before any GC operation can use it. Reported-by: syzbot+4b4093b1f24ad789bf37@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=4b4093b1f24ad789bf37 Tested-by: syzbot+4b4093b1f24ad789bf37@syzkaller.appspotmail.com Fixes: e897be17a441 ("nilfs2: fix lockdep warnings in page operations for btree nodes") Signed-off-by: Deepanshu Kartikey Signed-off-by: Ryusuke Konishi Cc: stable@vger.kernel.org Signed-off-by: Viacheslav Dubeyko Signed-off-by: Greg Kroah-Hartman

nilfs2: Fix potential block overflow that cause system hang

2026-02-16T09:18:44+00:00

commit ed527ef0c264e4bed6c7b2a158ddf516b17f5f66 upstream. When a user executes the FITRIM command, an underflow can occur when calculating nblocks if end_block is too small. Since nblocks is of type sector_t, which is u64, a negative nblocks value will become a very large positive integer. This ultimately leads to the block layer function __blkdev_issue_discard() taking an excessively long time to process the bio chain, and the ns_segctor_sem lock remains held for a long period. This prevents other tasks from acquiring the ns_segctor_sem lock, resulting in the hang reported by syzbot in [1]. If the ending block is too small, typically if it is smaller than 4KiB range, depending on the usage of the segment 0, it may be possible to attempt a discard request beyond the device size causing the hang. Exiting successfully and assign the discarded size (0 in this case) to range->len. Although the start and len values in the user input range are too small, a conservative strategy is adopted here to safely ignore them, which is equivalent to a no-op; it will not perform any trimming and will not throw an error. [1] task:segctord state:D stack:28968 pid:6093 tgid:6093 ppid:2 task_flags:0x200040 flags:0x00080000 Call Trace: rwbase_write_lock+0x3dd/0x750 kernel/locking/rwbase_rt.c:272 nilfs_transaction_lock+0x253/0x4c0 fs/nilfs2/segment.c:357 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2569 [inline] nilfs_segctor_thread+0x6ec/0xe00 fs/nilfs2/segment.c:2684 [ryusuke: corrected part of the commit message about the consequences] Fixes: 82e11e857be3 ("nilfs2: add nilfs_sufile_trim_fs to trim clean segs") Reported-by: syzbot+7eedce5eb281acd832f0@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7eedce5eb281acd832f0 Signed-off-by: Edward Adam Davis Signed-off-by: Ryusuke Konishi Cc: stable@vger.kernel.org Signed-off-by: Viacheslav Dubeyko Signed-off-by: Greg Kroah-Hartman

nilfs2: avoid having an active sc_timer before freeing sci

2025-11-24T09:36:00+00:00

commit 9a6b60cb147d53968753a34805211d2e5e08c027 upstream. Because kthread_stop did not stop sc_task properly and returned -EINTR, the sc_timer was not properly closed, ultimately causing the problem [1] reported by syzbot when freeing sci due to the sc_timer not being closed. Because the thread sc_task main function nilfs_segctor_thread() returns 0 when it succeeds, when the return value of kthread_stop() is not 0 in nilfs_segctor_destroy(), we believe that it has not properly closed sc_timer. We use timer_shutdown_sync() to sync wait for sc_timer to shutdown, and set the value of sc_task to NULL under the protection of lock sc_state_lock, so as to avoid the issue caused by sc_timer not being properly shutdowned. [1] ODEBUG: free active (active state 0) object: 00000000dacb411a object type: timer_list hint: nilfs_construction_timeout Call trace: nilfs_segctor_destroy fs/nilfs2/segment.c:2811 [inline] nilfs_detach_log_writer+0x668/0x8cc fs/nilfs2/segment.c:2877 nilfs_put_super+0x4c/0x12c fs/nilfs2/super.c:509 Link: https://lkml.kernel.org/r/20251029225226.16044-1-konishi.ryusuke@gmail.com Fixes: 3f66cc261ccb ("nilfs2: use kthread_create and kthread_stop for the log writer thread") Signed-off-by: Ryusuke Konishi Reported-by: syzbot+24d8b70f039151f65590@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=24d8b70f039151f65590 Tested-by: syzbot+24d8b70f039151f65590@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis Cc: [6.12+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

nilfs2: fix CFI failure when accessing /sys/fs/nilfs2/features/*

2025-09-25T09:13:45+00:00

commit 025e87f8ea2ae3a28bf1fe2b052bfa412c27ed4a upstream. When accessing one of the files under /sys/fs/nilfs2/features when CONFIG_CFI_CLANG is enabled, there is a CFI violation: CFI failure at kobj_attr_show+0x59/0x80 (target: nilfs_feature_revision_show+0x0/0x30; expected type: 0xfc392c4d) ... Call Trace: sysfs_kf_seq_show+0x2a6/0x390 ? __cfi_kobj_attr_show+0x10/0x10 kernfs_seq_show+0x104/0x15b seq_read_iter+0x580/0xe2b ... When the kobject of the kset for /sys/fs/nilfs2 is initialized, its ktype is set to kset_ktype, which has a ->sysfs_ops of kobj_sysfs_ops. When nilfs_feature_attr_group is added to that kobject via sysfs_create_group(), the kernfs_ops of each files is sysfs_file_kfops_rw, which will call sysfs_kf_seq_show() when ->seq_show() is called. sysfs_kf_seq_show() in turn calls kobj_attr_show() through ->sysfs_ops->show(). kobj_attr_show() casts the provided attribute out to a 'struct kobj_attribute' via container_of() and calls ->show(), resulting in the CFI violation since neither nilfs_feature_revision_show() nor nilfs_feature_README_show() match the prototype of ->show() in 'struct kobj_attribute'. Resolve the CFI violation by adjusting the second parameter in nilfs_feature_{revision,README}_show() from 'struct attribute' to 'struct kobj_attribute' to match the expected prototype. Link: https://lkml.kernel.org/r/20250906144410.22511-1-konishi.ryusuke@gmail.com Fixes: aebe17f68444 ("nilfs2: add /sys/fs/nilfs2/features group") Signed-off-by: Nathan Chancellor Signed-off-by: Ryusuke Konishi Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202509021646.bc78d9ef-lkp@intel.com/ Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

nilfs2: reject invalid file types when reading inodes

2025-08-01T08:48:43+00:00

commit 4aead50caf67e01020c8be1945c3201e8a972a27 upstream. To prevent inodes with invalid file types from tripping through the vfs and causing malfunctions or assertion failures, add a missing sanity check when reading an inode from a block device. If the file type is not valid, treat it as a filesystem error. Link: https://lkml.kernel.org/r/20250710134952.29862-1-konishi.ryusuke@gmail.com Fixes: 05fe58fdc10d ("nilfs2: inode operations") Signed-off-by: Ryusuke Konishi Reported-by: syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

nilfs2: do not propagate ENOENT error from nilfs_btree_propagate()

2025-06-19T13:32:01+00:00

[ Upstream commit 8e39fbb1edbb4ec9d7c1124f403877fc167fcecd ] In preparation for writing logs, in nilfs_btree_propagate(), which makes parent and ancestor node blocks dirty starting from a modified data block or b-tree node block, if the starting block does not belong to the b-tree, i.e. is isolated, nilfs_btree_do_lookup() called within the function fails with -ENOENT. In this case, even though -ENOENT is an internal code, it is propagated to the log writer via nilfs_bmap_propagate() and may be erroneously returned to system calls such as fsync(). Fix this issue by changing the error code to -EINVAL in this case, and having the bmap layer detect metadata corruption and convert the error code appropriately. Link: https://lkml.kernel.org/r/20250428173808.6452-3-konishi.ryusuke@gmail.com Fixes: 1f5abe7e7dbc ("nilfs2: replace BUG_ON and BUG calls triggerable from ioctl") Signed-off-by: Ryusuke Konishi Cc: Wentao Liang Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin

nilfs2: add pointer check for nilfs_direct_propagate()

2025-06-19T13:32:01+00:00

[ Upstream commit f43f02429295486059605997bc43803527d69791 ] Patch series "nilfs2: improve sanity checks in dirty state propagation". This fixes one missed check for block mapping anomalies and one improper return of an error code during a preparation step for log writing, thereby improving checking for filesystem corruption on writeback. This patch (of 2): In nilfs_direct_propagate(), the printer get from nilfs_direct_get_ptr() need to be checked to ensure it is not an invalid pointer. If the pointer value obtained by nilfs_direct_get_ptr() is NILFS_BMAP_INVALID_PTR, means that the metadata (in this case, i_bmap in the nilfs_inode_info struct) that should point to the data block at the buffer head of the argument is corrupted and the data block is orphaned, meaning that the file system has lost consistency. Add a value check and return -EINVAL when it is an invalid pointer. Link: https://lkml.kernel.org/r/20250428173808.6452-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20250428173808.6452-2-konishi.ryusuke@gmail.com Fixes: 36a580eb489f ("nilfs2: direct block mapping") Signed-off-by: Wentao Liang Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin