kernel/git/stable/linux.git/fs/nilfs2, branch linux-rolling-lts

nilfs2: fix slab-out-of-bounds in nilfs_direct_propagate after truncation

2026-09-07T15:22:26+00:00

commit 45662dedb8f272ef7f16e69f13424c4bd0399240 upstream. Shuangpeng Bai reported that KASAN detected a slab-out-of-bounds error in nilfs_direct_propagate() during testing. Analysis revealed that after truncating a file, a node block immediately below the B-tree root was not deleted. Instead, it remained in the B-tree node cache in a dirty state. The log writer subsequently detected this block and incorrectly invoked nilfs_direct_propagate() on it, which is designed to handle only data blocks in direct mapping. B-tree nodes in the cache are managed by virtual block numbers, and their logical keys typically exceed the range expected by direct mapping. Consequently, processing such a node as a direct mapping entry triggers a slab-out-of-bounds access. The root cause is that when a B-tree mapping collapses into a direct mapping during truncation, an intermediate node block pointed to by the root node is left behind as garbage instead of being explicitly deleted. This resolves the issue by adding a nilfs_btree_discard() operation to delete the remaining intermediate node block during the conversion. A 'deform' flag is added to the bop_delete interface to explicitly signal that the deletion is part of a mapping transformation. This allows the B-tree mapping implementation to perform the necessary cleanup and discarding of the residual node structure that would be otherwise be left orphaned after the transition. Reported-by: Shuangpeng Bai Closes: https://lore.kernel.org/r/08A3603A-ADB6-484C-9015-9AC1340E6FB8@gmail.com Fixes: 36a580eb489f ("nilfs2: direct block mapping") Cc: stable@vger.kernel.org Signed-off-by: Ryusuke Konishi Signed-off-by: Viacheslav Dubeyko Signed-off-by: Greg Kroah-Hartman

nilfs2: reject invalid block index in GC ioctl

2026-08-27T12:32:50+00:00

commit a1735eae55448bc79c2da6593455791e886f6ed8 upstream. Syzbot reported list corruption caused by a double list_add_tail() call on bh->b_assoc_buffers within nilfs_lookup_dirty_data_buffers(). Analysis revealed that the root cause was the insertion of a page/folio with a page index of ULONG_MAX into the page cache via the GC ioctl. filemap_get_folios_tag(), called by nilfs_lookup_dirty_data_buffers(), repeatedly detects a dirty folio with a page index of ULONG_MAX due to index wrap-around, leading to duplicate processing of dirty buffers. As a preparatory step, the GC ioctl loads the page/folio of the block to be moved during GC and inserts it into the page cache based on information in the nilfs_vdesc structure passed as an argument. Normally, this does not cause issues because the user-space GC library configures the nilfs_vdesc structure properly. However, since there is no range check on the parameters determining the page index, a request with artificially crafted parameters -- such as those generated by Syzbot -- can result in a page/folio being inserted with a page index of ULONG_MAX, triggering the above problem. This resolves the issue by checking the ranges of 'vd_offset' and 'vd_vblocknr' in the nilfs_vdesc structure that determine the page index, thereby preventing the invalid page/folio insertions. Reported-by: syzbot+c37bed40868932d790e9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=c37bed40868932d790e9 Fixes: 7942b919f732 ("nilfs2: ioctl operations") Cc: wuyankun Cc: stable@vger.kernel.org Signed-off-by: Ryusuke Konishi Signed-off-by: Viacheslav Dubeyko Signed-off-by: Greg Kroah-Hartman

nilfs2: Fix return in nilfs_mkdir

2026-07-24T14:15:50+00:00

[ Upstream commit e5925f33e4fa9ee313d481557607adce8e30ed2e ] Return NULL instead of passing zero to ERR_PTR. Fixes smatch warning: - fs/nilfs2/namei.c:261 nilfs_mkdir() warn: passing zero to 'ERR_PTR' Fixes: 88d5baf69082 ("Change inode_operations.mkdir to return struct dentry *") Signed-off-by: Hongling Zeng Signed-off-by: Ryusuke Konishi Signed-off-by: Viacheslav Dubeyko Signed-off-by: Sasha Levin

nilfs2: fix backing_dev_info reference leak

2026-07-24T14:15:47+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

2026-07-18T14:53:22+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()

2026-05-23T11:06:23+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

2026-04-22T11:22:33+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

2026-02-16T09:19:44+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

2025-11-10T05:19:46+00:00

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

Merge branch 'mm-hotfixes-stable' into mm-stable in order to pick up

2025-09-21T21:19:36+00:00

changes required by mm-stable material: hugetlb and damon.