syzbot reported a WARNING in nilfs_rmdir. [1] The inode is used twice by the same task to unmount and remove directories ".nilfs" and "file0", it trigger warning in nilfs_rmdir. Avoid to this issue, check i_size and i_nlink in nilfs_iget(), if they are both 0, it means that this inode has been removed, and iput is executed to reclaim it. [1] WARNING: CPU: 1 PID: 5824 at fs/inode.c:407 drop_nlink+0xc4/0x110 fs/inode.c:407 Modules linked in: CPU: 1 UID: 0 PID: 5824 Comm: syz-executor223 Not tainted 6.12.0-syzkaller-12113-gbcc8eda6d349 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:drop_nlink+0xc4/0x110 fs/inode.c:407 Code: bb 70 07 00 00 be 08 00 00 00 e8 57 0b e6 ff f0 48 ff 83 70 07 00 00 5b 41 5c 41 5e 41 5f 5d c3 cc cc cc cc e8 9d 4c 7e ff 90 <0f> 0b 90 eb 83 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c 5c ff ff ff RSP: 0018:ffffc900037f7c70 EFLAGS: 00010293 RAX: ffffffff822124a3 RBX: 1ffff1100e7ae034 RCX: ffff88807cf53c00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff82212423 R09: 1ffff1100f8ba8ee R10: dffffc0000000000 R11: ffffed100f8ba8ef R12: ffff888073d701a0 R13: 1ffff1100e79f5c4 R14: ffff888073d70158 R15: dffffc0000000000 FS: 0000555558d1e480(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555558d37878 CR3: 000000007d920000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> nilfs_rmdir+0x1b0/0x250 fs/nilfs2/namei.c:342 vfs_rmdir+0x3a3/0x510 fs/namei.c:4394 do_rmdir+0x3b5/0x580 fs/namei.c:4453 __do_sys_rmdir fs/namei.c:4472 [inline] __se_sys_rmdir fs/namei.c:4470 [inline] __x64_sys_rmdir+0x47/0x50 fs/namei.c:4470 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reported-and-tested-by: syzbot+9260555647a5132edd48@xxxxxxxxxxxxxxxxxxxxxxxxx Closes: https://syzkaller.appspot.com/bug?extid=9260555647a5132edd48 Signed-off-by: Edward Adam Davis <eadavis@xxxxxx> --- fs/nilfs2/inode.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index cf9ba481ae37..254a5e46f8ea 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -544,8 +544,15 @@ struct inode *nilfs_iget(struct super_block *sb, struct nilfs_root *root, inode = nilfs_iget_locked(sb, root, ino); if (unlikely(!inode)) return ERR_PTR(-ENOMEM); - if (!(inode->i_state & I_NEW)) + + if (!(inode->i_state & I_NEW)) { + if (!inode->i_size && !inode->i_nlink) { + make_bad_inode(inode); + iput(inode); + return ERR_PTR(-EIO); + } return inode; + } err = __nilfs_read_inode(sb, root, ino, inode); if (unlikely(err)) { -- 2.47.0
