WARNING: CPU: 1 PID: 9426 at fs/inode.c:417 drop_nlink+0xac/0xd0 home/cc/linux/fs/inode.c:417 Modules linked in: CPU: 1 UID: 0 PID: 9426 Comm: syz-executor568 Not tainted 6.14.0-12627-g94d471a4f428 #2 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:drop_nlink+0xac/0xd0 home/cc/linux/fs/inode.c:417 Code: 48 8b 5d 28 be 08 00 00 00 48 8d bb 70 07 00 00 e8 f9 67 e6 ff f0 48 ff 83 70 07 00 00 5b 5d e9 9a 12 82 ff e8 95 12 82 ff 90 &lt;0f&gt; 0b 90 c7 45 48 ff ff ff ff 5b 5d e9 83 12 82 ff e8 fe 5f e6 ff RSP: 0018:ffffc900026b7c28 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8239710f RDX: ffff888041345a00 RSI: ffffffff8239717b RDI: 0000000000000005 RBP: ffff888054509ad0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff9ab36f08 R12: ffff88804bb40000 R13: ffff8880545091e0 R14: 0000000000008000 R15: ffff8880545091e0 FS: 000055555d0c5880(0000) GS:ffff8880eb3e3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f915c55b178 CR3: 0000000050d20000 CR4: 0000000000352ef0 Call Trace: <task> f2fs_i_links_write home/cc/linux/fs/f2fs/f2fs.h:3194 [inline] f2fs_drop_nlink+0xd1/0x3c0 home/cc/linux/fs/f2fs/dir.c:845 f2fs_delete_entry+0x542/0x1450 home/cc/linux/fs/f2fs/dir.c:909 f2fs_unlink+0x45c/0x890 home/cc/linux/fs/f2fs/namei.c:581 vfs_unlink+0x2fb/0x9b0 home/cc/linux/fs/namei.c:4544 do_unlinkat+0x4c5/0x6a0 home/cc/linux/fs/namei.c:4608 __do_sys_unlink home/cc/linux/fs/namei.c:4654 [inline] __se_sys_unlink home/cc/linux/fs/namei.c:4652 [inline] __x64_sys_unlink+0xc5/0x110 home/cc/linux/fs/namei.c:4652 do_syscall_x64 home/cc/linux/arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc7/0x250 home/cc/linux/arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb3d092324b Code: 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 57 00 00 00 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdc232d938 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb3d092324b RDX: 00007ffdc232d960 RSI: 00007ffdc232d960 RDI: 00007ffdc232d9f0 RBP: 00007ffdc232d9f0 R08: 0000000000000001 R09: 00007ffdc232d7c0 R10: 00000000fffffffd R11: 0000000000000206 R12: 00007ffdc232eaf0 R13: 000055555d0cebb0 R14: 00007ffdc232d958 R15: 0000000000000001 </task>

Cc: stable@vger.kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org --- fs/f2fs/namei.c | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index 8f8b9b843bdf..f17cb2489a73 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -569,6 +569,15 @@ static int f2fs_unlink(struct inode *dir, struct dentry *dentry) goto fail; }

+ if (unlikely(inode->i_nlink == 0)) { + f2fs_warn(F2FS_I_SB(inode), "%s: inode (ino=%lx) has zero i_nlink", + __func__, inode->i_ino); + err = -EFSCORRUPTED; + set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK); + f2fs_put_page(page, 0); + goto fail; + } + f2fs_balance_fs(sbi, true);

f2fs_lock_op(sbi);