syzbot

F2FS-fs (loop0): Invalid blocksize (65536), supports only 4KB
F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (loop0): invalid crc value
F2FS-fs (loop0): Mounted with checkpoint version = 3e17dab0
================================================
WARNING: lock held when returning to user space!
4.14.296-syzkaller #0 Not tainted
------------------------------------------------
syz-executor198/7982 is leaving the kernel with locks still held!
1 lock held by syz-executor198/7982:
 #0:  (sb_writers#10){.+.+}, at: [<ffffffff818e0d3d>] sb_start_write include/linux/fs.h:1551 [inline]
 #0:  (sb_writers#10){.+.+}, at: [<ffffffff818e0d3d>] mnt_want_write_file+0xfd/0x3b0 fs/namespace.c:497
------------[ cut here ]------------
WARNING: CPU: 0 PID: 7982 at fs/namespace.c:1178 cleanup_mnt+0x222/0x2c0 fs/namespace.c:1178
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 7982 Comm: syz-executor198 Not tainted 4.14.296-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 panic+0x1f9/0x42d kernel/panic.c:183
 __warn.cold+0x20/0x44 kernel/panic.c:547
 report_bug+0x208/0x250 lib/bug.c:183
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:cleanup_mnt+0x222/0x2c0 fs/namespace.c:1178
RSP: 0018:ffff8880b4b17d08 EFLAGS: 00010297
RAX: ffff8880b335a380 RBX: dffffc0000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8a0932e0
RBP: 0000000000000008 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: ffff8880b335a380 R12: ffff8880b3a2ea00
R13: 0000000000000001 R14: 0000000000000007 R15: fffffbfff1412696
 task_work_run+0x11f/0x190 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0xa44/0x2850 kernel/exit.c:868
 do_group_exit+0x100/0x2e0 kernel/exit.c:965
 SYSC_exit_group kernel/exit.c:976 [inline]
 SyS_exit_group+0x19/0x20 kernel/exit.c:974
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f3d90052c89
RSP: 002b:00007fff68583ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f3d900c9330 RCX: 00007f3d90052c89
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffffffffffffffc0 R09: 00007f3d900c3e40
R10: 00007f3d900c3e40 R11: 0000000000000246 R12: 00007f3d900c9330
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
Kernel Offset: disabled
Rebooting in 86400 seconds..