Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 5359 Comm: syz.0.0 Not tainted 6.17.0-rc1-syzkaller-00014-g0e39a731820a #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:strcmp+0x3c/0xc0 lib/string.c:284
Code: 00 fc ff df 45 31 f6 4a 8d 04 37 48 89 c1 48 c1 e9 03 0f b6 0c 19 84 c9 75 2c 42 0f b6 2c 37 4a 8d 04 36 48 89 c1 48 c1 e9 03 <0f> b6 0c 19 84 c9 75 33 42 0f b6 0c 36 40 38 cd 75 48 49 ff c6 40
RSP: 0018:ffffc9000d46f8f8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 00000000433dee00 RSI: 0000000000000000 RDI: ffff8880433dee00
RBP: 0000000000000066 R08: ffff888043c01243 R09: 0000000000000000
R10: ffff888043c011d8 R11: ffffed1008780249 R12: 1ffff1100808a711
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880433dee00
FS:  00007f49bdf356c0(0000) GS:ffff88808d211000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49bdf34fc8 CR3: 000000004396b000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 f2fs_check_quota_consistency fs/f2fs/super.c:1188 [inline]
 f2fs_check_opt_consistency+0x1378/0x2c10 fs/f2fs/super.c:1436
 __f2fs_remount fs/f2fs/super.c:2653 [inline]
 f2fs_reconfigure+0x482/0x1770 fs/f2fs/super.c:5297
 reconfigure_super+0x224/0x890 fs/super.c:1077
 do_remount fs/namespace.c:3314 [inline]
 path_mount+0xd18/0xfe0 fs/namespace.c:4112
 do_mount fs/namespace.c:4133 [inline]
 __do_sys_mount fs/namespace.c:4344 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4321
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f49bd18ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f49bdf35038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f49bd3b6090 RCX: 00007f49bd18ebe9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000
RBP: 00007f49bd211e19 R08: 0000200000000140 R09: 0000000000000000
R10: 0000000000000020 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f49bd3b6128 R14: 00007f49bd3b6090 R15: 00007ffe3837c138
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:strcmp+0x3c/0xc0 lib/string.c:284
Code: 00 fc ff df 45 31 f6 4a 8d 04 37 48 89 c1 48 c1 e9 03 0f b6 0c 19 84 c9 75 2c 42 0f b6 2c 37 4a 8d 04 36 48 89 c1 48 c1 e9 03 <0f> b6 0c 19 84 c9 75 33 42 0f b6 0c 36 40 38 cd 75 48 49 ff c6 40
RSP: 0018:ffffc9000d46f8f8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 00000000433dee00 RSI: 0000000000000000 RDI: ffff8880433dee00
RBP: 0000000000000066 R08: ffff888043c01243 R09: 0000000000000000
R10: ffff888043c011d8 R11: ffffed1008780249 R12: 1ffff1100808a711
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880433dee00
FS:  00007f49bdf356c0(0000) GS:ffff88808d211000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f49bdf34fc8 CR3: 000000004396b000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess), 4 bytes skipped:
   0:	45 31 f6             	xor    %r14d,%r14d
   3:	4a 8d 04 37          	lea    (%rdi,%r14,1),%rax
   7:	48 89 c1             	mov    %rax,%rcx
   a:	48 c1 e9 03          	shr    $0x3,%rcx
   e:	0f b6 0c 19          	movzbl (%rcx,%rbx,1),%ecx
  12:	84 c9                	test   %cl,%cl
  14:	75 2c                	jne    0x42
  16:	42 0f b6 2c 37       	movzbl (%rdi,%r14,1),%ebp
  1b:	4a 8d 04 36          	lea    (%rsi,%r14,1),%rax
  1f:	48 89 c1             	mov    %rax,%rcx
  22:	48 c1 e9 03          	shr    $0x3,%rcx
* 26:	0f b6 0c 19          	movzbl (%rcx,%rbx,1),%ecx <-- trapping instruction
  2a:	84 c9                	test   %cl,%cl
  2c:	75 33                	jne    0x61
  2e:	42 0f b6 0c 36       	movzbl (%rsi,%r14,1),%ecx
  33:	40 38 cd             	cmp    %cl,%bpl
  36:	75 48                	jne    0x80
  38:	49 ff c6             	inc    %r14
  3b:	40                   	rex