kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 1452 Comm: kmmpd-loop4 Not tainted 5.4.290-syzkaller-00002-g41adfeb3d639 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:bdevname+0x2c/0xb0 block/partition-generic.c:49
Code: 41 56 41 55 41 54 53 49 89 f6 48 89 fb 49 bd 00 00 00 00 00 fc ff df e8 d2 23 3e ff 48 8d bb 80 00 00 00 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 e8 0d 6e ff 4c 8b bb 80 00 00 00 48 83 c3
RSP: 0018:ffff8881d1a2fd70 EFLAGS: 00010202
RAX: 0000000000000010 RBX: 0000000000000000 RCX: ffff8881f30e0000
RDX: 0000000000000000 RSI: ffff8881c8658050 RDI: 0000000000000080
RBP: ffff8881d1a2ff00 R08: ffffffff81ccc168 R09: ffffed103eadf211
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1103cee207e
R13: dffffc0000000000 R14: ffff8881c8658050 R15: 000000000000000a
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32117ff8 CR3: 00000001e25e4000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 kmmpd+0x23b/0xa10 fs/ext4/mmp.c:158
 kthread+0x2da/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Modules linked in:
---[ end trace 8657cdf1db27cca7 ]---
RIP: 0010:bdevname+0x2c/0xb0 block/partition-generic.c:49
Code: 41 56 41 55 41 54 53 49 89 f6 48 89 fb 49 bd 00 00 00 00 00 fc ff df e8 d2 23 3e ff 48 8d bb 80 00 00 00 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 e8 0d 6e ff 4c 8b bb 80 00 00 00 48 83 c3
RSP: 0018:ffff8881d1a2fd70 EFLAGS: 00010202
RAX: 0000000000000010 RBX: 0000000000000000 RCX: ffff8881f30e0000
RDX: 0000000000000000 RSI: ffff8881c8658050 RDI: 0000000000000080
RBP: ffff8881d1a2ff00 R08: ffffffff81ccc168 R09: ffffed103eadf211
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff1103cee207e
R13: dffffc0000000000 R14: ffff8881c8658050 R15: 000000000000000a
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb385f21d58 CR3: 00000001dd991000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	41 56                	push   %r14
   2:	41 55                	push   %r13
   4:	41 54                	push   %r12
   6:	53                   	push   %rbx
   7:	49 89 f6             	mov    %rsi,%r14
   a:	48 89 fb             	mov    %rdi,%rbx
   d:	49 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%r13
  14:	fc ff df
  17:	e8 d2 23 3e ff       	call   0xff3e23ee
  1c:	48 8d bb 80 00 00 00 	lea    0x80(%rbx),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2f:	74 05                	je     0x36
  31:	e8 e8 0d 6e ff       	call   0xff6e0e1e
  36:	4c 8b bb 80 00 00 00 	mov    0x80(%rbx),%r15
  3d:	48                   	rex.W
  3e:	83                   	.byte 0x83
  3f:	c3                   	ret