loop0: detected capacity change from 0 to 32768
general protection fault, probably for non-canonical address 0xdffffc00000000ba: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000005d0-0x00000000000005d7]
CPU: 1 PID: 5891 Comm: syz.0.312 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:blkg_tryget_closest block/blk-cgroup.c:1846 [inline]
RIP: 0010:bio_associate_blkg_from_css+0x2ab/0x9c0 block/blk-cgroup.c:1880
Code: ff df 80 3c 08 00 74 08 48 89 df e8 3f 1a ec fd 41 be d0 05 00 00 4c 03 33 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 17 1a ec fd bb 90 00 00 00 49 03 1e
RSP: 0018:ffffc9000328f940 EFLAGS: 00010202
RAX: 00000000000000ba RBX: ffff88805e23bb48 RCX: dffffc0000000000
RDX: ffffc900040e2000 RSI: 0000000000001f5d RDI: 0000000000001f5e
RBP: 1ffff1100bc47771 R08: dffffc0000000000 R09: 1ffffffff203a818
R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffff88814d5c1110
R13: ffff88805e23bb88 R14: 00000000000005d0 R15: ffff888074611dec
FS:  00007ff47efc86c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff25477b000 CR3: 000000005fe94000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bio_associate_blkg+0x23a/0x340 block/blk-cgroup.c:1908
 lbmStartIO+0x204/0x4c0 fs/jfs/jfs_logmgr.c:2130
 lbmWrite+0x361/0x480 fs/jfs/jfs_logmgr.c:2079
 lmGCwrite fs/jfs/jfs_logmgr.c:-1 [inline]
 jfs_flush_journal+0x537/0xec0 fs/jfs/jfs_logmgr.c:1556
 jfs_sync_fs+0x79/0xa0 fs/jfs/super.c:689
 sync_filesystem+0xe6/0x220 fs/sync.c:56
 jfs_remount+0xee/0x5b0 fs/jfs/super.c:437
 reconfigure_super+0x219/0x8a0 fs/super.c:938
 do_remount fs/namespace.c:2697 [inline]
 path_mount+0xd54/0x1030 fs/namespace.c:3356
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff480d6fa8a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff47efc7e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff47efc7ee0 RCX: 00007ff480d6fa8a
RDX: 0000200000000f40 RSI: 0000200000000f00 RDI: 0000000000000000
RBP: 0000200000000f40 R08: 00007ff47efc7ee0 R09: 0000000001a4a438
R10: 0000000001a4a438 R11: 0000000000000246 R12: 0000200000000f00
R13: 00007ff47efc7ea0 R14: 0000000000000000 R15: 00002000000008c0
 </TASK>
Modules linked in:
---[ end trace a8d00b8e1606297a ]---
RIP: 0010:blkg_tryget_closest block/blk-cgroup.c:1846 [inline]
RIP: 0010:bio_associate_blkg_from_css+0x2ab/0x9c0 block/blk-cgroup.c:1880
Code: ff df 80 3c 08 00 74 08 48 89 df e8 3f 1a ec fd 41 be d0 05 00 00 4c 03 33 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 17 1a ec fd bb 90 00 00 00 49 03 1e
RSP: 0018:ffffc9000328f940 EFLAGS: 00010202
RAX: 00000000000000ba RBX: ffff88805e23bb48 RCX: dffffc0000000000
RDX: ffffc900040e2000 RSI: 0000000000001f5d RDI: 0000000000001f5e
RBP: 1ffff1100bc47771 R08: dffffc0000000000 R09: 1ffffffff203a818
R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffff88814d5c1110
R13: ffff88805e23bb88 R14: 00000000000005d0 R15: ffff888074611dec
FS:  00007ff47efc86c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f12a0c67700 CR3: 000000005fe94000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1)
   4:	74 08                	je     0xe
   6:	48 89 df             	mov    %rbx,%rdi
   9:	e8 3f 1a ec fd       	call   0xfdec1a4d
   e:	41 be d0 05 00 00    	mov    $0x5d0,%r14d
  14:	4c 03 33             	add    (%rbx),%r14
  17:	4c 89 f0             	mov    %r14,%rax
  1a:	48 c1 e8 03          	shr    $0x3,%rax
  1e:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  25:	fc ff df
* 28:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2c:	74 08                	je     0x36
  2e:	4c 89 f7             	mov    %r14,%rdi
  31:	e8 17 1a ec fd       	call   0xfdec1a4d
  36:	bb 90 00 00 00       	mov    $0x90,%ebx
  3b:	49 03 1e             	add    (%r14),%rbx