loop3: 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: 0 PID: 7949 Comm: syz.3.935 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
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 df 34 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 b7 34 ec fd bb 90 00 00 00 49 03 1e
RSP: 0018:ffffc9000441f700 EFLAGS: 00010202
RAX: 00000000000000ba RBX: ffff888050651148 RCX: dffffc0000000000
RDX: ffffc9000dd69000 RSI: 0000000000021a06 RDI: 0000000000021a07
RBP: 1ffff1100a0ca231 R08: dffffc0000000000 R09: 1ffffffff203a418
R10: dffffc0000000000 R11: fffffbfff203a419 R12: ffff888079e96110
R13: ffff888050651188 R14: 00000000000005d0 R15: ffff888020c11dec
FS:  00007f43c66476c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000003f8030 CR3: 000000007a76a000 CR4: 00000000003506f0
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]
 lmGroupCommit+0x5b4/0xb70 fs/jfs/jfs_logmgr.c:695
 txCommit+0x4731/0x5200 fs/jfs/jfs_txnmgr.c:1305
 jfs_commit_inode+0x2ec/0x520 fs/jfs/inode.c:114
 jfs_fsync+0x181/0x1b0 fs/jfs/file.c:37
 generic_write_sync include/linux/fs.h:2990 [inline]
 generic_file_write_iter+0x157/0x1b0 mm/filemap.c:3948
 call_write_iter include/linux/fs.h:2173 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x745/0xd60 fs/read_write.c:594
 ksys_pwrite64 fs/read_write.c:701 [inline]
 __do_sys_pwrite64 fs/read_write.c:711 [inline]
 __se_sys_pwrite64 fs/read_write.c:708 [inline]
 __x64_sys_pwrite64+0x19a/0x220 fs/read_write.c:708
 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: 0033:0x7f43c83ebeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f43c6647028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f43c8666fa0 RCX: 00007f43c83ebeb9
RDX: 000000000000fdef RSI: 0000200000000140 RDI: 0000000000000004
RBP: 00007f43c8459c1f R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fecc R11: 0000000000000246 R12: 0000000000000000
R13: 00007f43c8667038 R14: 00007f43c8666fa0 R15: 00007ffd418a5208
 </TASK>
Modules linked in:
---[ end trace ba1604660053c4f8 ]---
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 df 34 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 b7 34 ec fd bb 90 00 00 00 49 03 1e
RSP: 0018:ffffc9000441f700 EFLAGS: 00010202
RAX: 00000000000000ba RBX: ffff888050651148 RCX: dffffc0000000000
RDX: ffffc9000dd69000 RSI: 0000000000021a06 RDI: 0000000000021a07
RBP: 1ffff1100a0ca231 R08: dffffc0000000000 R09: 1ffffffff203a418
R10: dffffc0000000000 R11: fffffbfff203a419 R12: ffff888079e96110
R13: ffff888050651188 R14: 00000000000005d0 R15: ffff888020c11dec
FS:  00007f43c66476c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2e201d4600 CR3: 000000007a76a000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	ff                   	lcall  (bad)
   1:	df 80 3c 08 00 74    	filds  0x7400083c(%rax)
   7:	08 48 89             	or     %cl,-0x77(%rax)
   a:	df e8                	fucomip %st(0),%st
   c:	df 34 ec             	fbstp  (%rsp,%rbp,8)
   f:	fd                   	std
  10:	41 be d0 05 00 00    	mov    $0x5d0,%r14d
  16:	4c 03 33             	add    (%rbx),%r14
  19:	4c 89 f0             	mov    %r14,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 f7             	mov    %r14,%rdi
  33:	e8 b7 34 ec fd       	call   0xfdec34ef
  38:	bb 90 00 00 00       	mov    $0x90,%ebx
  3d:	49 03 1e             	add    (%r14),%rbx