general protection fault, probably for non-canonical address 0xdffffc00000000bb: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000005d8-0x00000000000005df] CPU: 1 PID: 19417 Comm: syz.1.2625 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 8f 09 ec fd 41 be d8 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 67 09 ec fd bb 90 00 00 00 49 03 1e RSP: 0018:ffffc90002eef940 EFLAGS: 00010206 RAX: 00000000000000bb RBX: ffff888076cae8c8 RCX: dffffc0000000000 RDX: ffffc900120e6000 RSI: 0000000000002c5b RDI: 0000000000002c5c RBP: 1ffff1100ed95d21 R08: dffffc0000000000 R09: 1ffffffff203b018 R10: dffffc0000000000 R11: fffffbfff203b019 R12: ffff88802b80c110 R13: ffff888076cae908 R14: 00000000000005d8 R15: ffff88802392002c FS: 00007fe24f62f6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe23a020000 CR3: 000000007e717000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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: 0033:0x7fe2513d70ca 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:00007fe24f62ee58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fe24f62eee0 RCX: 00007fe2513d70ca RDX: 0000200000000f40 RSI: 0000200000000f00 RDI: 0000000000000000 RBP: 0000200000000f40 R08: 00007fe24f62eee0 R09: 0000000001a5a438 R10: 0000000001a5a438 R11: 0000000000000246 R12: 0000200000000f00 R13: 00007fe24f62eea0 R14: 0000000000000000 R15: 00002000000032c0 Modules linked in: ---[ end trace 5e9d693afd9ee35b ]--- 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 8f 09 ec fd 41 be d8 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 67 09 ec fd bb 90 00 00 00 49 03 1e RSP: 0018:ffffc90002eef940 EFLAGS: 00010206 RAX: 00000000000000bb RBX: ffff888076cae8c8 RCX: dffffc0000000000 RDX: ffffc900120e6000 RSI: 0000000000002c5b RDI: 0000000000002c5c RBP: 1ffff1100ed95d21 R08: dffffc0000000000 R09: 1ffffffff203b018 R10: dffffc0000000000 R11: fffffbfff203b019 R12: ffff88802b80c110 R13: ffff888076cae908 R14: 00000000000005d8 R15: ffff88802392002c FS: 00007fe24f62f6c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555566da1a38 CR3: 000000007e717000 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 8f 09 ec fd call 0xfdec099d e: 41 be d8 05 00 00 mov $0x5d8,%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 67 09 ec fd call 0xfdec099d 36: bb 90 00 00 00 mov $0x90,%ebx 3b: 49 03 1e add (%r14),%rbx