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: 4461 Comm: syz.4.75 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 4f 1f 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 27 1f ec fd bb 90 00 00 00 49 03 1e RSP: 0018:ffffc900034df7b0 EFLAGS: 00010202 RAX: 00000000000000ba RBX: ffff88805cc59508 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8a7a06e0 RDI: ffffffff8a7a06a0 RBP: 1ffff1100b98b2a9 R08: dffffc0000000000 R09: 1ffffffff203ac18 R10: dffffc0000000000 R11: fffffbfff203ac19 R12: ffff8881467c1110 R13: ffff88805cc59548 R14: 00000000000005d0 R15: ffff88801e25802c FS: 000055558dd40500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff3bdf5000 CR3: 000000007b4e3000 CR4: 00000000003506f0 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 lmNextPage+0x386/0xa00 fs/jfs/jfs_logmgr.c:-1 lmWriteRecord+0xf9d/0x1aa0 fs/jfs/jfs_logmgr.c:537 lmLog+0x6f6/0xa30 fs/jfs/jfs_logmgr.c:314 logMOUNT fs/jfs/jfs_mount.c:495 [inline] jfs_mount_rw+0x3e6/0x5c0 fs/jfs/jfs_mount.c:268 jfs_fill_super+0x5c1/0xb00 fs/jfs/super.c:570 mount_bdev+0x287/0x3c0 fs/super.c:1400 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x24a/0xa40 fs/namespace.c:3034 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: 0033:0x7f637628c0ca 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:00007fff3bdf44f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fff3bdf4580 RCX: 00007f637628c0ca RDX: 0000200000000000 RSI: 0000200000000100 RDI: 00007fff3bdf4540 RBP: 0000200000000000 R08: 00007fff3bdf4580 R09: 0000000001000002 R10: 0000000001000002 R11: 0000000000000246 R12: 0000200000000100 R13: 00007fff3bdf4540 R14: 000000000000615f R15: 00002000000063c0 Modules linked in: ---[ end trace 3fbfafdb08f15e21 ]--- 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 4f 1f 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 27 1f ec fd bb 90 00 00 00 49 03 1e RSP: 0018:ffffc900034df7b0 EFLAGS: 00010202 RAX: 00000000000000ba RBX: ffff88805cc59508 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8a7a06e0 RDI: ffffffff8a7a06a0 RBP: 1ffff1100b98b2a9 R08: dffffc0000000000 R09: 1ffffffff203ac18 R10: dffffc0000000000 R11: fffffbfff203ac19 R12: ffff8881467c1110 R13: ffff88805cc59548 R14: 00000000000005d0 R15: ffff88801e25802c FS: 000055558dd40500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdb5395f000 CR3: 000000007b4e3000 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: 4f 1f rex.WRXB (bad) e: ec in (%dx),%al 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 27 1f ec fd call 0xfdec1f5f 38: bb 90 00 00 00 mov $0x90,%ebx 3d: 49 03 1e add (%r14),%rbx