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: 4186 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:blkg_tryget_closest block/blk-cgroup.c:1842 [inline] RIP: 0010:bio_associate_blkg_from_css+0x2ab/0x9c0 block/blk-cgroup.c:1876 Code: ff df 80 3c 08 00 74 08 48 89 df e8 4f 36 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 36 ec fd bb 90 00 00 00 49 03 1e RSP: 0018:ffffc90002eff920 EFLAGS: 00010202 RAX: 00000000000000ba RBX: ffff88807f0d0148 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8a79f760 RDI: ffffffff8a79f720 RBP: 1ffff1100fe1a031 R08: dffffc0000000000 R09: 1ffffffff203a218 R10: dffffc0000000000 R11: fffffbfff203a219 R12: ffff888148879110 R13: ffff88807f0d0188 R14: 00000000000005d0 R15: ffff8880796c596c FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c26636f CR3: 000000006314b000 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:1904 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_umount+0xf8/0x360 fs/jfs/jfs_umount.c:58 jfs_put_super+0x88/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x130/0x300 fs/super.c:475 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x42d/0x4e0 fs/namespace.c:1148 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x626/0x20c0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 __do_sys_exit_group kernel/exit.c:1008 [inline] __se_sys_exit_group kernel/exit.c:1006 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006 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: 0033:0x7fba058f1eb9 Code: Unable to access opcode bytes at RIP 0x7fba058f1e8f. RSP: 002b:00007ffde36e1a28 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fba0595b773 RCX: 00007fba058f1eb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 0000000000000002 R08: 0000000000000000 R09: 00007fba0595b71f R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffde36e2ce0 R13: 00007fba0595b71f R14: 0000555564c7a4e8 R15: 00007ffde36e3db0 Modules linked in: ---[ end trace d3214c1e018f94b9 ]--- RIP: 0010:blkg_tryget_closest block/blk-cgroup.c:1842 [inline] RIP: 0010:bio_associate_blkg_from_css+0x2ab/0x9c0 block/blk-cgroup.c:1876 Code: ff df 80 3c 08 00 74 08 48 89 df e8 4f 36 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 36 ec fd bb 90 00 00 00 49 03 1e RSP: 0018:ffffc90002eff920 EFLAGS: 00010202 RAX: 00000000000000ba RBX: ffff88807f0d0148 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: ffffffff8a79f760 RDI: ffffffff8a79f720 RBP: 1ffff1100fe1a031 R08: dffffc0000000000 R09: 1ffffffff203a218 R10: dffffc0000000000 R11: fffffbfff203a219 R12: ffff888148879110 R13: ffff88807f0d0188 R14: 00000000000005d0 R15: ffff8880796c596c FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f08d4654000 CR3: 000000007d916000 CR4: 00000000003506e0 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 rex.WRXB d: 36 ec ss 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 36 ec fd call 0xfdec365f 38: bb 90 00 00 00 mov $0x90,%ebx 3d: 49 03 1e add (%r14),%rbx