Oops: general protection fault, probably for non-canonical address 0xdffffc0000000011: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f] CPU: 0 UID: 0 PID: 5924 Comm: kworker/0:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: events gfs2_withdraw_func RIP: 0010:gfs2_log_is_empty+0x73/0xd0 fs/gfs2/log.c:430 Code: f0 09 00 00 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 1d 20 28 fe 41 be 8c 00 00 00 4c 03 33 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 34 41 8b 1e 89 ef 89 de e8 d8 6a c2 fd 39 RSP: 0018:ffffc9000453f8d8 EFLAGS: 00010207 RAX: 0000000000000011 RBX: ffff88807e9009f0 RCX: ffffffff83fe0da0 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807e900d70 RBP: 0000000000000000 R08: ffff88807e900d73 R09: 1ffff1100fd201ae R10: dffffc0000000000 R11: ffffed100fd201af R12: 1ffff920008a7f24 R13: 1ffff1100fd20000 R14: 000000000000008c R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125cfd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f02567d7000 CR3: 000000007fe06000 CR4: 00000000003526f0 Call Trace: do_withdraw+0x15f/0x320 fs/gfs2/util.c:139 gfs2_withdraw_func+0x2f3/0x430 fs/gfs2/util.c:-1 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:gfs2_log_is_empty+0x73/0xd0 fs/gfs2/log.c:430 Code: f0 09 00 00 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 1d 20 28 fe 41 be 8c 00 00 00 4c 03 33 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 38 84 c0 75 34 41 8b 1e 89 ef 89 de e8 d8 6a c2 fd 39 RSP: 0018:ffffc9000453f8d8 EFLAGS: 00010207 RAX: 0000000000000011 RBX: ffff88807e9009f0 RCX: ffffffff83fe0da0 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88807e900d70 RBP: 0000000000000000 R08: ffff88807e900d73 R09: 1ffff1100fd201ae R10: dffffc0000000000 R11: ffffed100fd201af R12: 1ffff920008a7f24 R13: 1ffff1100fd20000 R14: 000000000000008c R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125cfd000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f02567d7000 CR3: 000000007fe06000 CR4: 00000000003526f0 ---------------- Code disassembly (best guess): 0: f0 09 00 lock or %eax,(%rax) 3: 00 48 89 add %cl,-0x77(%rax) 6: d8 48 c1 fmuls -0x3f(%rax) 9: e8 03 42 80 3c call 0x3c804211 e: 38 00 cmp %al,(%rax) 10: 74 08 je 0x1a 12: 48 89 df mov %rbx,%rdi 15: e8 1d 20 28 fe call 0xfe282037 1a: 41 be 8c 00 00 00 mov $0x8c,%r14d 20: 4c 03 33 add (%rbx),%r14 23: 4c 89 f0 mov %r14,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 75 34 jne 0x67 33: 41 8b 1e mov (%r14),%ebx 36: 89 ef mov %ebp,%edi 38: 89 de mov %ebx,%esi 3a: e8 d8 6a c2 fd call 0xfdc26b17 3f: 39 .byte 0x39