general protection fault, probably for non-canonical address 0xdffffc00000000b2: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000590-0x0000000000000597] CPU: 0 PID: 24162 Comm: syz-executor.4 Not tainted 5.14.0-rc6-next-20210817-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:latency_exceeded block/blk-wbt.c:237 [inline] RIP: 0010:wb_timer_fn+0x149/0x1740 block/blk-wbt.c:360 Code: 03 80 3c 02 00 0f 85 68 13 00 00 48 8b 9b c8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb 90 05 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 35 13 00 00 48 8b 9b 90 05 00 00 48 b8 00 00 00 RSP: 0000:ffffc900047afc20 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 00000000000000b2 RSI: ffffffff83d23d1d RDI: 0000000000000590 RBP: ffff88801d367800 R08: 0000000000000003 R09: ffff88801d367983 R10: ffffffff83d23d12 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000000 R14: ffff8880750ca680 R15: ffff88801d3678d0 FS: 0000000001f6d400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcc8184d78 CR3: 000000001d614000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0033:0x4193fb Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007ffd0752ba70 EFLAGS: 00000293 RAX: fffffffffffffff7 RBX: 0000000000000006 RCX: 00000000004193fb RDX: ffffffffffffffbc RSI: ffffffff8725c2e9 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000001b2f421340 R10: 00000000000012ad R11: 0000000000000293 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 00007ffd0752bb60 Modules linked in: ---[ end trace a4a5a581379d6313 ]--- RIP: 0010:latency_exceeded block/blk-wbt.c:237 [inline] RIP: 0010:wb_timer_fn+0x149/0x1740 block/blk-wbt.c:360 Code: 03 80 3c 02 00 0f 85 68 13 00 00 48 8b 9b c8 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d bb 90 05 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 35 13 00 00 48 8b 9b 90 05 00 00 48 b8 00 00 00 RSP: 0000:ffffc900047afc20 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 00000000000000b2 RSI: ffffffff83d23d1d RDI: 0000000000000590 RBP: ffff88801d367800 R08: 0000000000000003 R09: ffff88801d367983 R10: ffffffff83d23d12 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000000 R14: ffff8880750ca680 R15: ffff88801d3678d0 FS: 0000000001f6d400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcc8184d78 CR3: 000000001d614000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 03 80 3c 02 00 0f add 0xf00023c(%rax),%eax 6: 85 68 13 test %ebp,0x13(%rax) 9: 00 00 add %al,(%rax) b: 48 8b 9b c8 00 00 00 mov 0xc8(%rbx),%rbx 12: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 19: fc ff df 1c: 48 8d bb 90 05 00 00 lea 0x590(%rbx),%rdi 23: 48 89 fa mov %rdi,%rdx 26: 48 c1 ea 03 shr $0x3,%rdx 2a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction 2e: 0f 85 35 13 00 00 jne 0x1369 34: 48 8b 9b 90 05 00 00 mov 0x590(%rbx),%rbx 3b: 48 rex.W 3c: b8 .byte 0xb8 3d: 00 00 add %al,(%rax)