general protection fault, probably for non-canonical address 0xdffffc00000000b2: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000590-0x0000000000000597] CPU: 1 PID: 6612 Comm: syz-executor.4 Not tainted 5.14.0-rc5-next-20210812-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: 0018:ffffc90000dc0cd8 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 00000000000000b2 RSI: ffffffff83d2005d RDI: 0000000000000590 RBP: ffff888145fc8800 R08: 0000000000000003 R09: ffff888145fc8983 R10: ffffffff83d20052 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000000 R14: ffff88801ad88d00 R15: ffff888145fc88d0 FS: 0000000002640400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000014a53ad CR3: 000000003db2f000 CR4: 00000000001526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 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+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:check_kcov_mode+0x7/0x40 kernel/kcov.c:163 Code: fe ff ff 48 89 df e8 b8 be 45 00 e9 a1 fe ff ff 48 8b 3c 24 e8 aa be 45 00 e9 18 fe ff ff cc cc cc cc cc 65 8b 05 b9 3e 8c 7e <89> c2 81 e2 00 01 00 00 a9 00 01 ff 00 74 10 31 c0 85 d2 74 15 8b RSP: 0018:ffffc90002d4fb60 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 1ffff1100321885b RSI: ffff88801b98b900 RDI: 0000000000000003 RBP: ffffc90002d4fd00 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8144001a R11: 0000000000000000 R12: 00000000026406d0 R13: 0000000000000000 R14: ffff8880190c3900 R15: 0000000001200000 write_comp_data kernel/kcov.c:218 [inline] __sanitizer_cov_trace_const_cmp4+0x1c/0x70 kernel/kcov.c:284 copy_process+0x117a/0x7510 kernel/fork.c:2033 kernel_clone+0xe7/0xac0 kernel/fork.c:2561 __do_sys_clone+0xc8/0x110 kernel/fork.c:2678 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x464bdb Code: ed 0f 85 60 01 00 00 64 4c 8b 0c 25 10 00 00 00 45 31 c0 4d 8d 91 d0 02 00 00 31 d2 31 f6 bf 11 00 20 01 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 89 00 00 00 41 89 c5 85 c0 0f 85 90 00 00 RSP: 002b:00007ffc89c0cd20 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000464bdb RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000002640400 R10: 00000000026406d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffc89c0ce10 Modules linked in: vkms_vblank_simulate: vblank timer overrun ---[ end trace 6e8e90b300f4b7d2 ]--- 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: 0018:ffffc90000dc0cd8 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000100 RDX: 00000000000000b2 RSI: ffffffff83d2005d RDI: 0000000000000590 RBP: ffff888145fc8800 R08: 0000000000000003 R09: ffff888145fc8983 R10: ffffffff83d20052 R11: 0000000000000000 R12: 0000000000000003 R13: 0000000000000000 R14: ffff88801ad88d00 R15: ffff888145fc88d0 FS: 0000000002640400(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000014a53ad CR3: 000000003db2f000 CR4: 00000000001526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600