BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1e531c067 P4D 1e531c067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 1 PID: 2911 Comm: syz.2.671 Tainted: G W 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f30f4ec0 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881dd1271c0 RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffbe00 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881dd1271c0 FS: 00007f326986c6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001e4068000 CR4: 00000000003406a0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448 expire_timers kernel/time/timer.c:1493 [inline] __run_timers+0x81d/0xb60 kernel/time/timer.c:1817 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830 __do_softirq+0x236/0x660 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x197/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:539 [inline] smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834 RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:135 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:165 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:181 [inline] RIP: 0010:check_memory_region+0x47/0x280 mm/kasan/generic.c:191 Code: f8 ff ff 01 00 0f 82 44 02 00 00 49 bf 01 00 00 00 00 fc ff df 49 89 fb 49 c1 eb 03 49 b8 00 00 00 00 00 fc ff df 4f 8d 0c 03 <48> 8d 5c 37 ff 48 c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce 49 83 fe RSP: 0018:ffff8881dc97fae8 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff13 RAX: ffff8881eab79f01 RBX: ffff8881eab79f80 RCX: ffffffff8147eff9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8881f30f4ec0 RBP: ffff8881dc97fb00 R08: dffffc0000000000 R09: ffffed103e61e9d8 R10: fffffbfff0c335b9 R11: 1ffff1103e61e9d8 R12: ffffffff8619add0 R13: ffffffff8619adc0 R14: ffff8881f30f4ec0 R15: dffffc0000000001 __kasan_check_read+0x11/0x20 mm/kasan/common.c:93 test_bit include/asm-generic/bitops-instrumented.h:237 [inline] test_ti_thread_flag include/linux/thread_info.h:97 [inline] need_resched include/linux/sched.h:1847 [inline] mutex_spin_on_owner+0x119/0x2e0 kernel/locking/mutex.c:580 mutex_optimistic_spin kernel/locking/mutex.c:685 [inline] __mutex_lock_common kernel/locking/mutex.c:973 [inline] __mutex_lock+0x2aa/0xe30 kernel/locking/mutex.c:1114 __mutex_lock_slowpath+0xe/0x10 kernel/locking/mutex.c:1375 mutex_lock+0xcf/0xe0 kernel/locking/mutex.c:296 rtnl_lock+0x15/0x20 net/core/rtnetlink.c:72 tun_detach drivers/net/tun.c:760 [inline] tun_chr_close+0x40/0x140 drivers/net/tun.c:3563 __fput+0x2a3/0x730 fs/file_table.c:281 ____fput+0x15/0x20 fs/file_table.c:314 task_work_run+0x146/0x170 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x195/0x1b0 arch/x86/entry/common.c:163 prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194 syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x13e/0x170 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f326b203969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f326986c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007f326b42afa0 RCX: 00007f326b203969 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f326b285ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f326b42afa0 R15: 00007ffff2c6ea38 Modules linked in: CR2: 0000000000000000 ---[ end trace f40602800b4e6c2b ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f30f4ec0 RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881dd1271c0 RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffbe00 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881dd1271c0 FS: 00007f326986c6c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001e4068000 CR4: 00000000003406a0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess), 3 bytes skipped: 0: 01 00 add %eax,(%rax) 2: 0f 82 44 02 00 00 jb 0x24c 8: 49 bf 01 00 00 00 00 movabs $0xdffffc0000000001,%r15 f: fc ff df 12: 49 89 fb mov %rdi,%r11 15: 49 c1 eb 03 shr $0x3,%r11 19: 49 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%r8 20: fc ff df 23: 4f 8d 0c 03 lea (%r11,%r8,1),%r9 * 27: 48 8d 5c 37 ff lea -0x1(%rdi,%rsi,1),%rbx <-- trapping instruction 2c: 48 c1 eb 03 shr $0x3,%rbx 30: 4e 8d 14 3b lea (%rbx,%r15,1),%r10 34: 4d 89 d6 mov %r10,%r14 37: 4d 29 ce sub %r9,%r14 3a: 49 rex.WB 3b: 83 .byte 0x83 3c: fe .byte 0xfe