BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1caeae067 P4D 1caeae067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 1 PID: 1578 Comm: syz.4.331 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: ffff8881e0772f40 RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881ebf071c0 RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffff9d98 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881ebf071c0 FS: 00007feaf46436c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001cad9f000 CR4: 00000000003406a0 DR0: ffffffffffffffff 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:check_memory_region+0x1a2/0x280 mm/kasan/generic.c:90 Code: d9 4d 89 d6 4d 8d 56 07 4d 85 f6 4d 0f 49 d6 49 83 e2 f8 4d 29 d6 74 12 41 80 39 00 0f 85 a1 00 00 00 49 ff c1 49 ff ce 75 ee <5b> 41 5e 41 5f 5d c3 84 db 75 61 f7 c3 00 ff 00 00 75 5e f7 c3 00 RSP: 0018:ffff8881c7a7f5a8 EFLAGS: 00000256 ORIG_RAX: ffffffffffffff13 RAX: ffffffff817c5001 RBX: 0000000000000000 RCX: ffffffff817c5018 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0007ad0740 RBP: ffff8881c7a7f5c0 R08: dffffc0000000000 R09: fffff94000f5a0e9 R10: fffff94000f5a0e9 R11: 1ffffd4000f5a0e8 R12: ffffea0007ad0740 R13: dffffc0000000000 R14: 0000000000000001 R15: dffffc0000000001 __kasan_check_read+0x11/0x20 mm/kasan/common.c:93 test_bit include/asm-generic/bitops-instrumented.h:237 [inline] PageReferenced include/linux/page-flags.h:315 [inline] mark_page_accessed+0x208/0x620 mm/swap.c:392 zap_pte_range mm/memory.c:1102 [inline] zap_pmd_range mm/memory.c:1222 [inline] zap_pud_range mm/memory.c:1251 [inline] zap_p4d_range mm/memory.c:1272 [inline] unmap_page_range+0x105b/0x1b20 mm/memory.c:1293 unmap_single_vma mm/memory.c:1338 [inline] unmap_vmas+0x245/0x340 mm/memory.c:1370 exit_mmap+0x2bb/0x520 mm/mmap.c:3191 __mmput+0x92/0x2e0 kernel/fork.c:1101 mmput+0x47/0x60 kernel/fork.c:1122 exit_mm kernel/exit.c:538 [inline] do_exit+0x99f/0x2660 kernel/exit.c:848 do_group_exit+0x13e/0x300 kernel/exit.c:984 get_signal+0xdee/0x13d0 kernel/signal.c:2738 do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159 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: 0033:0x7feaf5fda969 Code: Bad RIP value. RSP: 002b:00007feaf46430e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007feaf6201fa8 RCX: 00007feaf5fda969 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007feaf6201fa8 RBP: 00007feaf6201fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007feaf6201fac R13: 0000000000000000 R14: 00007ffea06626b0 R15: 00007ffea0662798 Modules linked in: CR2: 0000000000000000 ---[ end trace 1ce1f8cd68f57895 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881e0772f40 RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881ebf071c0 RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffff9d98 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881ebf071c0 FS: 00007feaf46436c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001cad9f000 CR4: 00000000003406a0 DR0: ffffffffffffffff DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 4d 89 d6 mov %r10,%r14 3: 4d 8d 56 07 lea 0x7(%r14),%r10 7: 4d 85 f6 test %r14,%r14 a: 4d 0f 49 d6 cmovns %r14,%r10 e: 49 83 e2 f8 and $0xfffffffffffffff8,%r10 12: 4d 29 d6 sub %r10,%r14 15: 74 12 je 0x29 17: 41 80 39 00 cmpb $0x0,(%r9) 1b: 0f 85 a1 00 00 00 jne 0xc2 21: 49 ff c1 inc %r9 24: 49 ff ce dec %r14 27: 75 ee jne 0x17 * 29: 5b pop %rbx <-- trapping instruction 2a: 41 5e pop %r14 2c: 41 5f pop %r15 2e: 5d pop %rbp 2f: c3 ret 30: 84 db test %bl,%bl 32: 75 61 jne 0x95 34: f7 c3 00 ff 00 00 test $0xff00,%ebx 3a: 75 5e jne 0x9a 3c: f7 .byte 0xf7 3d: c3 ret