BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 0 P4D 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 2698 Comm: syz.3.605 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:ffff8881f6e09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f5e1af40 RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881d7b631c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffac10 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d7b631c0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000005c0e000 CR4: 00000000003406b0 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:arch_atomic_add_negative arch/x86/include/asm/atomic.h:154 [inline] RIP: 0010:atomic_add_negative include/asm-generic/atomic-instrumented.h:768 [inline] RIP: 0010:page_remove_file_rmap mm/rmap.c:1252 [inline] RIP: 0010:page_remove_rmap+0x1f0/0x800 mm/rmap.c:1317 Code: 84 0f 04 00 00 e8 20 7e d7 ff 49 83 c5 40 eb bd e8 15 7e d7 ff 48 8d 7b 30 be 04 00 00 00 e8 57 52 05 00 31 f6 f0 83 43 30 ff <41> 0f 98 c6 40 0f 98 c6 bf 02 00 00 00 e8 3e 80 d7 ff 45 84 f6 0f RSP: 0018:ffff8881d626f5f8 EFLAGS: 00000213 ORIG_RAX: ffffffffffffff13 RAX: ffffffff81880001 RBX: ffffea000761e340 RCX: ffffffff818800d9 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffea000761e370 RBP: ffff8881d626f630 R08: dffffc0000000000 R09: fffff94000ec3c6f R10: fffff94000ec3c6f R11: 1ffffd4000ec3c6e R12: ffffea000761e358 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 zap_pte_range mm/memory.c:1105 [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+0xe8f/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+0x61/0x80 arch/x86/entry/common.c:274 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:346 RIP: 0033:0x7fe327e061c9 Code: Bad RIP value. RSP: 002b:00007fe3263d71c0 EFLAGS: 00000202 ORIG_RAX: 00000000000001b3 RAX: 0000000000000000 RBX: 00007fe327d885b0 RCX: 00007fe327e061c9 RDX: 00007fe327d885b0 RSI: 0000000000000058 RDI: 00007ffda3eddf20 RBP: 00007fe3263d76c0 R08: 00007fe3263d76c0 R09: 00007ffda3ede007 R10: 0000000000000008 R11: 0000000000000202 R12: ffffffffffffffa8 R13: 000000000000000b R14: 00007ffda3eddf20 R15: 00007ffda3ede008 Modules linked in: CR2: 0000000000000000 ---[ end trace 5736f52cfd5ac186 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010202 RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f5e1af40 RDX: 0000000080000101 RSI: 0000000000000000 RDI: ffff8881d7b631c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffac10 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d7b631c0 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000005c0e000 CR4: 00000000003406b0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess), 3 bytes skipped: 0: 00 00 add %al,(%rax) 2: e8 20 7e d7 ff call 0xffd77e27 7: 49 83 c5 40 add $0x40,%r13 b: eb bd jmp 0xffffffca d: e8 15 7e d7 ff call 0xffd77e27 12: 48 8d 7b 30 lea 0x30(%rbx),%rdi 16: be 04 00 00 00 mov $0x4,%esi 1b: e8 57 52 05 00 call 0x55277 20: 31 f6 xor %esi,%esi 22: f0 83 43 30 ff lock addl $0xffffffff,0x30(%rbx) * 27: 41 0f 98 c6 sets %r14b <-- trapping instruction 2b: 40 0f 98 c6 sets %sil 2f: bf 02 00 00 00 mov $0x2,%edi 34: e8 3e 80 d7 ff call 0xffd78077 39: 45 84 f6 test %r14b,%r14b 3c: 0f .byte 0xf