BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1d7c41067 P4D 1d7c41067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 10665 Comm: syz.6.2856 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: 00010206 RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881f30c0fc0 RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881b046b1c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000fffff7d8 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881b046b1c0 FS: 00007eff43b836c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001e68b0000 CR4: 00000000003406b0 DR0: 0000000000000000 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:__read_once_size include/linux/compiler.h:268 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:155 [inline] RIP: 0010:write_comp_data kernel/kcov.c:208 [inline] RIP: 0010:__sanitizer_cov_trace_cmp4+0x21/0x80 kernel/kcov.c:248 Code: 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 48 8b 45 08 65 48 8b 15 40 0d a3 7e 65 8b 0d 45 0d a3 7e f7 c1 00 01 1f 00 74 02 5d c3 <8b> 8a 00 0a 00 00 83 f9 03 75 f3 48 8b 8a 08 0a 00 00 44 8b 8a 04 RSP: 0018:ffff8881e1dae4f8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffffff814fbc64 RBX: 0000000000000010 RCX: 0000000080000000 RDX: ffff8881f30c0fc0 RSI: 0000000000000010 RDI: 000000000000000d RBP: ffff8881e1dae4f8 R08: dffffc0000000000 R09: ffff8881e1dae568 R10: ffffed103c3b5cb9 R11: 1ffff1103c3b5cad R12: ffff8881e1dae620 R13: 1ffff1103c3b5cc6 R14: dffffc0000000000 R15: 000000000000000d stack_trace_consume_entry+0x74/0x250 kernel/stacktrace.c:86 arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0xaa/0xf0 kernel/stacktrace.c:123 save_stack+0x97/0x560 mm/page_owner.c:122 __set_page_owner+0x39/0x1e0 mm/page_owner.c:191 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook mm/page_alloc.c:2165 [inline] prep_new_page+0x35e/0x370 mm/page_alloc.c:2171 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894 __alloc_pages include/linux/gfp.h:503 [inline] __alloc_pages_node include/linux/gfp.h:516 [inline] alloc_pages_node include/linux/gfp.h:530 [inline] shmem_alloc_page mm/shmem.c:1503 [inline] shmem_alloc_and_acct_page+0x40b/0x820 mm/shmem.c:1528 shmem_getpage_gfp+0xe89/0x2370 mm/shmem.c:1852 shmem_getpage mm/shmem.c:154 [inline] shmem_write_begin+0xce/0x1b0 mm/shmem.c:2447 generic_perform_write+0x2b8/0x500 mm/filemap.c:3450 __generic_file_write_iter+0x24b/0x480 mm/filemap.c:3579 generic_file_write_iter+0x48d/0x620 mm/filemap.c:3611 call_write_iter include/linux/fs.h:1991 [inline] new_sync_write fs/read_write.c:483 [inline] __vfs_write+0x480/0x5d0 fs/read_write.c:496 __kernel_write+0xea/0x320 fs/read_write.c:515 dump_emit+0x1c0/0x2c0 fs/coredump.c:838 elf_core_dump+0x3465/0x3bd0 fs/binfmt_elf.c:2352 do_coredump+0x1d8c/0x2ab0 fs/coredump.c:801 get_signal+0xdb7/0x13d0 kernel/signal.c:2732 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 ret_from_intr+0x1c/0x1c RIP: 0033:0x7eff4551a971 Code: 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 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:00002000000000a0 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007eff45741fa0 RCX: 00007eff4551a969 RDX: 00002000000000c0 RSI: 00002000000000a0 RDI: 0000000000242000 RBP: 00007eff4559cab1 R08: 0000200000000200 R09: 0000200000000200 R10: 00002000000001c0 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000001 R14: 00007eff45741fa0 R15: 00007ffcc606fc28 Modules linked in: CR2: 0000000000000000 ---[ end trace 5aad8c2728a036f7 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206 RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881f30c0fc0 RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881b046b1c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000fffff7d8 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881b046b1c0 FS: 00007eff43b836c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001e68b0000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess): 0: 2e 0f 1f 84 00 00 00 cs nopl 0x0(%rax,%rax,1) 7: 00 00 9: 55 push %rbp a: 48 89 e5 mov %rsp,%rbp d: 48 8b 45 08 mov 0x8(%rbp),%rax 11: 65 48 8b 15 40 0d a3 mov %gs:0x7ea30d40(%rip),%rdx # 0x7ea30d59 18: 7e 19: 65 8b 0d 45 0d a3 7e mov %gs:0x7ea30d45(%rip),%ecx # 0x7ea30d65 20: f7 c1 00 01 1f 00 test $0x1f0100,%ecx 26: 74 02 je 0x2a 28: 5d pop %rbp 29: c3 ret * 2a: 8b 8a 00 0a 00 00 mov 0xa00(%rdx),%ecx <-- trapping instruction 30: 83 f9 03 cmp $0x3,%ecx 33: 75 f3 jne 0x28 35: 48 8b 8a 08 0a 00 00 mov 0xa08(%rdx),%rcx 3c: 44 rex.R 3d: 8b .byte 0x8b 3e: 8a .byte 0x8a 3f: 04 .byte 0x4