BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 1c731e067 P4D 1c731e067 PUD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 3181 Comm: syz.4.754 Not tainted 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: ffff8881e8986e40 RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881dfdc31c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffb120 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881dfdc31c0 FS: 00007f3d8ee416c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001e3904000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 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:last_frame arch/x86/kernel/unwind_frame.c:88 [inline] RIP: 0010:is_last_frame arch/x86/kernel/unwind_frame.c:93 [inline] RIP: 0010:is_last_task_frame arch/x86/kernel/unwind_frame.c:162 [inline] RIP: 0010:unwind_next_frame+0xf2/0x760 arch/x86/kernel/unwind_frame.c:272 Code: 00 49 b8 00 00 00 00 00 fc ff df 4c 89 6d b0 4c 89 7d a8 4c 89 75 c0 4c 8b 7b 38 4c 8d 73 28 4c 89 f0 48 c1 e8 03 48 89 45 90 <42> 80 3c 00 00 74 12 4c 89 f7 e8 6f dc 5f 00 49 b8 00 00 00 00 00 RSP: 0018:ffff8881dfe96ff8 EFLAGS: 00000a02 ORIG_RAX: ffffffffffffff13 RAX: 1ffff1103bfd2e16 RBX: ffff8881dfe97088 RCX: 0000000000000002 RDX: ffff8881e8986e40 RSI: 0000000000000040 RDI: ffff8881dfe97088 RBP: ffff8881dfe97078 R08: dffffc0000000000 R09: ffff8881dfe97088 R10: ffffed103bfd2e1d R11: 1ffff1103bfd2e11 R12: 0000000000000000 R13: 1ffff1103bfd2e1c R14: ffff8881dfe970b0 R15: ffff8881dfe97f10 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0xf0 kernel/stacktrace.c:123 save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:345 [inline] __kasan_slab_free+0x1c3/0x280 mm/kasan/common.c:487 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496 slab_free_hook mm/slub.c:1455 [inline] slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494 slab_free mm/slub.c:3080 [inline] kfree+0xbe/0x260 mm/slub.c:4071 skb_free_head net/core/skbuff.c:601 [inline] skb_release_data+0x4ea/0x610 net/core/skbuff.c:621 skb_release_all net/core/skbuff.c:675 [inline] __kfree_skb net/core/skbuff.c:689 [inline] consume_skb+0xad/0x240 net/core/skbuff.c:849 __pskb_pull_tail+0x723/0x13d0 net/core/skbuff.c:2208 __skb_linearize include/linux/skbuff.h:3339 [inline] skb_linearize include/linux/skbuff.h:3351 [inline] tipc_msg_reverse+0x7b/0x990 net/tipc/msg.c:569 tipc_sk_filter_rcv+0x9fb/0x22d0 net/tipc/socket.c:2227 tipc_sk_backlog_rcv+0x109/0x1f0 net/tipc/socket.c:2258 sk_backlog_rcv include/net/sock.h:984 [inline] __release_sock+0x146/0x360 net/core/sock.c:2470 release_sock+0x60/0x1b0 net/core/sock.c:3025 tipc_sendstream+0x5f/0x70 net/tipc/socket.c:1451 sock_sendmsg_nosec net/socket.c:638 [inline] __sock_sendmsg net/socket.c:650 [inline] ____sys_sendmsg+0x57b/0x8d0 net/socket.c:2306 ___sys_sendmsg net/socket.c:2360 [inline] __sys_sendmsg+0x28e/0x360 net/socket.c:2406 __do_sys_sendmsg net/socket.c:2415 [inline] __se_sys_sendmsg net/socket.c:2413 [inline] __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2413 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7f3d907d8969 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:00007f3d8ee41038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f3d909fffa0 RCX: 00007f3d907d8969 RDX: 0000000000000000 RSI: 0000200000000380 RDI: 0000000000000006 RBP: 00007f3d9085aab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3d909fffa0 R15: 00007ffced8d1118 Modules linked in: CR2: 0000000000000000 ---[ end trace 5071cf617679f9d2 ]--- RIP: 0010:0x0 Code: Bad RIP value. RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010206 RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881e8986e40 RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881dfdc31c0 RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003 R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffffb120 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881dfdc31c0 FS: 00007f3d8ee416c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001e3904000 CR4: 00000000003406b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 49 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%r8 7: fc ff df a: 4c 89 6d b0 mov %r13,-0x50(%rbp) e: 4c 89 7d a8 mov %r15,-0x58(%rbp) 12: 4c 89 75 c0 mov %r14,-0x40(%rbp) 16: 4c 8b 7b 38 mov 0x38(%rbx),%r15 1a: 4c 8d 73 28 lea 0x28(%rbx),%r14 1e: 4c 89 f0 mov %r14,%rax 21: 48 c1 e8 03 shr $0x3,%rax 25: 48 89 45 90 mov %rax,-0x70(%rbp) * 29: 42 80 3c 00 00 cmpb $0x0,(%rax,%r8,1) <-- trapping instruction 2e: 74 12 je 0x42 30: 4c 89 f7 mov %r14,%rdi 33: e8 6f dc 5f 00 call 0x5fdca7 38: 49 rex.WB 39: b8 00 00 00 00 mov $0x0,%eax