general protection fault, probably for non-canonical address 0xdffffc000000005b: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000002d8-0x00000000000002df] CPU: 0 PID: 17926 Comm: syz.6.7062 Not tainted 5.10.239-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:254 [inline] RIP: 0010:fib_lookup_good_nhc net/ipv4/fib_trie.c:1363 [inline] RIP: 0010:nexthop_get_nhc_lookup+0x1a2/0x6c0 include/net/nexthop.h:291 Code: 74 08 48 89 df e8 be 0e c1 fd 48 89 5d a8 48 8b 1b b8 d8 02 00 00 48 01 c3 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 90 0e c1 fd 48 8b 1b 48 85 db 74 68 RSP: 0000:ffffc90000007660 EFLAGS: 00010202 RAX: 000000000000005b RBX: 00000000000002d8 RCX: dffffc0000000000 RDX: ffff88812cfe4f00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900000076d0 R08: dffffc0000000000 R09: ffffc900000078c0 R10: fffff52000000f1e R11: 1ffff92000000f18 R12: ffff88810a756300 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8881276cd390 FS: 00007f091a5b36c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f303ff8 CR3: 000000014b2f4000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: fib_table_lookup+0xe4c/0x1730 net/ipv4/fib_trie.c:1542 fib_lookup include/net/ip_fib.h:379 [inline] ip_route_output_key_hash_rcu+0x477/0x2060 net/ipv4/route.c:2671 ip_route_output_key_hash net/ipv4/route.c:2561 [inline] __ip_route_output_key include/net/route.h:126 [inline] ip_route_output_flow+0x123/0x2d0 net/ipv4/route.c:2793 ip_route_output_key include/net/route.h:142 [inline] tipc_udp_xmit+0x1aa/0x8e0 net/tipc/udp_media.c:183 tipc_udp_send_msg+0x20c/0x2e0 net/tipc/udp_media.c:265 tipc_bearer_xmit_skb+0x27d/0x360 net/tipc/bearer.c:548 tipc_disc_timeout+0x6a2/0x830 net/tipc/discover.c:337 call_timer_fn+0x38/0x290 kernel/time/timer.c:1450 expire_timers kernel/time/timer.c:1495 [inline] __run_timers+0x639/0x9a0 kernel/time/timer.c:1789 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1802 __do_softirq+0x255/0x563 kernel/softirq.c:309 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x60/0x80 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:405 [inline] __irq_exit_rcu+0x128/0x150 kernel/softirq.c:435 irq_exit_rcu+0x9/0x10 kernel/softirq.c:447 sysvec_apic_timer_interrupt+0xbf/0xe0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x49/0x70 kernel/locking/spinlock.c:199 Code: 12 48 89 fb 48 c7 c7 f0 64 2c 86 e8 81 57 27 fd 48 89 df 48 83 3d 06 37 b6 01 00 74 27 e8 53 d8 d4 fc 66 90 fb bf 01 00 00 00 e2 d7 cd fc 65 8b 05 87 3f 8c 7b 85 c0 74 03 5b 5d c3 e8 c3 3c RSP: 0000:ffffc9000069f3e8 EFLAGS: 00000246 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: dffffc0000000000 RDX: 0000000000000001 RSI: ffffffff85200ea0 RDI: 0000000000000001 RBP: ffffc9000069f3f0 R08: dffffc0000000000 R09: ffffed10259fc4f1 R10: ffffed10259fc4f1 R11: 1ffff110259fc4f0 R12: ffff8881f7055fc0 R13: ffff88812cfe27ac R14: 0000000000000000 R15: ffff88812cfe4f00 finish_lock_switch kernel/sched/core.c:3786 [inline] finish_task_switch+0x12e/0x5a0 kernel/sched/core.c:3886 context_switch kernel/sched/core.c:4051 [inline] __schedule+0xb4f/0x1310 kernel/sched/core.c:4806 schedule+0x13c/0x1d0 kernel/sched/core.c:4884 schedule_timeout+0xa6/0x2d0 kernel/time/timer.c:1889 unix_wait_for_peer+0x1e5/0x2e0 net/unix/af_unix.c:1229 unix_dgram_sendmsg+0x1012/0x17d0 net/unix/af_unix.c:1818 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430 __sys_sendmmsg+0x273/0x450 net/socket.c:2516 __do_sys_sendmmsg net/socket.c:2545 [inline] __se_sys_sendmmsg net/socket.c:2542 [inline] __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2542 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f091bf4a929 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:00007f091a5b3038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f091c171fa0 RCX: 00007f091bf4a929 RDX: 0000000000000318 RSI: 00002000000bd000 RDI: 0000000000000004 RBP: 00007f091bfccb39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f091c171fa0 R15: 00007ffe496f99e8 Modules linked in: ---[ end trace 8a20f29a4d7593b5 ]--- RIP: 0010:ip_ignore_linkdown include/linux/inetdevice.h:254 [inline] RIP: 0010:fib_lookup_good_nhc net/ipv4/fib_trie.c:1363 [inline] RIP: 0010:nexthop_get_nhc_lookup+0x1a2/0x6c0 include/net/nexthop.h:291 Code: 74 08 48 89 df e8 be 0e c1 fd 48 89 5d a8 48 8b 1b b8 d8 02 00 00 48 01 c3 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 90 0e c1 fd 48 8b 1b 48 85 db 74 68 RSP: 0000:ffffc90000007660 EFLAGS: 00010202 RAX: 000000000000005b RBX: 00000000000002d8 RCX: dffffc0000000000 RDX: ffff88812cfe4f00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900000076d0 R08: dffffc0000000000 R09: ffffc900000078c0 R10: fffff52000000f1e R11: 1ffff92000000f18 R12: ffff88810a756300 R13: 0000000000000000 R14: 0000000000000000 R15: ffff8881276cd390 FS: 00007f091a5b36c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f303ff8 CR3: 000000014b2f4000 CR4: 00000000003506b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 74 08 je 0xa 2: 48 89 df mov %rbx,%rdi 5: e8 be 0e c1 fd call 0xfdc10ec8 a: 48 89 5d a8 mov %rbx,-0x58(%rbp) e: 48 8b 1b mov (%rbx),%rbx 11: b8 d8 02 00 00 mov $0x2d8,%eax 16: 48 01 c3 add %rax,%rbx 19: 48 89 d8 mov %rbx,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 48 89 df mov %rbx,%rdi 33: e8 90 0e c1 fd call 0xfdc10ec8 38: 48 8b 1b mov (%rbx),%rbx 3b: 48 85 db test %rbx,%rbx 3e: 74 68 je 0xa8