bisecting fixing commit since 4fccc2503536a564a4ba31a1d50439854201659f building syzkaller on 2c36e7a75f8689b3da20e1a81a2ee5391f3af6e5 testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.1.0 kernel signature: 0f763e4600a90dc45c64738a1561ec2fb7085e306c607f94efd984306d63b006 all runs: crashed: general protection fault in macvlan_hard_header testing current HEAD 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 testing commit 1bab61d3e8cd96f2badf515dcb06e4e1029bc017 with gcc (GCC) 8.1.0 kernel signature: ea908a7a15204f75391a3ab682f25be864c5ea976cd193585e6094f29f8070d3 all runs: crashed: general protection fault in macvlan_hard_header revisions tested: 2, total time: 24m42.960604406s (build: 17m35.104873997s, test: 6m33.594390091s) the crash still happens on HEAD commit msg: Linux 4.19.124 crash: general protection fault in macvlan_hard_header IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.124-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:dev_hard_header include/linux/netdevice.h:2890 [inline] RIP: 0010:macvlan_hard_header+0x7e/0x190 drivers/net/macvlan.c:589 Code: c1 ee 03 80 3c 06 00 0f 85 82 00 00 00 4c 8b a3 20 02 00 00 4d 85 e4 74 3a 48 b8 00 00 00 00 00 fc ff df 4c 89 e6 48 c1 ee 03 <80> 3c 06 00 0f 85 b3 00 00 00 49 8b 04 24 48 85 c0 74 16 48 89 de RSP: 0018:ffff8880aeb077c0 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffffffff895b03e0 RCX: ffff88809652e1b8 RDX: 00000000000086dd RSI: 0007200700000006 RDI: ffffffff895b0600 RBP: ffff8880aeb07800 R08: ffff88808c470a90 R09: 0000000000000038 R10: 1ffff11013e65666 R11: 0000000000000000 R12: 0039003800000037 R13: ffff88809a800a80 R14: ffff88809a800a80 R15: ffff88809652e040 FS: 0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3e7cd30 CR3: 000000008d7c0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dev_hard_header include/linux/netdevice.h:2893 [inline] neigh_resolve_output+0x46c/0x810 net/core/neighbour.c:1369 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0x90e/0x2310 net/ipv6/ip6_output.c:120 ip6_finish_output+0x3c4/0xa90 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x1bf/0x660 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:447 [inline] NF_HOOK include/linux/netfilter.h:289 [inline] ndisc_send_skb+0xcc8/0x12d0 net/ipv6/ndisc.c:491 ndisc_send_rs+0x116/0x5e0 net/ipv6/ndisc.c:685 addrconf_rs_timer+0x25c/0x5e0 net/ipv6/addrconf.c:3834 call_timer_fn+0x14c/0x510 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers kernel/time/timer.c:1684 [inline] run_timer_softirq+0xb63/0x1180 kernel/time/timer.c:1697 __do_softirq+0x260/0x92d kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:544 [inline] smp_apic_timer_interrupt+0x13e/0x540 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:native_safe_halt+0x12/0x20 arch/x86/include/asm/irqflags.h:61 Code: 11 ff ff ff 4c 89 e7 e8 4c 61 bb fa eb 97 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 e9 07 00 00 00 0f 00 2d a0 6a 51 00 fb f4 <5d> c3 66 90 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 e9 07 00 00 RSP: 0018:ffff8880a9837cf8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffff8880a981e3c0 RCX: 0000000000000000 RDX: 1ffffffff10a4044 RSI: 0000000000000001 RDI: ffffffff88520220 RBP: ffff8880a9837cf8 R08: ffffed1015d64733 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff88520210 R14: ffffffff89229258 R15: 0000000000000001 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0x51/0x310 arch/x86/kernel/process.c:565 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:556 default_idle_call+0x6d/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:153 [inline] do_idle+0x41e/0x560 kernel/sched/idle.c:263 cpu_startup_entry+0xc8/0xe0 kernel/sched/idle.c:369 start_secondary+0x403/0x5a0 arch/x86/kernel/smpboot.c:271 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 Modules linked in: ---[ end trace 1a54a5f5422b37f2 ]--- RIP: 0010:dev_hard_header include/linux/netdevice.h:2890 [inline] RIP: 0010:macvlan_hard_header+0x7e/0x190 drivers/net/macvlan.c:589 Code: c1 ee 03 80 3c 06 00 0f 85 82 00 00 00 4c 8b a3 20 02 00 00 4d 85 e4 74 3a 48 b8 00 00 00 00 00 fc ff df 4c 89 e6 48 c1 ee 03 <80> 3c 06 00 0f 85 b3 00 00 00 49 8b 04 24 48 85 c0 74 16 48 89 de RSP: 0018:ffff8880aeb077c0 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffffffff895b03e0 RCX: ffff88809652e1b8 RDX: 00000000000086dd RSI: 0007200700000006 RDI: ffffffff895b0600 RBP: ffff8880aeb07800 R08: ffff88808c470a90 R09: 0000000000000038 R10: 1ffff11013e65666 R11: 0000000000000000 R12: 0039003800000037 R13: ffff88809a800a80 R14: ffff88809a800a80 R15: ffff88809652e040 FS: 0000000000000000(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe1f3e7cd30 CR3: 000000008d7c0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400