bisecting fixing commit since 4fccc2503536a564a4ba31a1d50439854201659f building syzkaller on 2c36e7a75f8689b3da20e1a81a2ee5391f3af6e5 testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.4.1 20210217 kernel signature: e782d1d6cce5d35eb7d8fecff0afb4456eff90f991adeb94e74d92fac3d44be6 all runs: crashed: general protection fault in macvlan_hard_header testing current HEAD 255b58a2b3af0baa0ee11507390349217b8b73b0 testing commit 255b58a2b3af0baa0ee11507390349217b8b73b0 with gcc (GCC) 8.4.1 20210217 kernel signature: 521fd60a0cfb8a181725d524b69a518ad57e2a3c6c05c21e85fa46310c58b43b all runs: crashed: general protection fault in macvlan_hard_header revisions tested: 2, total time: 23m1.88292782s (build: 15m46.021272878s, test: 6m23.288416752s) the crash still happens on HEAD commit msg: Linux 4.19.176 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: 7417 Comm: syz-executor.1 Not tainted 4.19.176-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:2882 [inline] RIP: 0010:macvlan_hard_header+0x7e/0x190 drivers/net/macvlan.c:593 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:ffff8881f69077e8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffff895b3420 RCX: ffff8881d5f07cb8 RDX: 00000000000086dd RSI: 0007000460070004 RDI: ffffffff895b3640 RBP: ffff8881f6907828 R08: ffff8881e64c8090 R09: 0000000000000038 R10: 1ffff1103cf605b6 R11: 0000000000000000 R12: 0038002300380022 R13: ffff8881f3501280 R14: ffff8881f3501280 R15: ffff8881d5f07b40 FS: 00007f24696f3700(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000050d3d4 CR3: 00000001e2f7d006 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dev_hard_header include/linux/netdevice.h:2885 [inline] neigh_resolve_output net/core/neighbour.c:1369 [inline] neigh_resolve_output+0x46c/0x810 net/core/neighbour.c:1354 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0x8f6/0x2200 net/ipv6/ip6_output.c:120 ip6_finish_output+0x3c8/0xd20 net/ipv6/ip6_output.c:192 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x1bf/0x660 net/ipv6/ip6_output.c:209 dst_output include/net/dst.h:455 [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:3835 call_timer_fn+0x14c/0x510 kernel/time/timer.c:1338 expire_timers kernel/time/timer.c:1375 [inline] __run_timers kernel/time/timer.c:1696 [inline] __run_timers kernel/time/timer.c:1664 [inline] run_timer_softirq+0xb63/0x1180 kernel/time/timer.c:1709 __do_softirq+0x25f/0x919 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:535 [inline] smp_apic_timer_interrupt+0x13e/0x540 arch/x86/kernel/apic/apic.c:1098 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:console_unlock+0x904/0xde0 kernel/printk/printk.c:2468 Code: 00 fc ff df 48 89 f8 48 c1 e8 03 42 80 3c 18 00 0f 85 96 03 00 00 48 83 3d 60 9f 05 07 00 0f 84 08 02 00 00 48 8b 7d c8 57 9d <0f> 1f 44 00 00 e9 5d f8 ff ff 49 8d 7e 08 48 89 f8 48 c1 e8 03 42 RSP: 0018:ffff8881d62b69d8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff10a3f69 RBX: 0000000000000200 RCX: 1ffff11039ff99e2 RDX: 0000000000000000 RSI: ffff8881cffccef0 RDI: 0000000000000286 RBP: ffff8881d62b6a50 R08: ffff8881cffccf10 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff88c161a0 R15: ffffffff88c16170 vprintk_emit+0x191/0x540 kernel/printk/printk.c:1965 vprintk_default+0x1a/0x20 kernel/printk/printk.c:2007 vprintk_func+0x49/0x130 kernel/printk/printk_safe.c:397 printk+0x9a/0xc0 kernel/printk/printk.c:2040 addrconf_notify+0x1d69/0x1d90 net/ipv6/addrconf.c:3529 notifier_call_chain+0x8a/0x160 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 [inline] raw_notifier_call_chain+0x11/0x20 kernel/notifier.c:401 call_netdevice_notifiers_info+0x28/0x60 net/core/dev.c:1744 netdev_state_change net/core/dev.c:1349 [inline] netdev_state_change+0xd4/0x100 net/core/dev.c:1342 do_setlink+0x1b1a/0x2e10 net/core/rtnetlink.c:2661 rtnl_group_changelink net/core/rtnetlink.c:2925 [inline] rtnl_newlink+0xaff/0x1340 net/core/rtnetlink.c:3083 rtnetlink_rcv_msg+0x34f/0x8f0 net/core/rtnetlink.c:4778 netlink_rcv_skb+0x13e/0x3d0 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4796 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x443/0x650 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x764/0xc60 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xb5/0xf0 net/socket.c:632 ___sys_sendmsg+0x647/0x950 net/socket.c:2115 __sys_sendmsg+0xd9/0x180 net/socket.c:2153 __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2160 do_syscall_64+0xd0/0x4e0 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x463d89 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f24696f3198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000000009f9 RCX: 0000000000463d89 RDX: 0000000000000084 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 000000000000002e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000053bf00 R13: 00007f24696f36bc R14: 00000000ffffffff R15: 0000000000000003 Modules linked in: ---[ end trace 439a97b5196bc941 ]--- RIP: 0010:dev_hard_header include/linux/netdevice.h:2882 [inline] RIP: 0010:macvlan_hard_header+0x7e/0x190 drivers/net/macvlan.c:593 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:ffff8881f69077e8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffff895b3420 RCX: ffff8881d5f07cb8 RDX: 00000000000086dd RSI: 0007000460070004 RDI: ffffffff895b3640 RBP: ffff8881f6907828 R08: ffff8881e64c8090 R09: 0000000000000038 R10: 1ffff1103cf605b6 R11: 0000000000000000 R12: 0038002300380022 R13: ffff8881f3501280 R14: ffff8881f3501280 R15: ffff8881d5f07b40 FS: 00007f24696f3700(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000050d3d4 CR3: 00000001e2f7d006 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400