bisecting fixing commit since 4fccc2503536a564a4ba31a1d50439854201659f building syzkaller on 2c36e7a75f8689b3da20e1a81a2ee5391f3af6e5 testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.1.0 kernel signature: 7e2a4058f3043ff7d3e3aa189bc1cc5db4760bd97734188c9b6246e69975eaec all runs: crashed: general protection fault in macvlan_hard_header testing current HEAD c110fed0e606ff922d5cad8ab74ba9410ca41694 testing commit c110fed0e606ff922d5cad8ab74ba9410ca41694 with gcc (GCC) 8.1.0 kernel signature: 15893fe12e5fd32f502dc0258fd3c9e1bb1de4af5364ed137d8e223ea4e6f0d6 all runs: crashed: general protection fault in macvlan_hard_header revisions tested: 2, total time: 22m54.801719999s (build: 16m46.281964439s, test: 5m41.433274399s) the crash still happens on HEAD commit msg: Linux 4.19.168 crash: general protection fault in macvlan_hard_header team0: Device macvtap0 is up. Set it down before adding it as a team port netlink: 8 bytes leftover after parsing attributes in process `syz-executor.3'. IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: 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: 7375 Comm: syz-executor.3 Not tainted 4.19.168-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:ffff8881f69077e0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffff895b23e0 RCX: ffff8881f3f7ef38 RDX: 00000000000086dd RSI: 0007000460070004 RDI: ffffffff895b2600 RBP: ffff8881f6907820 R08: ffff8881edeada90 R09: 0000000000000038 R10: 1ffff1103a089e1e R11: 0000000000000000 R12: 0038002300380022 R13: ffff8881cf566200 R14: ffff8881cf566200 R15: ffff8881f3f7edc0 FS: 00007f43e75c5700(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000071e434 CR3: 00000001cf41b004 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+0x46c/0x810 net/core/neighbour.c:1369 neigh_output include/net/neighbour.h:501 [inline] ip6_finish_output2+0x8f6/0x2200 net/ipv6/ip6_output.c:120 ip6_finish_output+0x3c6/0xa90 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: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:3834 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_timer_softirq+0xb63/0x1180 kernel/time/timer.c:1709 __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:545 [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: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 50 a5 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:ffff8881d8bce9d8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff10a3f59 RBX: 0000000000000200 RCX: 1ffff1103e7c3d3a RDX: 0000000000000000 RSI: ffff8881f3e1e9b0 RDI: 0000000000000282 RBP: ffff8881d8bcea50 R08: ffff8881f3e1e9d0 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff88c16160 R15: ffffffff88c16130 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+0x1eb2/0x1ed0 net/ipv6/addrconf.c:3528 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+0xd4/0x100 net/core/dev.c:1349 do_setlink+0x1b1a/0x2e10 net/core/rtnetlink.c:2661 rtnl_group_changelink net/core/rtnetlink.c:2925 [inline] rtnl_newlink+0x81f/0x1320 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+0x765/0xc40 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: 0033:0x45c4a9 Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f43e75c4c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f43e75c56d4 RCX: 000000000045c4a9 RDX: 0000000000000084 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 000000000076c1a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000009f9 R14: 00000000004cc75a R15: 000000000076c1ac Modules linked in: ---[ end trace a2865018074cadf1 ]--- 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:ffff8881f69077e0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffff895b23e0 RCX: ffff8881f3f7ef38 RDX: 00000000000086dd RSI: 0007000460070004 RDI: ffffffff895b2600 RBP: ffff8881f6907820 R08: ffff8881edeada90 R09: 0000000000000038 R10: 1ffff1103a089e1e R11: 0000000000000000 R12: 0038002300380022 R13: ffff8881cf566200 R14: ffff8881cf566200 R15: ffff8881f3f7edc0 FS: 00007f43e75c5700(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000071e434 CR3: 00000001cf41b004 CR4: 00000000001606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400