bisecting fixing commit since 4fccc2503536a564a4ba31a1d50439854201659f building syzkaller on 2c36e7a75f8689b3da20e1a81a2ee5391f3af6e5 testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.1.0 kernel signature: b516d911e96f2d747fa69fb2ad29b8fe26709ab077f3b3807fcedaca34fea614 all runs: crashed: general protection fault in macvlan_hard_header testing current HEAD 14cfdbd39e316efd91ae6e403ef8211f0b022603 testing commit 14cfdbd39e316efd91ae6e403ef8211f0b022603 with gcc (GCC) 8.1.0 kernel signature: 4926894de04c043a6ffc8b7b74eaa02000ad301794f52b52484a4c7c5616618b all runs: crashed: general protection fault in macvlan_hard_header revisions tested: 2, total time: 28m39.025624705s (build: 20m39.913916669s, test: 6m51.970289329s) the crash still happens on HEAD commit msg: Linux 4.19.112 crash: general protection fault in macvlan_hard_header netlink: 8 bytes leftover after parsing attributes in process `syz-executor.5'. IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: 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: 0 PID: 7732 Comm: syz-executor.5 Not tainted 4.19.112-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:ffff8880aea077c0 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffffffff895ad3e0 RCX: ffff8880802e7cb8 RDX: 00000000000086dd RSI: 0007200700000006 RDI: ffffffff895ad600 RBP: ffff8880aea07800 R08: ffff88808c89bb90 R09: 0000000000000038 R10: 1ffff11014b73aae R11: 0000000000000000 R12: 0039003800000037 R13: ffff888083ac8a80 R14: ffff888083ac8a80 R15: ffff8880802e7b40 FS: 00007f385f40b700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdbd03cd10 CR3: 000000008cdb8000 CR4: 00000000001406f0 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:3830 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:893 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:console_unlock+0x904/0xde0 kernel/printk/printk.c:2437 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 c0 8c 04 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:ffff88808b80e9d8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff10a4039 RBX: 0000000000000200 RCX: 1ffff11011c28d59 RDX: 0000000000000000 RSI: ffff88808e146aa8 RDI: 0000000000000286 RBP: ffff88808b80ea50 R08: ffff88808e146ac8 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff88c13720 R15: ffffffff88c136f0 vprintk_emit+0x191/0x540 kernel/printk/printk.c:1937 vprintk_default+0x1a/0x20 kernel/printk/printk.c:1979 vprintk_func+0x49/0x12c kernel/printk/printk_safe.c:398 printk+0x9a/0xc0 kernel/printk/printk.c:2012 addrconf_notify+0x1ed1/0x1ef0 net/ipv6/addrconf.c:3524 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:1748 netdev_state_change+0xd4/0x100 net/core/dev.c:1353 do_setlink+0x1b1a/0x2e10 net/core/rtnetlink.c:2661 rtnl_group_changelink net/core/rtnetlink.c:2925 [inline] rtnl_newlink+0x81a/0x1310 net/core/rtnetlink.c:3083 rtnetlink_rcv_msg+0x34f/0x8f0 net/core/rtnetlink.c:4777 netlink_rcv_skb+0x142/0x390 net/netlink/af_netlink.c:2455 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4795 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: 0033:0x45c429 Code: ad 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f385f40ac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f385f40b6d4 RCX: 000000000045c429 RDX: 0000000000000084 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000009f9 R14: 00000000004cc6da R15: 000000000076bf2c Modules linked in: ---[ end trace 66679c37670af64e ]--- 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:ffff8880aea077c0 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffffffff895ad3e0 RCX: ffff8880802e7cb8 RDX: 00000000000086dd RSI: 0007200700000006 RDI: ffffffff895ad600 RBP: ffff8880aea07800 R08: ffff88808c89bb90 R09: 0000000000000038 R10: 1ffff11014b73aae R11: 0000000000000000 R12: 0039003800000037 R13: ffff888083ac8a80 R14: ffff888083ac8a80 R15: ffff8880802e7b40 FS: 00007f385f40b700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffdbd03cd10 CR3: 000000008cdb8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400