bisecting fixing commit since 4fccc2503536a564a4ba31a1d50439854201659f building syzkaller on 2c36e7a75f8689b3da20e1a81a2ee5391f3af6e5 testing commit 4fccc2503536a564a4ba31a1d50439854201659f with gcc (GCC) 8.1.0 kernel signature: 0bd52df61646938b41f6efaf1b3455715c883e804411d9fa9233a0fc28b90558 all runs: crashed: general protection fault in macvlan_hard_header testing current HEAD d18b78abc0c6e7d3119367c931c583e02d466495 testing commit d18b78abc0c6e7d3119367c931c583e02d466495 with gcc (GCC) 8.1.0 kernel signature: 4bf32306d9f2049c819c5ed3cec5e23f5e40f24a5bd0b5db6e7dc40307681152 all runs: crashed: general protection fault in macvlan_hard_header revisions tested: 2, total time: 30m43.314870798s (build: 22m22.562256554s, test: 6m45.238220928s) the crash still happens on HEAD commit msg: Linux 4.19.141 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: 8274 Comm: syz-executor.3 Not tainted 4.19.141-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:ffff8880aeb077e0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffff895b83e0 RCX: ffff888080d297f8 RDX: 00000000000086dd RSI: 0007200000070004 RDI: ffffffff895b8600 RBP: ffff8880aeb07820 R08: ffff88809f55a790 R09: 0000000000000038 R10: 1ffff11012d556d6 R11: 0000000000000000 R12: 0039000000380023 R13: ffff888091b305c0 R14: ffff888091b305c0 R15: ffff888080d29680 FS: 00007f6736654700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e5f439e230 CR3: 00000000943d7000 CR4: 00000000001406e0 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:1703 [inline] run_timer_softirq+0xb63/0x1180 kernel/time/timer.c:1716 __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:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:kfree+0x11a/0x220 mm/slab.c:3823 Code: 1f 44 00 00 e8 37 29 d4 ff 5b 41 5c 41 5d 41 5e 5d c3 e8 99 27 d4 ff 48 83 3d 19 01 c0 06 00 0f 84 07 01 00 00 4c 89 e7 57 9d <0f> 1f 44 00 00 5b 41 5c 41 5d 41 5e 5d c3 4c 89 f2 48 89 de 4c 89 RSP: 0018:ffff888095a86b20 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000007 RBX: ffff888091584080 RCX: 1ffff110109d21ad RDX: 0000000000000000 RSI: ffff888084e90d48 RDI: 0000000000000286 RBP: ffff888095a86b40 R08: ffff888084e90d68 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000286 R13: ffff88812c29cdc0 R14: ffffffff8560b7d4 R15: ffff8880a12d68c0 skb_free_head+0x74/0x90 net/core/skbuff.c:554 pskb_expand_head+0x27a/0xd90 net/core/skbuff.c:1497 netlink_trim+0x1a7/0x200 net/netlink/af_netlink.c:1300 netlink_broadcast_filtered+0x57/0x920 net/netlink/af_netlink.c:1497 netlink_broadcast net/netlink/af_netlink.c:1542 [inline] nlmsg_multicast include/net/netlink.h:591 [inline] nlmsg_notify+0x77/0x120 net/netlink/af_netlink.c:2498 rtnl_notify net/core/rtnetlink.c:736 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:3377 [inline] rtmsg_ifinfo_event.part.32+0x7f/0xb0 net/core/rtnetlink.c:3392 rtmsg_ifinfo_event net/core/rtnetlink.c:3400 [inline] rtmsg_ifinfo+0x4e/0x70 net/core/rtnetlink.c:3398 netdev_state_change+0xe8/0x100 net/core/dev.c:1351 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:00007f6736653c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f67366546d4 RCX: 000000000045c4a9 RDX: 0000000000000084 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000009f9 R14: 00000000004cc75a R15: 000000000076bfcc Modules linked in: ---[ end trace 163280f1c2ef88cd ]--- 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:ffff8880aeb077e0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffffffff895b83e0 RCX: ffff888080d297f8 RDX: 00000000000086dd RSI: 0007200000070004 RDI: ffffffff895b8600 RBP: ffff8880aeb07820 R08: ffff88809f55a790 R09: 0000000000000038 R10: 1ffff11012d556d6 R11: 0000000000000000 R12: 0039000000380023 R13: ffff888091b305c0 R14: ffff888091b305c0 R15: ffff888080d29680 FS: 00007f6736654700(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055e5f439e230 CR3: 00000000943d7000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400