bisecting fixing commit since 84f5ad468100f86d70096799e4ee716a17c2962f building syzkaller on ddc3e85997efdad885e208db6a98bca86e5dd52f testing commit 84f5ad468100f86d70096799e4ee716a17c2962f with gcc (GCC) 8.1.0 kernel signature: 3893030ddeded2dbb490a7bf712a565a238ea59b1ac7a3d78a07fde514ee9813 run #0: OK run #1: OK run #2: OK run #3: OK run #4: OK run #5: crashed: general protection fault in hsr_check_carrier_and_operstate run #6: crashed: general protection fault in hsr_check_carrier_and_operstate run #7: crashed: general protection fault in hsr_check_carrier_and_operstate run #8: crashed: general protection fault in hsr_check_carrier_and_operstate run #9: crashed: general protection fault in hsr_check_carrier_and_operstate testing current HEAD d7e78d08fa77acdea351c8f628f49ca9a0e1029a testing commit d7e78d08fa77acdea351c8f628f49ca9a0e1029a with gcc (GCC) 8.1.0 kernel signature: 9ebe5b542f30761efa7ecc90798ec1cedc58e93ff8c4cb27303f3c992a840af3 all runs: crashed: general protection fault in hsr_check_carrier_and_operstate revisions tested: 2, total time: 41m24.992633931s (build: 19m48.817802839s, test: 20m13.519939076s) the crash still happens on HEAD commit msg: Linux 4.14.195 crash: general protection fault in hsr_check_carrier_and_operstate device bridge58 entered promiscuous mode device bridge60 entered promiscuous mode device bridge59 entered promiscuous mode 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 Modules linked in: CPU: 1 PID: 29552 Comm: syz-executor980 Not tainted 4.14.195-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88805c460480 task.stack: ffff888021b68000 RIP: 0010:hsr_check_carrier_and_operstate+0x33/0x580 net/hsr/hsr_device.c:116 RSP: 0018:ffff888021b6edb0 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff88802ed5ae00 RCX: 1ffff11005dab5a4 RDX: 0000000000000002 RSI: 0000000000000004 RDI: ffff88802ed5ae20 RBP: ffff888021b6ede0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000028 R11: ffff88805c460480 R12: 0000000000000000 R13: 0000000000000004 R14: 0000000000000010 R15: ffff88808c2cf700 FS: 00007f602d0ac700(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1b7c5a64f8 CR3: 000000006d218000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: hsr_netdev_notify+0x535/0x9b0 net/hsr/hsr_main.c:51 notifier_call_chain+0xd6/0x150 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+0x4b/0x60 net/core/dev.c:1667 netdev_state_change+0xb5/0xe0 net/core/dev.c:1314 do_setlink+0x197f/0x2c50 net/core/rtnetlink.c:2280 rtnl_newlink+0xe5a/0x13a0 net/core/rtnetlink.c:2660 rtnetlink_rcv_msg+0x34c/0x9e0 net/core/rtnetlink.c:4316 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4328 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x40b/0x600 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x730/0xbd0 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0xf0 net/socket.c:656 ___sys_sendmsg+0x625/0x920 net/socket.c:2062 __sys_sendmsg+0xc1/0x140 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0xd/0x20 net/socket.c:2103 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x446df9 RSP: 002b:00007f602d0abdb8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000006dbc78 RCX: 0000000000446df9 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000009 RBP: 00000000006dbc70 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 00000000006dbc7c R13: 00007ffe55e2c09f R14: 00007f602d0ac9c0 R15: 20c49ba5e353f7cf Code: e5 41 57 41 56 41 55 41 54 53 48 83 ec 08 e8 a5 a6 ff ff 4c 8d 70 10 49 89 c4 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 c3 04 00 00 48 b8 00 00 00 00 00 fc ff df 49 RIP: hsr_check_carrier_and_operstate+0x33/0x580 net/hsr/hsr_device.c:116 RSP: ffff888021b6edb0 ---[ end trace b5d21aa51474c5b9 ]---