bisecting fixing commit since 84f5ad468100f86d70096799e4ee716a17c2962f building syzkaller on ddc3e85997efdad885e208db6a98bca86e5dd52f testing commit 84f5ad468100f86d70096799e4ee716a17c2962f with gcc (GCC) 8.4.1 20210217 kernel signature: 49a346460f5901902d7900f7d0b731d61493fc965658630dbfbfd91408167a90 all runs: crashed: general protection fault in hsr_check_carrier_and_operstate testing current HEAD cf256fbcbe347b7d0ff58fe2dfa382a156bd3694 testing commit cf256fbcbe347b7d0ff58fe2dfa382a156bd3694 with gcc (GCC) 8.4.1 20210217 kernel signature: bd7821ca63feeeeee34109b710b73b7e855820109198a74b3231379eeba0f441 all runs: crashed: general protection fault in hsr_check_carrier_and_operstate revisions tested: 2, total time: 28m21.106738121s (build: 20m7.797764305s, test: 7m19.517165162s) the crash still happens on HEAD commit msg: Linux 4.14.231 crash: general protection fault in hsr_check_carrier_and_operstate device ipvlan1 left promiscuous mode device bridge19 entered promiscuous mode device bridge2 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: 0 PID: 7911 Comm: syz-executor.4 Not tainted 4.14.231-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8881e94d2340 task.stack: ffff8881d2650000 RIP: 0010:hsr_check_carrier_and_operstate+0x33/0x590 net/hsr/hsr_device.c:116 RSP: 0018:ffff8881d2656da8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8881e83af300 RCX: 1ffff1103d075e54 RDX: 0000000000000002 RSI: 0000000000000004 RDI: ffff8881e83af320 RBP: ffff8881d2656dd8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000028 R11: ffff8881e94d2340 R12: 0000000000000000 R13: 0000000000000004 R14: 0000000000000010 R15: ffff8881d2b5cb40 FS: 00007f3cd0a20700(0000) GS:ffff8881f6600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200001c0 CR3: 00000001e36bc004 CR4: 00000000001606f0 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 net/core/dev.c:1314 [inline] netdev_state_change+0xb5/0xe0 net/core/dev.c:1308 do_setlink+0x197f/0x2c50 net/core/rtnetlink.c:2280 rtnl_newlink+0xefd/0x1630 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+0x72f/0xbf0 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: 0033:0x462829 RSP: 002b:00007f3cd0a201a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000052bf00 RCX: 0000000000462829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004fc5e0 R14: 00000000004b5ebd R15: 00007f3cd0a206bc Code: e5 41 57 41 56 41 55 41 54 53 48 83 ec 08 e8 55 a7 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 d9 04 00 00 48 b8 00 00 00 00 00 fc ff df 49 RIP: hsr_check_carrier_and_operstate+0x33/0x590 net/hsr/hsr_device.c:116 RSP: ffff8881d2656da8 ---[ end trace 7338f4a1498333f5 ]---