bisecting fixing commit since 84f5ad468100f86d70096799e4ee716a17c2962f building syzkaller on ddc3e85997efdad885e208db6a98bca86e5dd52f testing commit 84f5ad468100f86d70096799e4ee716a17c2962f with gcc (GCC) 8.4.1 20210217 kernel signature: 39ef8e46b452ac32ee1150b6aefbfcd236aa82559e16fbae0412180c9f995938 all runs: crashed: general protection fault in hsr_check_carrier_and_operstate testing current HEAD 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79 testing commit 3242aa3a635c0958671ee1e4b0958dcc7c4e5c79 with gcc (GCC) 8.4.1 20210217 kernel signature: 9244be4e734959340c770f0b29968d755b1f7b3638e7aa5f70856b6703e01363 all runs: crashed: general protection fault in hsr_check_carrier_and_operstate revisions tested: 2, total time: 24m0.141454057s (build: 15m59.511261199s, test: 6m39.811401601s) the crash still happens on HEAD commit msg: Linux 4.14.222 crash: general protection fault in hsr_check_carrier_and_operstate hsr7: Cannot create trees of HSR devices. device ipvlan0 entered promiscuous mode device bridge8 left 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: 7808 Comm: syz-executor.1 Not tainted 4.14.222-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8881e9a04440 task.stack: ffff8881d27f8000 RIP: 0010:hsr_check_carrier_and_operstate+0x33/0x590 net/hsr/hsr_device.c:116 RSP: 0018:ffff8881d27feda8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8881f2e87300 RCX: 1ffff1103e5d0e74 RDX: 0000000000000002 RSI: 0000000000000004 RDI: ffff8881f2e87320 RBP: ffff8881d27fedd8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000028 R11: ffff8881e9a04440 R12: 0000000000000000 R13: 0000000000000004 R14: 0000000000000010 R15: ffff8881e7bb3400 FS: 00007fddc3814700(0000) GS:ffff8881f6600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe93000368 CR3: 00000001e9af2002 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+0xeda/0x1610 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:00007fddc38141a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000052bfa8 RCX: 0000000000462829 RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004 RBP: 0000000000000003 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004fc5e0 R14: 00000000004b5ebd R15: 00007fddc38146bc 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: ffff8881d27feda8 ---[ end trace 605afcd817bd52a2 ]---