syzbot

=============================
WARNING: suspicious RCU usage
5.7.0-rc5-next-20200514-syzkaller #0 Not tainted
-----------------------------
drivers/net/hamradio/bpqether.c:149 RCU-list traversed in non-reader section!!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/3954:
stack backtrace:
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 bpq_get_ax25_dev drivers/net/hamradio/bpqether.c:149 [inline]
 bpq_device_event+0x796/0x8ee drivers/net/hamradio/bpqether.c:538
 notifier_call_chain+0xc0/0x230 kernel/notifier.c:83
 call_netdevice_notifiers_info net/core/dev.c:2016 [inline]
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2001
 call_netdevice_notifiers_extack net/core/dev.c:2028 [inline]
 call_netdevice_notifiers net/core/dev.c:2042 [inline]
 __dev_notify_flags+0x121/0x2c0 net/core/dev.c:8279
 dev_change_flags+0x100/0x160 net/core/dev.c:8317
 do_setlink+0xa1c/0x35d0 net/core/rtnetlink.c:2605
 __rtnl_newlink+0xad0/0x1590 net/core/rtnetlink.c:3273
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3398
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5461
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2469
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6e6/0x810 net/socket.c:2352
 ___sys_sendmsg+0x100/0x170 net/socket.c:2406
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x7fe3a663edc7
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb cd 66 0f 1f 44 00 00 8b 05 4a 49 2b 00 85 c0 75 2e 48 63 ff 48 63 d2 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 a1 f0 2a 00 f7 d8 64 89 02 48
RSP: 002b:00007ffdeddb95a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000005ebe89cb RCX: 00007fe3a663edc7
RDX: 0000000000000000 RSI: 00007ffdeddb95f0 RDI: 0000000000000003
RBP: 00007ffdeddb95f0 R08: 0000000000001000 R09: fefefeff77686d74
R10: 00000000000005e9 R11: 0000000000000246 R12: 00007ffdeddb9630
R13: 000055c97ece33c0 R14: 00007ffdeddc16b0 R15: 0000000000000000