bisecting fixing commit since cbfa1702aaf69b2311ea1b35e04f113c48368c67
building syzkaller on 5ef9c29141f85f210b326ce68718498ae0c1fd35
testing commit cbfa1702aaf69b2311ea1b35e04f113c48368c67 with gcc (GCC) 8.1.0
kernel signature: 95ba8b8551b7180098ba8df56e26f1359204d2f4cb6fbe6db13cbe8effbd39e1
all runs: crashed: WARNING in __cfg80211_ibss_joined
testing current HEAD 3f2ecb86cb909da0b9157fd2952ad79924cbe5ae
testing commit 3f2ecb86cb909da0b9157fd2952ad79924cbe5ae with gcc (GCC) 8.1.0
kernel signature: 97ebe4df8198c1365b15e1c973dd276f68e9ea0e68c3f13e2b6ab77fac2e853c
all runs: crashed: WARNING in __cfg80211_ibss_joined
revisions tested: 2, total time: 37m21.332512361s (build: 17m21.176692464s, test: 19m18.003404491s)
the crash still happens on HEAD
commit msg: Linux 4.14.212
crash: WARNING in __cfg80211_ibss_joined
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
IPv6: ADDRCONF(NETDEV_UP): wlan0: link is not ready
------------[ cut here ]------------
WARNING: CPU: 1 PID: 22 at net/wireless/ibss.c:36 __cfg80211_ibss_joined+0x341/0x420 net/wireless/ibss.c:47
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 22 Comm: kworker/u4:1 Not tainted 4.14.212-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: cfg80211 cfg80211_event_work
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x14b/0x1f1 lib/dump_stack.c:58
 panic+0x1b0/0x358 kernel/panic.c:183
 __warn.cold.7+0x25/0x2c kernel/panic.c:547
 report_bug+0x1a4/0x1f3 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 do_error_trap+0x1bd/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:__cfg80211_ibss_joined+0x341/0x420 net/wireless/ibss.c:36
RSP: 0018:ffff8881f4ddfc00 EFLAGS: 00010246
RAX: 0000000000000002 RBX: ffff8881e9f15010 RCX: 1ffff1103e9ba1dc
RDX: 1ffffffff0fe2bc3 RSI: ffff8881f4dd0ec0 RDI: ffffffff87f15e18
RBP: ffff8881f4ddfca0 R08: ffff8881f4dd0ee0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1103e9bbf82
R13: ffff8881e9f14540 R14: ffff8881ef7eec18 R15: 0000000000000000
 cfg80211_process_wdev_events+0x1c7/0x4f0 net/wireless/util.c:961
 cfg80211_process_rdev_events+0x59/0x90 net/wireless/util.c:984
 cfg80211_event_work+0x19/0x30 net/wireless/core.c:305
 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116
 worker_thread+0xcc/0xed0 kernel/workqueue.c:2250
 kthread+0x338/0x400 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Kernel Offset: disabled
Rebooting in 86400 seconds..