bisecting fixing commit since 996e435fd401de35df62ac943ab9402cfe85c430
building syzkaller on 2c1f2513486f21d26b1942ce77ffc782677fbf4e
testing commit 996e435fd401de35df62ac943ab9402cfe85c430
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: f32cb4825361fffe2bfc56a60ae1b225a2c09caa382843176d1fe2bbded41f9a
all runs: crashed: WARNING in sta_info_insert_rcu
testing current HEAD c500bee1c5b2f1d59b1081ac879d73268ab0ff17
testing commit c500bee1c5b2f1d59b1081ac879d73268ab0ff17
compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.1
kernel signature: 39b9c9e3793cdd287c7c267e30987934e7b37274a1839258667e8ccae51ff2d8
all runs: crashed: WARNING in sta_info_insert_rcu
revisions tested: 2, total time: 18m9.467612344s (build: 10m53.345157369s, test: 6m40.567423186s)
the crash still happens on HEAD
commit msg: Linux 5.14-rc4
crash: WARNING in sta_info_insert_rcu
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8 at net/mac80211/sta_info.c:545 sta_info_insert_check net/mac80211/sta_info.c:545 [inline]
WARNING: CPU: 0 PID: 8 at net/mac80211/sta_info.c:545 sta_info_insert_rcu+0x250/0x25b0 net/mac80211/sta_info.c:723
Modules linked in:
CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: phy5 ieee80211_iface_work

RIP: 0010:sta_info_insert_check net/mac80211/sta_info.c:545 [inline]
RIP: 0010:sta_info_insert_rcu+0x250/0x25b0 net/mac80211/sta_info.c:723
Code: 07 83 c0 01 38 c8 7c 08 84 c9 0f 85 67 11 00 00 66 41 33 9c 24 0c 16 00 00 0f b7 db 09 d3 74 0a 41 83 e7 01 0f 84 84 00 00 00 <0f> 0b 41 bf ea ff ff ff 48 8b b5 50 ff ff ff 4c 89 f7 e8 69 fa ff
RSP: 0018:ffffc90000cd79e8 EFLAGS: 00010202
RAX: 0000000000000005 RBX: 00000000bd723777 RCX: 0000000000000000
RDX: 00000000bd722565 RSI: ffff8880292b0ee4 RDI: ffff88804100a20c
RBP: ffffc90000cd7b30 R08: 0000000000000000 R09: ffff88804100925f
R10: ffffed100820124b R11: 0000000000000000 R12: ffff888041008c00
R13: ffff8880279816c0 R14: ffff888027980d20 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000516c70 CR3: 0000000031ac3000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ieee80211_ibss_finish_sta+0x1a1/0x2c0 net/mac80211/ibss.c:592
 ieee80211_ibss_work+0x265/0xcd0 net/mac80211/ibss.c:1700
 process_one_work+0x84c/0x13d0 kernel/workqueue.c:2276
 worker_thread+0x598/0x1040 kernel/workqueue.c:2422
 kthread+0x38b/0x460 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
irq event stamp: 449033
hardirqs last  enabled at (449047): [<ffffffff81476a2d>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1319 [inline]
hardirqs last  enabled at (449047): [<ffffffff81476a2d>] finish_lock_switch kernel/sched/core.c:4437 [inline]
hardirqs last  enabled at (449047): [<ffffffff81476a2d>] finish_task_switch.isra.0+0x22d/0x9e0 kernel/sched/core.c:4555
hardirqs last disabled at (449076): [<ffffffff884b9567>] __schedule+0x1387/0x26a0 kernel/sched/core.c:5836