------------[ cut here ]------------
Have pending ack frames!
WARNING: CPU: 0 PID: 8674 at net/mac80211/main.c:1384 ieee80211_free_ack_frame+0x3d/0x50 net/mac80211/main.c:1384
Modules linked in:

CPU: 0 PID: 8674 Comm: kworker/u4:2 Not tainted 5.11.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net

RIP: 0010:ieee80211_free_ack_frame+0x3d/0x50 net/mac80211/main.c:1384
Code: c9 8c 9c f8 48 89 df e8 e1 0f a2 fe 31 c0 5b c3 e8 b8 8c 9c f8 c6 05 6b 58 c5 04 01 48 c7 c7 60 7b ef 8a 31 c0 e8 03 00 6c f8 <0f> 0b eb d6 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 55 41 57
RSP: 0018:ffffc9000231fb08 EFLAGS: 00010246

RAX: fd2fbd118bf54e00 RBX: ffff88802619c780 RCX: ffff88802b3d5340
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffff888142a02c30 R08: ffffffff815fb522 R09: ffffed1017384004
R10: ffffed1017384004 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92000463f68 R14: dffffc0000000000 R15: 1ffff92000463f67
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe4ee0ba000 CR3: 0000000026bda000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 idr_for_each+0x15d/0x250 lib/idr.c:208
 ieee80211_free_hw+0xc0/0x3c0 net/mac80211/main.c:1400
 mac80211_hwsim_del_radio+0x27e/0x3e0 drivers/net/wireless/mac80211_hwsim.c:3363
 hwsim_exit_net+0x553/0x5e0 drivers/net/wireless/mac80211_hwsim.c:4115
 ops_exit_list net/core/net_namespace.c:187 [inline]
 cleanup_net+0x708/0xbd0 net/core/net_namespace.c:604
 process_one_work+0x789/0xfc0 kernel/workqueue.c:2275
 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421
 kthread+0x39a/0x3c0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296