Have pending ack frames! WARNING: CPU: 0 PID: 26606 at net/mac80211/main.c:1384 ieee80211_free_ack_frame+0x48/0x50 net/mac80211/main.c:1384 Modules linked in: CPU: 0 PID: 26606 Comm: kworker/u4:9 Not tainted 5.11.0-rc4-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+0x48/0x50 net/mac80211/main.c:1384 Code: e8 7d 59 27 f9 48 89 ef e8 b5 00 a6 fe 31 c0 5b 5d c3 e8 6b 59 27 f9 48 c7 c7 00 b4 62 8a c6 05 90 f8 a3 04 01 e8 dc 5d 6d 00 <0f> 0b eb d2 0f 1f 40 00 41 57 41 56 41 55 49 89 d5 41 54 49 89 f4 RSP: 0018:ffffc9001857f9d8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88805afe0000 RSI: ffffffff815b6b65 RDI: fffff520030aff2d RBP: ffff88801c047dc0 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815afd3e R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff884b7070 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055a73333b160 CR3: 000000002d9ac000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: idr_for_each+0x113/0x220 lib/idr.c:208 ieee80211_free_hw+0x9b/0x2a0 net/mac80211/main.c:1400 mac80211_hwsim_del_radio drivers/net/wireless/mac80211_hwsim.c:3363 [inline] hwsim_exit_net+0x5bc/0xc90 drivers/net/wireless/mac80211_hwsim.c:4115 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:187 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:604 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296