------------[ cut here ]------------
!cfg80211_chandef_valid(chandef)
WARNING: net/wireless/chan.c:796 at cfg80211_chandef_dfs_required+0xe06/0xec0, CPU#1: syz.1.4997/17464
Modules linked in:
CPU: 1 UID: 0 PID: 17464 Comm: syz.1.4997 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:cfg80211_chandef_dfs_required+0xe06/0xec0
Code: de e8 5e b9 c1 f6 48 83 fb 3f 0f 87 aa 00 00 00 e8 0f b5 c1 f6 b8 01 00 00 00 89 d9 48 d3 e0 e9 41 f4 ff ff e8 fb b4 c1 f6 90 <0f> 0b 90 b8 ea ff ff ff e9 2e f4 ff ff e8 68 99 a4 00 89 d1 80 e1
RSP: 0018:ffffc9000a1af700 EFLAGS: 00010283
RAX: ffffffff8b040a75 RBX: ffff88811b4b5858 RCX: 0000000000080000
RDX: ffffc90007849000 RSI: 00000000000005c3 RDI: 00000000000005c4
RBP: ffffc9000a1af890 R08: ffffffff9030aff7 R09: 1ffffffff20615fe
R10: dffffc0000000000 R11: fffffbfff20615ff R12: 0000000000000006
R13: dffffc0000000000 R14: ffffc9000a1afa00 R15: dffffc0000000000
FS:  00007fd5f63d16c0(0000) GS:ffff8882a928f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd5f564f0d1 CR3: 00000001912e6000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 _ieee80211_link_use_channel+0x27a/0x7f0
 ieee80211_set_monitor_channel+0x692/0x8e0
 cfg80211_set_monitor_channel+0x22d/0x5f0
 cfg80211_wext_siwfreq+0x713/0x850
 ioctl_standard_call+0xcb/0x1b0
 wext_ioctl_dispatch+0xee/0x410
 wext_handle_ioctl+0x10f/0x1d0
 sock_ioctl+0x159/0x7f0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd5f559cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd5f63d1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd5f5815fa0 RCX: 00007fd5f559cdd9
RDX: 0000200000000040 RSI: 0000000000008b04 RDI: 0000000000000003
RBP: 00007fd5f5632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd5f5816038 R14: 00007fd5f5815fa0 R15: 00007ffcc2662f28
 </TASK>
