syzbot


WARNING in ieee80211_determine_chan_mode

Status: upstream: reported C repro on 2025/12/02 08:10
Subsystems: wireless
[Documentation on labels]
Reported-by: syzbot+639af5aa411f2581ad38@syzkaller.appspotmail.com
First crash: 4d11h, last: 4d11h
Discussions (3)
Title Replies (including bot) Last reply
[PATCH wireless v2] wifi: mac80211: don't WARN for connections on invalid channels 1 (1) 2025/12/02 09:25
[PATCH wireless] wifi: mac80211: don't WARN for connections on invalid channels 1 (1) 2025/12/02 09:24
[syzbot] [wireless?] WARNING in ieee80211_determine_chan_mode 0 (1) 2025/12/02 08:10

Sample crash report:
wlan1: No basic rates, using min rate instead
------------[ cut here ]------------
WARNING: CPU: 3 PID: 6085 at net/mac80211/mlme.c:1129 ieee80211_determine_chan_mode+0x13a0/0x41b0 net/mac80211/mlme.c:1129
Modules linked in:
CPU: 3 UID: 0 PID: 6085 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:ieee80211_determine_chan_mode+0x13a0/0x41b0 net/mac80211/mlme.c:1129
Code: 4c 24 08 ba 01 00 00 00 8b 41 04 83 f8 00 0f 47 c2 89 41 04 e9 da f6 ff ff 4d 89 e7 4c 8b a4 24 a0 00 00 00 e8 61 00 ce f6 90 <0f> 0b 90 e9 da fc ff ff e8 53 00 ce f6 90 0f 0b 90 e9 45 fa ff ff
RSP: 0018:ffffc9000413e6d0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffffffff8aeee63e
RDX: ffff888029858000 RSI: ffffffff8aeee77f RDI: 0000000000000005
RBP: ffffed1009b74af6 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888025dc3000 R12: 1ffff92000827cf7
R13: ffffc9000413ea08 R14: ffffc9000413ea10 R15: ffff888025dc3000
FS:  00007f6cc669e6c0(0000) GS:ffff8880d6d05000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e663fff CR3: 0000000053ab0000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ieee80211_prep_channel+0x218/0x18c0 net/mac80211/mlme.c:6059
 ieee80211_prep_connection+0x6df/0x1930 net/mac80211/mlme.c:9030
 ieee80211_mgd_auth+0xdd3/0x19d0 net/mac80211/mlme.c:9320
 rdev_auth net/wireless/rdev-ops.h:486 [inline]
 cfg80211_mlme_auth+0x564/0x980 net/wireless/mlme.c:291
 cfg80211_conn_do_work+0x64c/0xfd0 net/wireless/sme.c:182
 cfg80211_sme_connect net/wireless/sme.c:625 [inline]
 cfg80211_connect+0x1365/0x2130 net/wireless/sme.c:1527
 nl80211_connect+0x1560/0x2140 net/wireless/nl80211.c:13298
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
 __sys_sendmsg+0x16d/0x220 net/socket.c:2716
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6cc578f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6cc669e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f6cc59e5fa0 RCX: 00007f6cc578f7c9
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000003
RBP: 00007f6cc5813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6cc59e6038 R14: 00007f6cc59e5fa0 R15: 00007ffed3637698
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/28 08:04 upstream aa7243aaf194 e8331348 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in ieee80211_determine_chan_mode
* Struck through repros no longer work on HEAD.