WARNING in drv_unassign_vif_chanctx (4)

Status: upstream: reported on 2026/08/13 00:09
Subsystems: wireless
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+63a84ea9c0f57d6133fa@syzkaller.appspotmail.com
First crash: 27d, last: 2d01h
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
679f3148 repro-c 💥 WARNING in drv_unassign_vif_chanctx (4) 2026/08/13 14:12 2026/08/13 14:12 2026/08/13 19:49 0165196a
4257e155 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in drv_unassign_vif_chanctx (4) 2026/08/10 00:28 2026/08/10 00:28 2026/08/10 01:42 5d63f80b
Discussions (2)
Title Replies (including bot) Last reply
[PATCH wireless 09/10] wifi: mac80211: mesh: release the channel if start fails 1 (1) 2026/09/04 14:58
[syzbot] [wireless?] WARNING in drv_unassign_vif_chanctx (4) 0 (1) 2026/08/13 00:09
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in drv_unassign_vif_chanctx wireless -1 2 921d 921d 0/29 auto-obsoleted due to no activity on 2024/06/05 06:49
upstream WARNING in drv_unassign_vif_chanctx (3) wireless -1 syz, C 2965 266d 395d 0/29 auto-obsoleted due to no activity on 2026/02/20 22:07
upstream WARNING in drv_unassign_vif_chanctx (2) wireless -1 1 618d 614d 0/29 auto-obsoleted due to no activity on 2025/04/04 09:01

Sample crash report:
------------[ cut here ]------------
wlan0: Failed check-sdata-in-driver check, flags: 0x0
WARNING: net/mac80211/driver-ops.c:366 at drv_unassign_vif_chanctx+0x1ef/0x820 net/mac80211/driver-ops.c:366, CPU#0: syz.3.1749/12629
Modules linked in:
CPU: 0 UID: 0 PID: 12629 Comm: syz.3.1749 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
RIP: 0010:drv_unassign_vif_chanctx+0x1f7/0x820 net/mac80211/driver-ops.c:366
Code: 00 00 e8 3c 44 d0 f6 48 8b 34 24 48 81 c6 20 01 00 00 48 89 34 24 e8 28 44 d0 f6 48 8d 3d 61 84 1a 06 8b 54 24 0c 48 8b 34 24 <67> 48 0f b9 3a eb 07 4c 8d b3 68 0a 00 00 e8 06 44 d0 f6 4c 89 f2
RSP: 0018:ffffc900038bf0e0 EFLAGS: 00010202
RAX: 0000000000000003 RBX: ffff888059230ec0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff888059230120 RDI: ffffffff91563050
RBP: ffff888059270f40 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000000b9ec R12: ffff888059232f88
R13: ffff888059a6a400 R14: ffff888059231928 R15: ffff888059232c70
FS:  00007f82936e96c0(0000) GS:ffff888123b61000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f828c000020 CR3: 0000000075e5b000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 ieee80211_assign_link_chanctx+0x5ec/0xeb0 net/mac80211/chan.c:1201
 __ieee80211_link_release_channel+0x2f8/0x5b0 net/mac80211/chan.c:2178
 ieee80211_link_release_channel+0x128/0x200 net/mac80211/chan.c:2494
 ieee80211_teardown_sdata+0xc4/0x250 net/mac80211/iface.c:916
 ieee80211_if_change_type+0x29f/0x790 net/mac80211/iface.c:2088
 ieee80211_change_iface+0xad/0x920 net/mac80211/cfg.c:271
 rdev_change_virtual_intf net/wireless/rdev-ops.h:74 [inline]
 cfg80211_change_iface+0x569/0xdf0 net/wireless/util.c:1310
 nl80211_set_interface+0x875/0xc80 net/wireless/nl80211.c:5108
 genl_family_rcv_msg_doit+0x214/0x300 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x560/0x800 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2556
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:800 [inline]
 __sock_sendmsg net/socket.c:815 [inline]
 ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2713
 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2767
 __sys_sendmsg+0x160/0x210 net/socket.c:2799
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f829279e159
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:00007f82936e9028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8292a26090 RCX: 00007f829279e159
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000007
RBP: 00007f8292835024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8292a26128 R14: 00007f8292a26090 R15: 00007fffb5a0f5b8
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	e8 3c 44 d0 f6       	call   0xf6d04443
   7:	48 8b 34 24          	mov    (%rsp),%rsi
   b:	48 81 c6 20 01 00 00 	add    $0x120,%rsi
  12:	48 89 34 24          	mov    %rsi,(%rsp)
  16:	e8 28 44 d0 f6       	call   0xf6d04443
  1b:	48 8d 3d 61 84 1a 06 	lea    0x61a8461(%rip),%rdi        # 0x61a8483
  22:	8b 54 24 0c          	mov    0xc(%rsp),%edx
  26:	48 8b 34 24          	mov    (%rsp),%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	eb 07                	jmp    0x38
  31:	4c 8d b3 68 0a 00 00 	lea    0xa68(%rbx),%r14
  38:	e8 06 44 d0 f6       	call   0xf6d04443
  3d:	4c 89 f2             	mov    %r14,%rdx

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/03 02:06 upstream 89a312991dc6 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in drv_unassign_vif_chanctx
2026/08/28 11:57 upstream 1b78070aaef6 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in drv_unassign_vif_chanctx
2026/08/15 22:25 upstream 15ef2f78c49d 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in drv_unassign_vif_chanctx
2026/08/08 09:30 upstream 9a143525f62b e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in drv_unassign_vif_chanctx
2026/08/19 10:03 upstream b126f6f5940f 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in drv_unassign_vif_chanctx
* Struck through repros no longer work on HEAD.