[v6.6] WARNING in ieee80211_vif_use_reserved_switch

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 59a2de10b81a Linux 6.6.97
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14f9c0f0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ac0b29aca872266f
dashboard link: https://syzkaller.appspot.com/bug?extid=8adbe2091f52828a621f
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/32864b54a55c/disk-59a2de10.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b0bbe4ada642/vmlinux-59a2de10.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9e3fe91e14c2/bzImage-59a2de10.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8adbe2...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 143 at net/mac80211/chan.c:92 ieee80211_chanctx_reserved_chandef net/mac80211/chan.c:90 [inline]
WARNING: CPU: 1 PID: 143 at net/mac80211/chan.c:92 ieee80211_chsw_switch_hwconf net/mac80211/chan.c:1421 [inline]
WARNING: CPU: 1 PID: 143 at net/mac80211/chan.c:92 ieee80211_vif_use_reserved_switch+0x10e8/0x28f0 net/mac80211/chan.c:1637
Modules linked in:
CPU: 1 PID: 143 Comm: kworker/u4:5 Not tainted 6.6.97-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: phy10 ieee80211_csa_finalize_work

RIP: 0010:ieee80211_chanctx_reserved_chandef net/mac80211/chan.c:92 [inline]
RIP: 0010:ieee80211_chsw_switch_hwconf net/mac80211/chan.c:1421 [inline]
RIP: 0010:ieee80211_vif_use_reserved_switch+0x10e8/0x28f0 net/mac80211/chan.c:1637
Code: 48 89 df e8 1a e1 ea f7 e9 dc fc ff ff e8 50 32 92 f7 eb 24 e8 49 32 92 f7 c7 04 24 f4 ff ff ff e9 e4 f5 ff ff e8 38 32 92 f7 <0f> 0b 0f 0b e9 cf f5 ff ff e8 2a 32 92 f7 48 8b 7c 24 08 4c 8b 7c
RSP: 0018:ffffc90002dc79c0 EFLAGS: 00010293

RAX: ffffffff89f3603e RBX: 0000000000000001 RCX: ffff88801afc8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffff88802d0915af R09: 1ffff11005a122b5
R10: dffffc0000000000 R11: ffffed1005a122b6 R12: 0000000000000001
R13: ffff88802d0925d9 R14: ffff88802d462c70 R15: ffff88802d462ce8
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2a6bc68f98 CR3: 000000002a5ab000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 00000000000000aa
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ieee80211_link_use_reserved_context+0x383/0x5c0 net/mac80211/chan.c:1926
__ieee80211_csa_finalize net/mac80211/cfg.c:3679 [inline]
ieee80211_csa_finalize+0x59a/0xf00 net/mac80211/cfg.c:3718
ieee80211_csa_finalize_work+0xf6/0x140 net/mac80211/cfg.c:3743
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 59a2de10b81a Linux 6.6.97
git tree: linux-6.6.y

console output: https://syzkaller.appspot.com/x/log.txt?x=163b2e8c580000

kernel config: https://syzkaller.appspot.com/x/.config?x=ac0b29aca872266f
dashboard link: https://syzkaller.appspot.com/bug?extid=8adbe2091f52828a621f
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11ec7bd4580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=136d9e8c580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/32864b54a55c/disk-59a2de10.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b0bbe4ada642/vmlinux-59a2de10.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9e3fe91e14c2/bzImage-59a2de10.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8adbe2...@syzkaller.appspotmail.com

------------[ cut here ]------------

WARNING: CPU: 0 PID: 48 at net/mac80211/chan.c:92 ieee80211_chanctx_reserved_chandef net/mac80211/chan.c:90 [inline]
WARNING: CPU: 0 PID: 48 at net/mac80211/chan.c:92 ieee80211_chsw_switch_hwconf net/mac80211/chan.c:1421 [inline]
WARNING: CPU: 0 PID: 48 at net/mac80211/chan.c:92 ieee80211_vif_use_reserved_switch+0x10e8/0x28f0 net/mac80211/chan.c:1637
Modules linked in:

CPU: 0 PID: 48 Comm: kworker/u4:3 Not tainted 6.6.97-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025

Workqueue: phy5 ieee80211_csa_finalize_work

RIP: 0010:ieee80211_chanctx_reserved_chandef net/mac80211/chan.c:92 [inline]
RIP: 0010:ieee80211_chsw_switch_hwconf net/mac80211/chan.c:1421 [inline]
RIP: 0010:ieee80211_vif_use_reserved_switch+0x10e8/0x28f0 net/mac80211/chan.c:1637
Code: 48 89 df e8 1a e1 ea f7 e9 dc fc ff ff e8 50 32 92 f7 eb 24 e8 49 32 92 f7 c7 04 24 f4 ff ff ff e9 e4 f5 ff ff e8 38 32 92 f7 <0f> 0b 0f 0b e9 cf f5 ff ff e8 2a 32 92 f7 48 8b 7c 24 08 4c 8b 7c

RSP: 0018:ffffc90000b8f9c0 EFLAGS: 00010293

RAX: ffffffff89f3603e RBX: 0000000000000001 RCX: ffff88801ce71e00

RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000

RBP: dffffc0000000000 R08: ffff8880737cd5af R09: 1ffff1100e6f9ab5
R10: dffffc0000000000 R11: ffffed100e6f9ab6 R12: 0000000000000001
R13: ffff8880737ce5d9 R14: ffff88802d262c70 R15: ffff88802d262ce8
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 000055557d31d808 CR3: 0000000023cb0000 CR4: 00000000003506f0

Call Trace:
<TASK>
ieee80211_link_use_reserved_context+0x383/0x5c0 net/mac80211/chan.c:1926
__ieee80211_csa_finalize net/mac80211/cfg.c:3679 [inline]
ieee80211_csa_finalize+0x59a/0xf00 net/mac80211/cfg.c:3718
ieee80211_csa_finalize_work+0xf6/0x140 net/mac80211/cfg.c:3743
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>


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