[syzbot] [wireless?] WARNING: suspicious RCU usage in ieee80211_mesh_csa_beacon (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7a0892d2836e Merge tag 'pci-v6.18-fixes-5' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1100a212580000
kernel config: https://syzkaller.appspot.com/x/.config?x=929790bc044e87d7
dashboard link: https://syzkaller.appspot.com/bug?extid=b59873f5699e941717ca
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12656884580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15519212580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-7a0892d2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a78c5c2efd8d/vmlinux-7a0892d2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5a51cc5df960/bzImage-7a0892d2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b59873...@syzkaller.appspotmail.com

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007f4e229e5fa0 R14: 00007f4e229e5fa0 R15: 0000000000000003
</TASK>
=============================
WARNING: suspicious RCU usage
syzkaller #0 Not tainted
-----------------------------
net/mac80211/mesh.c:1571 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
2 locks held by syz.0.17/5477:
#0: ffffffff8f333750 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffff888059ba0788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: wiphy_lock include/net/cfg80211.h:6343 [inline]
#1: ffff888059ba0788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: nl80211_pre_doit+0x281/0x930 net/wireless/nl80211.c:17999

stack backtrace:
CPU: 0 UID: 0 PID: 5477 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
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
lockdep_rcu_suspicious+0x140/0x1d0 kernel/locking/lockdep.c:6876
ieee80211_mesh_csa_beacon+0x280/0x2c0 net/mac80211/mesh.c:1571
ieee80211_set_csa_beacon+0x3cc/0x9a0 net/mac80211/cfg.c:4288
__ieee80211_channel_switch net/mac80211/cfg.c:4406 [inline]
ieee80211_channel_switch+0x8ef/0xcb0 net/mac80211/cfg.c:4442
rdev_channel_switch+0x108/0x290 net/wireless/rdev-ops.h:1116
nl80211_channel_switch+0xac9/0xd70 net/wireless/nl80211.c:11475
genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x208/0x470 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+0x82f/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg+0x21c/0x270 net/socket.c:742
____sys_sendmsg+0x505/0x830 net/socket.c:2630
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
__sys_sendmsg net/socket.c:2716 [inline]
__do_sys_sendmsg net/socket.c:2721 [inline]
__se_sys_sendmsg net/socket.c:2719 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4e2278f6c9
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:00007ffe9e0535c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4e229e5fa0 RCX: 00007f4e2278f6c9
RDX: 0000000000000000 RSI: 0000200000004180 RDI: 0000000000000003
RBP: 00007ffe9e053620 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007f4e229e5fa0 R14: 00007f4e229e5fa0 R15: 0000000000000003
</TASK>


---
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