[v5.15] INFO: rcu detected stall in __cfg80211_wext_siwmode

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cc5ec8769306 Linux 5.15.196
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=118fae14580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e1bb6d24ef2164eb
dashboard link: https://syzkaller.appspot.com/bug?extid=2a55a7e67b68c9b02e7e
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ed7568bc5bb4/disk-cc5ec876.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e343e0aaac77/vmlinux-cc5ec876.xz
kernel image: https://storage.googleapis.com/syzbot-assets/089870f2a980/bzImage-cc5ec876.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2a55a7...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-....: (1 GPs behind) idle=7fd/1/0x4000000000000002 softirq=11033/11041 fqs=5249
(detected by 1, t=10502 jiffies, g=13101, q=756)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6266 Comm: syz.3.565 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:check_preemption_disabled+0x3/0x110 lib/smp_processor_id.c:13
Code: c7 c7 20 dd 12 8a e8 2c 01 00 00 65 ff 0d 91 d6 59 76 5b c3 00 00 cc 48 c7 c7 20 e5 59 8a 48 c7 c6 60 e5 59 8a eb 00 55 41 57 <41> 56 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65
RSP: 0018:ffffc90000007930 EFLAGS: 00000006
RAX: 0000000000010100 RBX: ffff8880b9027780 RCX: dffffc0000000000
RDX: 1ffffffff1dda600 RSI: ffffffff8a59e560 RDI: ffffffff8a59e520
RBP: 0000000000000000 R08: ffffffff8eed3008 R09: ffffffff8eed3018
R10: ffffffff8eed3010 R11: ffffffff8eed3003 R12: ffff8880b9027790
R13: 00000000000001c7 R14: ffff8880278a1dc0 R15: 00000032babf53fa
FS: 00007f38d807b6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2511a3 CR3: 000000001ba56000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
<IRQ>
irqtime_account_delta kernel/sched/cputime.c:37 [inline]
irqtime_account_irq+0xb2/0x1b0 kernel/sched/cputime.c:72
account_hardirq_exit include/linux/vtime.h:159 [inline]
__irq_exit_rcu+0x8d/0x220 kernel/softirq.c:656
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
sysvec_irq_work+0x4f/0xc0 arch/x86/kernel/irq_work.c:17
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ed 11 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007ae0 EFLAGS: 00000206
RAX: bc8f6d162f155600 RBX: 1ffff92000000f60 RCX: bc8f6d162f155600
RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580
RBP: ffffc90000007bb8 R08: dffffc0000000000 R09: fffffbfff1ff7c1d
R10: fffffbfff1ff7c1d R11: 1ffffffff1ff7c1c R12: ffffffff8c120c00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831
mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749
hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766
handle_softirqs+0x328/0x820 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:arch_atomic_set arch/x86/include/asm/atomic.h:41 [inline]
RIP: 0010:atomic_set include/linux/atomic/atomic-instrumented.h:42 [inline]
RIP: 0010:inode_init_always+0x28c/0xcb0 fs/inode.c:176
Code: 0f b6 0c 29 84 c9 0f 85 86 07 00 00 89 43 08 4c 8d bb 10 02 00 00 4c 89 ff be 04 00 00 00 e8 1b 21 ef ff 4c 89 f8 48 c1 e8 03 <0f> b6 04 28 84 c0 4c 8b 2c 24 0f 85 7c 07 00 00 c7 83 10 02 00 00
RSP: 0018:ffffc90002e3f7f0 EFLAGS: 00000a06
RAX: 1ffff1100c055e96 RBX: ffff8880602af2a0 RCX: ffffffff81cd14b5
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8880602af4b0
RBP: dffffc0000000000 R08: dffffc0000000000 R09: ffffed100c055e97
R10: ffffed100c055e97 R11: 1ffff1100c055e96 R12: ffff8880602af2a8
R13: ffff8881407c27f0 R14: 1ffff1100c055e59 R15: ffff8880602af4b0
alloc_inode fs/inode.c:268 [inline]
new_inode_pseudo+0x8e/0x210 fs/inode.c:1001
new_inode+0x25/0x1c0 fs/inode.c:1030
debugfs_get_inode fs/debugfs/inode.c:72 [inline]
__debugfs_create_file+0x148/0x510 fs/debugfs/inode.c:409
add_common_files net/mac80211/debugfs_netdev.c:681 [inline]
add_files net/mac80211/debugfs_netdev.c:807 [inline]
ieee80211_debugfs_add_netdev+0x3b7/0xec0 net/mac80211/debugfs_netdev.c:843
ieee80211_runtime_change_iftype net/mac80211/iface.c:1735 [inline]
ieee80211_if_change_type+0x575/0x9c0 net/mac80211/iface.c:1757
ieee80211_change_iface+0x57/0x420 net/mac80211/cfg.c:160
rdev_change_virtual_intf net/wireless/rdev-ops.h:69 [inline]
cfg80211_change_iface+0x770/0xeb0 net/wireless/util.c:1074
cfg80211_wext_siwmode net/wireless/wext-compat.c:66 [inline]
__cfg80211_wext_siwmode+0x1b4/0x270 net/wireless/wext-compat.c:1569
ioctl_standard_call+0xd4/0x2b0 net/wireless/wext-core.c:1026
wireless_process_ioctl net/wireless/wext-core.c:964 [inline]
wext_ioctl_dispatch+0x3da/0x470 net/wireless/wext-core.c:997
wext_handle_ioctl+0x104/0x1c0 net/wireless/wext-core.c:1058
sock_ioctl+0x145/0x6e0 net/socket.c:1201
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f38d9e13fc9
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:00007f38d807b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f38da06afa0 RCX: 00007f38d9e13fc9
RDX: 0000200000000080 RSI: 0000000000008b06 RDI: 0000000000000003
RBP: 00007f38d9e96f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f38da06b038 R14: 00007f38da06afa0 R15: 00007fffe204ffa8
</TASK>


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