Subject: [syzbot] [wireless?] INFO: task hung in cfg80211_dfs_channels_update_work (7)

From: syzbot <[email-masked]>
Date: Thu, 20 Jun 2024 01:47:25 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    2ccbdf43d5e7 Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16519dde980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fa0ce06dcc735711
dashboard link: https://syzkaller.appspot.com/bug?extid=4f955b33340810d6c105
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/27e64d7472ce/disk-2ccbdf43.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e1c494bb5c9c/vmlinux-2ccbdf43.xz
kernel image: https://storage.googleapis.com/syzbot-assets/752498985a5e/bzImage-2ccbdf43.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

INFO: task kworker/u8:4:61 blocked for more than 143 seconds.
      Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D stack:21872 pid:61    tgid:61    ppid:2      flags:0x00004000
Workqueue: cfg80211 cfg80211_dfs_channels_update_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745
 __schedule_loop kernel/sched/core.c:6822 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6837
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 cfg80211_dfs_channels_update_work+0xbf/0x610 net/wireless/mlme.c:1021
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz-executor.3:7040 blocked for more than 143 seconds.
      Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:25456 pid:7040  tgid:7035  ppid:5121   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745
 __schedule_loop kernel/sched/core.c:6822 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6837
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6894
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 netlink_dump+0x5d3/0xe50 net/netlink/af_netlink.c:2336
 __netlink_dump_start+0x59d/0x780 net/netlink/af_netlink.c:2454
 netlink_dump_start include/linux/netlink.h:340 [inline]
 rtnetlink_dump_start net/core/rtnetlink.c:6524 [inline]
 rtnetlink_rcv_msg+0xda2/0x1180 net/core/rtnetlink.c:6591
 netlink_rcv_skb+0x1e5/0x430 net/netlink/af_netlink.c:2564
 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
 netlink_unicast+0x7ec/0x980 net/netlink/af_netlink.c:1361
 netlink_sendmsg+0x8db/0xcb0 net/netlink/af_netlink.c:1905
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x223/0x270 net/socket.c:745
 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2585

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