Message-ID: <674525a2.050a0220.1286eb.000b.GAE@google.com>
Date: Mon, 25 Nov 2024 17:34:26 -0800
From: syzbot <syzbot+1fb20cf68d15e7c2388d@...kaller.appspotmail.com>
To: gregkh@...uxfoundation.org, jirislaby@...nel.org, 
	linux-kernel@...r.kernel.org, linux-serial@...r.kernel.org, 
	syzkaller-bugs@...glegroups.com
Subject: [syzbot] [serial?] INFO: task hung in console_callback (5)

Hello,

syzbot found the following issue on:

HEAD commit:    786c8248dbd3 Merge tag 'perf-tools-fixes-for-v6.11-2024-07..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16a068f9980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=fd768013789223fa
dashboard link: https://syzkaller.appspot.com/bug?extid=1fb20cf68d15e7c2388d
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/d1499b23d099/disk-786c8248.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a2ccae57b0f3/vmlinux-786c8248.xz
kernel image: https://storage.googleapis.com/syzbot-assets/501a769c268d/bzImage-786c8248.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1fb20cf68d15e7c2388d@...kaller.appspotmail.com

INFO: task kworker/0:5:5161 blocked for more than 146 seconds.
      Not tainted 6.10.0-syzkaller-12246-g786c8248dbd3 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:5     state:D stack:23680 pid:5161  tgid:5161  ppid:2      flags:0x00004000
Workqueue: events console_callback
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2557
 ___down_common kernel/locking/semaphore.c:225 [inline]
 __down_common+0x343/0x7f0 kernel/locking/semaphore.c:246
 down+0x84/0xc0 kernel/locking/semaphore.c:63
 console_lock+0x145/0x1b0 kernel/printk/printk.c:2735
 console_callback+0x68/0x460 drivers/tty/vt/vt.c:3120
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
 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>

Showing all locks held in the system:
3 locks held by kworker/u8:0/11:
3 locks held by kworker/u8:1/12:
1 lock held by khungtaskd/30:
 #0: ffffffff8e337660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8e337660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e337660 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6620
3 locks held by kworker/u8:2/35:
3 locks held by kworker/1:1/46:
3 locks held by kworker/u8:3/52:
3 locks held by kworker/u8:4/58:
3 locks held by kworker/u8:5/68:
4 locks held by kworker/0:2/922:
 #0: ffff888015079948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015079948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90003b4fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90003b4fd00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8f608748 (rtnl_mutex){+.+.}-{3:3}, at: reg_check_chans_work+0x99/0xfd0 net/wireless/reg.c:2480
 #3: ffff88801eb68768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:6014 [inline]
 #3: ffff88801eb68768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: reg_leave_invalid_chans net/wireless/reg.c:2468 [inline]
 #3: ffff88801eb68768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: reg_check_chans_work+0x164/0xfd0 net/wireless/reg.c:2483
2 locks held by kworker/0:3/925:
3 locks held by kworker/1:2/1106:
3 locks held by kworker/u8:7/2439:
3 locks held by kworker/u8:8/2461:
3 locks held by kworker/u8:9/2821:
2 locks held by getty/4851:
 #0: ffff88802a1050a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f162f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2211
2 locks held by kworker/0:5/5161:
 #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015078948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90002f9fd00 (console_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90002f9fd00 (console_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
2 locks held by kworker/1:4/5162:
3 locks held by kworker/u8:10/5354:
3 locks held by kworker/u8:11/5355:
2 locks held by syz-executor/5752:
6 locks held by syz.2.322/6485:
1 lock held by syz.0.343/6548:
3 locks held by kworker/u8:12/6549:
1 lock held by syz-executor/6550:
2 locks held by kworker/u8:15/6555:
 #0: ffff888015081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc90002d0fd00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc90002d0fd00 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
2 locks held by kworker/u8:16/6556:
 #0: ffff888015081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888015081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000468fd00 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000468fd00 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
3 locks held by kworker/u8:18/6562:
 #0: ffff888029a6b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline]
 #0: ffff888029a6b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312
 #1: ffffc9000483fd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline]
 #1: ffffc9000483fd00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312
 #2: ffffffff8f608748 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734
2 locks held by kworker/u8:19/6565:
1 lock held by udevd/6568:
2 locks held by syz-executor/6569:
1 lock held by syz-executor/6571:

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.10.0-syzkaller-12246-g786c8248dbd3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfee/0x1030 kernel/hung_task.c:379
 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>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 925 Comm: kworker/0:3 Not tainted 6.10.0-syzkaller-12246-g786c8248dbd3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:__lock_acquire+0xe9b/0x2040
Code: 81 e3 00 60 00 00 09 c3 4c 89 f0 48 c1 e8 20 29 c3 89 c1 c1 c1 04 31 d9 44 01 f0 41 29 ce 89 ca c1 c2 06 44 31 f2 01 c1 29 d0 <89> d6 c1 c6 08 31 c6 01 ca 29 f1 89 f3 c1 c3 10 31 cb 01 d6 29 da
RSP: 0018:ffffc90003bb78f0 EFLAGS: 00000093
RAX: 00000000e59244ab RBX: 00000000221d1659 RCX: 00000000b459bc7b
RDX: 00000000d295587c RSI: 0000000000000008 RDI: dffffc0000000000
RBP: ffff888020b12930 R08: ffffffff930028df R09: 1ffffffff260051b
R10: dffffc0000000000 R11: fffffbfff260051c R12: 0000000000000000
R13: ffff888020b128d8 R14: 00000000de128d43 R15: ffff888020b12950
FS:  0000000000000000(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbf6f706000 CR3: 000000005543e000 CR4: 0000000000350ef0
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 wg_ratelimiter_gc_entries+0x60/0x470 drivers/net/wireguard/ratelimiter.c:63
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390
 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>


---
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