syzbot

INFO: task syz-executor:5775 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21288 pid:5775  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 gfs2_gl_hash_clear+0x1b4/0x450 fs/gfs2/glock.c:2238
 gfs2_put_super+0x8bb/0x930 fs/gfs2/super.c:650
 generic_shutdown_super+0x134/0x2b0 fs/super.c:693
 kill_block_super+0x44/0x90 fs/super.c:1660
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd33919bf17
RSP: 002b:00007ffc4e85d9c8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000064 RCX: 00007fd33919bf17
RDX: 0000000000000200 RSI: 0000000000000009 RDI: 00007ffc4e85eb70
RBP: 00007fd33920471f R08: 00000000000105a0 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000202 R12: 00007ffc4e85eb70
R13: 00007fd33920471f R14: 000055558185c4e8 R15: 00007ffc4e85fc40
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d12ffe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d12ffe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d12ffe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:4/77:
2 locks held by getty/5524:
 #0: ffff8880323620a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900015c02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/5775:
 #0: ffff8880601040e0 (&type->s_umount_key#57){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff8880601040e0 (&type->s_umount_key#57){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff8880601040e0 (&type->s_umount_key#57){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
2 locks held by syz-executor/5777:
1 lock held by syz.5.1089/9962:
 #0: ffff8880601040e0 (&type->s_umount_key#57){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff8880601040e0 (&type->s_umount_key#57){++++}-{3:3}, at: super_lock+0x17f/0x3a0 fs/super.c:117
3 locks held by sed/10070:
 #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa9/0x140 kernel/sched/core.c:567
 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2176/0x45a0 kernel/sched/core.c:6695
 #2: ffff888024d85eb8 (&sig->wait_chldexit){....}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:137 [inline]
 #2: ffff888024d85eb8 (&sig->wait_chldexit){....}-{2:2}, at: __wake_up_sync_key+0x101/0x1a0 kernel/sched/wait.c:213

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf3d/0xf80 kernel/hung_task.c:379
 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>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 77 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:preempt_count_sub+0x5/0x160 kernel/sched/core.c:5868
Code: 6e ff ff ff 48 c7 c7 f0 93 8a 8e e8 95 ba 82 00 89 df e9 5b ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 55 <53> 48 bb 00 00 00 00 00 fc ff df 48 c7 c0 80 b4 2a 97 48 c1 e8 03
RSP: 0018:ffffc900020ef280 EFLAGS: 00000293
RAX: ffffffff813b330f RBX: ffffc900020e8001 RCX: ffff88801eeb5a00
RDX: 0000000000000000 RSI: ffffc900020ef360 RDI: 0000000000000001
RBP: ffffc900020ef360 R08: ffff88801eeb5a00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc900020ef3c8
R13: dffffc0000000000 R14: ffffc900020ef3c8 R15: ffffc900020ef3d8
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f30709cbfe8 CR3: 000000000cf30000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 unwind_next_frame+0x1d07/0x2970 arch/x86/kernel/unwind_orc.c:672
 __unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843
 ieee80211_ibss_rx_queued_mgmt+0x1a9e/0x2c80 net/mac80211/ibss.c:-1
 ieee80211_iface_process_skb net/mac80211/iface.c:1651 [inline]
 ieee80211_iface_work+0x717/0xc70 net/mac80211/iface.c:1705
 cfg80211_wiphy_work+0x225/0x260 net/wireless/core.c:437
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa5d/0x15d0 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>