syzbot

INFO: task syz.8.3923:22028 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.3923      state:D stack:22240 pid:22028 tgid:22024 ppid:17986  task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
 __super_lock fs/super.c:59 [inline]
 super_lock+0x2a9/0x3b0 fs/super.c:121
 user_get_super+0xc8/0x120 fs/super.c:998
 quotactl_block fs/quota/quota.c:890 [inline]
 __do_sys_quotactl fs/quota/quota.c:955 [inline]
 __se_sys_quotactl+0x4da/0x950 fs/quota/quota.c:917
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f910c58eec9
RSP: 002b:00007f910d514038 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f910c7e5fa0 RCX: 00007f910c58eec9
RDX: 0000000000000000 RSI: 00002000000080c0 RDI: ffffffff80000901
RBP: 00007f910c611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f910c7e6038 R14: 00007f910c7e5fa0 R15: 00007ffc590f0858
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13a120 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13a120 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13a120 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5617:
 #0: ffff88814cd4e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900036c32f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by syz-executor/10850:
2 locks held by syz-executor/12966:
1 lock held by syz-executor/17988:
 #0: ffffffff8e13fbb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #0: ffffffff8e13fbb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:957
3 locks held by syz-executor/17993:
1 lock held by syz.8.3923/22028:
 #0: ffff88805de6a0e0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff88805de6a0e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
2 locks held by syz-executor/22119:
 #0: ffffffff8e88f0e8 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline]
 #0: ffffffff8e88f0e8 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1764
 #1: ffffffff8e13fa80 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3815

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 23056 Comm: kworker/u8:22 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x35/0xb0 kernel/rcu/tree.c:751
Code: 05 d0 72 fa 10 e8 bb 33 d4 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 10 2d be 8d 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 9c ca 7c 00 48 c7 c3 98 0f a2 92
RSP: 0018:ffffc90004a0e818 EFLAGS: 00000216
RAX: 1ffffffff1b7c5a3 RBX: 0000000000000001 RCX: e13b2b2b8f854400
RDX: 0000000000000000 RSI: ffffffff8be33f60 RDI: ffffffff8be33f20
RBP: ffffffff8172d195 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff52000941d4d R12: 0000000000000002
R13: ffffffff8e13a120 R14: ffffffff8dbe2d18 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125d12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff65f0d980 CR3: 0000000076787000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2422 [inline]
 slab_free mm/slub.c:4695 [inline]
 kfree+0x18e/0x440 mm/slub.c:4894
 ieee80211_inform_bss+0xbd9/0x10a0 net/mac80211/scan.c:160
 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline]
 cfg80211_inform_single_bss_data+0xd05/0x1ac0 net/wireless/scan.c:2380
 cfg80211_inform_bss_data+0x1fb/0x3b30 net/wireless/scan.c:3235
 cfg80211_inform_bss_frame_data+0x3d7/0x730 net/wireless/scan.c:3326
 ieee80211_bss_info_update+0x746/0x9e0 net/mac80211/scan.c:226
 ieee80211_rx_bss_info net/mac80211/ibss.c:1094 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1573 [inline]
 ieee80211_ibss_rx_queued_mgmt+0xa36/0x2ae0 net/mac80211/ibss.c:1600
 ieee80211_iface_process_skb net/mac80211/iface.c:1699 [inline]
 ieee80211_iface_work+0x85f/0x12d0 net/mac80211/iface.c:1753
 cfg80211_wiphy_work+0x2bb/0x470 net/wireless/core.c:435
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>