INFO: task syz.3.1808:9965 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1808 state:D stack:25464 pid: 9965 ppid: 4196 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
rwsem_down_read_slowpath+0x548/0x9d0 kernel/locking/rwsem.c:1055
__down_read_common kernel/locking/rwsem.c:1239 [inline]
__down_read kernel/locking/rwsem.c:1252 [inline]
down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500
iterate_supers+0xa4/0x1d0 fs/super.c:716
quota_sync_all fs/quota/quota.c:68 [inline]
__do_sys_quotactl fs/quota/quota.c:936 [inline]
__se_sys_quotactl+0x33b/0x6f0 fs/quota/quota.c:915
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: 0033:0x7f2387acfdd9
RSP: 002b:00007f2385d29028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f2387d48fa0 RCX: 00007f2387acfdd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101
RBP: 00007f2387b65d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2387d49038 R14: 00007f2387d48fa0 R15: 00007ffe3d6b56f8
INFO: task syz.1.1819:10003 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1819 state:D stack:25808 pid:10003 ppid: 4197 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
rwsem_down_read_slowpath+0x548/0x9d0 kernel/locking/rwsem.c:1055
__down_read_common kernel/locking/rwsem.c:1239 [inline]
__down_read kernel/locking/rwsem.c:1252 [inline]
down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500
iterate_supers+0xa4/0x1d0 fs/super.c:716
quota_sync_all fs/quota/quota.c:68 [inline]
__do_sys_quotactl fs/quota/quota.c:936 [inline]
__se_sys_quotactl+0x33b/0x6f0 fs/quota/quota.c:915
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: 0033:0x7fb467a17dd9
RSP: 002b:00007fb465c71028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007fb467c90fa0 RCX: 00007fb467a17dd9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff80000101
RBP: 00007fb467aadd69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb467c91038 R14: 00007fb467c90fa0 R15: 00007ffc7f1609a8
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c31eb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/u4:4/3029:
1 lock held by udevd/3562:
#0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa5/0x140 kernel/sched/core.c:483
2 locks held by getty/3949:
#0: ffff88802c6cc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
3 locks held by kworker/0:9/5586:
#0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc900033cfd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
#2: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#2: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
2 locks held by kworker/0:20/5604:
#0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1
#1: ffffc900033bfd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285
1 lock held by syz.5.1729/9718:
#0: ffff8880202500e0 (&type->s_umount_key#69/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.3.1808/9965:
#0: ffff8880202500e0 (&type->s_umount_key#98){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz.1.1819/10003:
#0: ffff8880202500e0 (&type->s_umount_key#98){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz-executor/11446:
#0: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
#0: ffffffff8c3235a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.0.2354/11974:
#0: ffff8880202500e0 (&type->s_umount_key#98){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
2 locks held by syz-executor/12395:
#0: ffff888147410118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#1: ffff88802046e468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729