INFO: task syz.2.1064:12533 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.1064 state:D stack:26392 pid:12533 tgid:12531 ppid:5805 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
inode_lock include/linux/fs.h:980 [inline]
open_last_lookups fs/namei.c:3892 [inline]
path_openat+0x8e6/0x3840 fs/namei.c:4131
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff99e11eec9
RSP: 002b:00007ff99c365038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff99e376090 RCX: 00007ff99e11eec9
RDX: 000000000000275a RSI: 0000200000000080 RDI: ffffffffffffff9c
RBP: 00007ff99e1a1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff99e376128 R14: 00007ff99e376090 R15: 00007fff04ee58d8
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:4/68:
#0: ffff88814047b138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88814047b138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000153fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000153fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff8880322d60d0 (&type->s_umount_key#76){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
#3: ffff88805d196d28 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
2 locks held by getty/5564:
#0: ffff88823bf540a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
4 locks held by syz.2.1064/12532:
2 locks held by syz.2.1064/12533:
#0: ffff8880322d6480 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:508
#1: ffff88805d1970f8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
#1: ffff88805d1970f8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline]
#1: ffff88805d1970f8 (&type->i_mutex_dir_key#13){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131
2 locks held by syz.8.1202/13407:
#0: ffff8880322d60d0 (&type->s_umount_key#76){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880322d60d0 (&type->s_umount_key#76){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
#1: ffff8880245128c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880245128c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2871
2 locks held by syz.0.1210/13450:
#0: ffff8880322d60d0 (&type->s_umount_key#76){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff8880322d60d0 (&type->s_umount_key#76){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
#1: ffff8880245128c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880245128c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2871
1 lock held by syz.9.1349/14480:
2 locks held by syz.6.1353/14503:
3 locks held by syz.1.1354/14506:
2 locks held by syz.5.1355/14511:
3 locks held by syz.4.1356/14516:
4 locks held by dhcpcd-run-hook/14521:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
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:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4b9/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14503 Comm: syz.6.1353 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4868 [inline]
RIP: 0010:__lock_acquire+0x446/0xd20 kernel/locking/lockdep.c:5187
Code: d3 44 0f b6 e9 44 0f 44 ea 44 8b a7 58 0b 00 00 41 8d 4c 24 ff 83 f9 ff bd ff ff ff ff 0f 4c e9 ff c5 45 8d 7c 24 01 49 ff cc <44> 89 f9 83 c1 fe 78 44 44 89 e3 81 e3 ff ff ff 7f 83 f9 31 73 1d
RSP: 0018:ffffc9000cecf680 EFLAGS: 00000046
RAX: 000000000002000b RBX: 0000000000000000 RCX: 00000000000708c1
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff888034865a00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ac7bb81
R10: 0000000000000000 R11: fffffbfff1deecaf R12: ffffffffffffffff
R13: 0000000000000001 R14: ffff8880348665b0 R15: 0000000000000001
FS: 00007fbdd192e6c0(0000) GS:ffff888126bcd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f86a392d000 CR3: 0000000054174000 CR4: 00000000003526f0
Call Trace:
reacquire_held_locks+0x127/0x1d0 kernel/locking/lockdep.c:5385
__lock_release kernel/locking/lockdep.c:5574 [inline]
lock_release+0x1b4/0x3e0 kernel/locking/lockdep.c:5889
rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80
__dquot_alloc_space+0x285/0xea0 fs/quota/dquot.c:1698
dquot_alloc_space_nodirty include/linux/quotaops.h:299 [inline]
dquot_alloc_block_nodirty include/linux/quotaops.h:326 [inline]
shmem_inode_acct_blocks+0x2a5/0x470 mm/shmem.c:243
shmem_alloc_and_add_folio mm/shmem.c:1940 [inline]
shmem_get_folio_gfp+0x8f0/0x1a70 mm/shmem.c:2533
shmem_get_folio mm/shmem.c:2639 [inline]
shmem_write_begin+0xef/0x2a0 mm/shmem.c:3289
generic_perform_write+0x29d/0x8c0 mm/filemap.c:4242
shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3464
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x5d5/0xb40 fs/read_write.c:686
ksys_write+0x14b/0x260 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbdd36cd97f
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48
RSP: 002b:00007fbdd192ddf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fbdd36cd97f
RDX: 0000000001000000 RSI: 00007fbdc950e000 RDI: 0000000000000006
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009790
R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000006
R13: 00007fbdd192def0 R14: 00007fbdd192deb0 R15: 00007fbdc950e000