INFO: task syz.2.236:7477 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.236 state:D stack:28712 pid:7477 tgid:7460 ppid:5794 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x1553/0x5240 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1f8f/0x25c0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x132/0x200 kernel/locking/rwsem.c:1539
inode_lock_shared include/linux/fs.h:1043 [inline]
lookup_slow+0x46/0x70 fs/namei.c:1932
walk_component fs/namei.c:2279 [inline]
lookup_last fs/namei.c:2780 [inline]
path_lookupat+0x3f5/0x8c0 fs/namei.c:2804
filename_lookup+0x256/0x5d0 fs/namei.c:2833
user_path_at+0x40/0x160 fs/namei.c:3612
do_mount fs/namespace.c:4169 [inline]
__do_sys_mount fs/namespace.c:4361 [inline]
__se_sys_mount+0x2dc/0x420 fs/namespace.c:4338
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fee8913c799
RSP: 002b:00007fee8734c028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fee893b6180 RCX: 00007fee8913c799
RDX: 0000200000000b80 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 00007fee891d2c99 R08: 0000200000000780 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fee893b6218 R14: 00007fee893b6180 R15: 00007ffcacab3518
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8ddcba00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcba00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcba00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5550:
#0: ffff8880380d60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u9:3/5799:
#0: ffff88803f188138 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88803f188138 ((wq_completion)hci0){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90004687c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90004687c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff888060da8f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
3 locks held by syz.2.236/7461:
1 lock held by syz.2.236/7477:
#0: ffff888061c0d7d0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline]
#0: ffff888061c0d7d0 (&type->i_mutex_dir_key#3){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1932
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7461 Comm: syz.2.236 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_preemption_disabled+0x6/0xe0 lib/smp_processor_id.c:14
Code: c7 c6 e0 6d a6 8b eb 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 <65> 8b 05 47 03 2b 07 65 8b 0d 3c 03 2b 07 f7 c1 ff ff ff 7f 74 0c
RSP: 0018:ffffc900062becb8 EFLAGS: 00000046
RAX: ffff88802c32bd00 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8d57bbe6 RDI: ffffffff8ba66e00
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc900062bee78 R11: ffffffff81af90c0 R12: 0000000000000002
R13: ffffffff8ddcba00 R14: 0000000000000000 R15: 0000000000000000
FS: 00007fee8738e6c0(0000) GS:ffff888126439000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b2009aff98 CR3: 00000000607e8000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
lock_acquire+0xb9/0x2e0 kernel/locking/lockdep.c:5867
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2685 [inline]
slab_free mm/slub.c:6165 [inline]
kfree+0x1c1/0x6c0 mm/slub.c:6483
qtree_write_dquot+0x454/0x5e0 fs/quota/quota_tree.c:-1
v2_write_dquot+0x183/0x260 fs/quota/quota_v2.c:372
dquot_commit+0x377/0x450 fs/quota/dquot.c:515
ext4_write_dquot+0x20a/0x380 fs/ext4/super.c:6977
mark_dquot_dirty fs/quota/dquot.c:373 [inline]
mark_all_dquot_dirty+0x101/0x460 fs/quota/dquot.c:413
__dquot_free_space+0x80b/0xc00 fs/quota/dquot.c:1931
dquot_free_space_nodirty include/linux/quotaops.h:374 [inline]
dquot_free_space include/linux/quotaops.h:379 [inline]
dquot_free_block include/linux/quotaops.h:390 [inline]
ext4_xattr_block_set+0x1487/0x2ad0 fs/ext4/xattr.c:2083
ext4_xattr_set_handle+0xe34/0x14c0 fs/ext4/xattr.c:2457
ext4_initxattrs+0x9f/0x110 fs/ext4/xattr_security.c:44
security_inode_init_security+0x296/0x3d0 security/security.c:1345
__ext4_new_inode+0x332f/0x3d20 fs/ext4/ialloc.c:1324
ext4_mkdir+0x3da/0xbf0 fs/ext4/namei.c:3005
vfs_mkdir+0x40b/0x630 fs/namei.c:5233
filename_mkdirat+0x289/0x520 fs/namei.c:5266
__do_sys_mkdirat fs/namei.c:5287 [inline]
__se_sys_mkdirat+0x35/0x150 fs/namei.c:5284
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fee8913b607
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fee8738de58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fee8738dee0 RCX: 00007fee8913b607
RDX: 00000000000001ff RSI: 0000200000000080 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000080
R13: 00007fee8738dea0 R14: 0000000000000000 R15: 0000000000000000