INFO: task syz.7.253:7883 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.253 state:D stack:28864 pid:7883 tgid:7839 ppid:7060 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]
link_path_walk+0xd1e/0x18d0 fs/namei.c:2647
path_parentat fs/namei.c:2851 [inline]
__filename_parentat+0x27f/0x6f0 fs/namei.c:2875
filename_parentat fs/namei.c:2893 [inline]
filename_renameat2+0x22d/0x9c0 fs/namei.c:6090
__do_sys_rename fs/namei.c:6188 [inline]
__se_sys_rename+0x55/0x2c0 fs/namei.c:6184
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: 0033:0x7fa34134c799
RSP: 002b:00007fa33f585028 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 00007fa3415c6090 RCX: 00007fa34134c799
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000200000000300
RBP: 00007fa3413e2c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa3415c6128 R14: 00007fa3415c6090 R15: 00007ffeb2418ca8
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb9c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:10/1385:
4 locks held by kworker/u8:18/1523:
#0: ffff88801e6de938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801e6de938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc900064efc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc900064efc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff888060bca0d0 (&type->s_umount_key#88){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff8880610fb2a8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
2 locks held by getty/5563:
#0: ffff8880370270a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211
4 locks held by syz.7.253/7841:
1 lock held by syz.7.253/7883:
#0: ffff8880610fb678 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline]
#0: ffff8880610fb678 (&type->i_mutex_dir_key#18){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1932
2 locks held by syz.6.453/9308:
#0: ffff888060bca0d0 (&type->s_umount_key#88){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline]
#0: ffff888060bca0d0 (&type->s_umount_key#88){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122
#1: ffff8880259c88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:398 [inline]
#1: ffff8880259c88c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1c5/0xc10 fs/fs-writeback.c:2922
=============================================
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 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 1385 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:__lock_acquire+0x46/0x2cf0 kernel/locking/lockdep.c:5093
Code: 24 e0 00 00 00 65 48 8b 05 4f 45 ae 10 48 89 44 24 08 31 ed 83 3d 19 34 ca 0d 00 0f 84 ef 13 00 00 45 89 cf 49 89 f9 48 8b 07 <48> 3d 00 44 12 93 0f 84 da 13 00 00 41 89 cd 41 89 d6 8b 0d 52 51
RSP: 0018:ffffc90005d9f7c8 EFLAGS: 00000002
RAX: ffffffff9959c980 RBX: 0000000000000046 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88805241d098
RBP: 0000000000000000 R08: 0000000000000001 R09: ffff88805241d098
R10: dffffc0000000000 R11: fffffbfff1ed4b77 R12: 0000000000000000
R13: ffff88805241d098 R14: 0000000000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff888126338000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005630d957d168 CR3: 000000003cec2000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:162
rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x157/0x400 kernel/locking/spinlock_rt.c:57
spin_lock_bh include/linux/spinlock_rt.h:90 [inline]
__batadv_dat_purge+0x131/0x400 net/batman-adv/distributed-arp-table.c:173
batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
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