INFO: task syz.7.636:11771 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.7.636 state:D stack:25184 [ 646.183466][ T38] task:syz.7.636 state:D stack:25184 pid:11771 tgid:11770 ppid:11453 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x14fb/0x52c0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7285
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
filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
do_page_cache_ra mm/readahead.c:333 [inline]
page_cache_ra_order+0x2a5/0x4b0 mm/readahead.c:538
filemap_get_pages+0x47c/0x1ea0 mm/filemap.c:2690
filemap_splice_read+0x5d3/0xd20 mm/filemap.c:3079
do_splice_read fs/splice.c:980 [inline]
splice_direct_to_actor+0x483/0xc80 fs/splice.c:1084
do_splice_direct_actor fs/splice.c:1202 [inline]
do_splice_direct+0x19b/0x2a0 fs/splice.c:1228
do_sendfile+0x547/0x7e0 fs/read_write.c:1372
__do_sys_sendfile64 fs/read_write.c:1433 [inline]
__se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1419
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: 0033:0x7f5777e8c629
RSP: 002b:00007f57760e6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f5778105fa0 RCX: 00007f5777e8c629
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 000000000000000a
RBP: 00007f5777f22b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020fffe85 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5778106038 R14: 00007f5778105fa0 R15: 00007ffc69365908
Showing all locks held in the system:
11 locks held by ktimers/1/29:
#0: ffffffff8dc64fa0 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#1: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
#2: ffff8880b8926420 (&base->expiry_lock){+...}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#2: ffff8880b8926420 (&base->expiry_lock){+...}-{3:3}, at: timer_base_lock_expiry kernel/time/timer.c:1502 [inline]
#2: ffff8880b8926420 (&base->expiry_lock){+...}-{3:3}, at: __run_timer_base+0x120/0x9f0 kernel/time/timer.c:2383
#3: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#3: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#3: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#3: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
#4: ffffc90000a3fa80 ((&ndev->rs_timer)){+...}-{0:0}, at: call_timer_fn+0xd4/0x640 kernel/time/timer.c:1745
#5: ffff88803a9a66c0 (&ndev->lock){++..}-{3:3}, at: write_lock include/linux/rwlock_rt.h:92 [inline]
#5: ffff88803a9a66c0 (&ndev->lock){++..}-{3:3}, at: addrconf_rs_timer+0x39f/0x6d0 net/ipv6/addrconf.c:4046
#6: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#6: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#6: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rt_write_lock+0x86/0x220 kernel/locking/spinlock_rt.c:244
#7: ffff8880b8936f68 ((batched_entropy_u32.lock)){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#7: ffff8880b8936f68 ((batched_entropy_u32.lock)){+.+.}-{3:3}, at: get_random_u32+0x1e0/0x860 drivers/char/random.c:554
#8: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#8: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#8: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
#8: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e0/0x400 kernel/locking/spinlock_rt.c:57
#9: ffff8880b8937110 ((crngs.lock)){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#9: ffff8880b8937110 ((crngs.lock)){+.+.}-{3:3}, at: crng_make_state+0x162/0x5d0 drivers/char/random.c:368
#10: ffff88801d2bc730 (&p->pi_lock){-...}-{2:2}, at: _task_rq_lock+0x5b/0x470 kernel/sched/core.c:745
1 lock held by khungtaskd/38:
#0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:6/307:
#0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888019c44938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90003ae7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90003ae7c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
3 locks held by kworker/1:2/915:
#0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888019c03d38 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90005167c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90005167c40 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
#2: ffff8880659a5260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x222/0x3e0 drivers/net/netdevsim/fib.c:1490
6 locks held by kworker/u8:11/2066:
2 locks held by getty/5548:
#0: ffff8880377a00a0 (&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
2 locks held by syz.1.567/10845:
1 lock held by syz-executor/11478:
1 lock held by udevd/11539:
1 lock held by syz.7.636/11771:
#0: ffff888026131738 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
#0: ffff888026131738 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline]
#0: ffff888026131738 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x4b0 mm/readahead.c:538
1 lock held by syz.3.824/13509:
#0: ffff888026131738 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1093 [inline]
#0: ffff888026131738 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline]
#0: ffff888026131738 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x4b0 mm/readahead.c:538
3 locks held by syz.4.856/13785:
1 lock held by syz.2.858/13796:
2 locks held by syz.6.859/13807:
2 locks held by modprobe/13834:
=============================================
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:467
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: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:io_serial_out+0x7c/0xc0 drivers/tty/serial/8250/8250_port.c:407
Code: 37 95 fc 44 89 f9 d3 e5 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 6c 40 fb fc 41 03 2e 89 d8 89 ea ee <5b> 41 5c 41 5e 41 5f 5d c3 cc cc cc cc cc 44 89 f9 80 e1 07 38 c1
RSP: 0018:ffffc90000167a30 EFLAGS: 00000202
RAX: 0000000000000074 RBX: 0000000000000074 RCX: 0000000000000000
RDX: 00000000000003f8 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000003f8 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff852f1b20 R12: dffffc0000000000
R13: 0000000000000001 R14: ffffffff9994c460 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888126343000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7ca18d8e9c CR3: 000000006bf0c000 CR4: 00000000003526f0
Call Trace:
serial_port_out include/linux/serial_core.h:811 [inline]
serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3192 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:-1 [inline]
serial8250_console_write+0x12e1/0x1b90 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3163 [inline]
console_flush_one_record+0x68b/0xb90 kernel/printk/printk.c:3269
legacy_kthread_func+0x1b6/0x250 kernel/printk/printk.c:3712
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245