INFO: task syz.0.16:6454 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.16 state:D stack:24840 pid:6454 tgid:6453 ppid:6272 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x171d/0x56e0 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7724
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked+0x1f86/0x25f0 kernel/locking/rtmutex.c:1787
__rwbase_read_lock+0xc3/0x190 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1502 [inline]
down_read+0x12d/0x200 kernel/locking/rwsem.c:1576
inode_lock_shared include/linux/fs.h:1039 [inline]
blkdev_write_iter+0x4f7/0x700 block/fops.c:783
iter_file_splice_write+0xa36/0x1240 fs/splice.c:736
do_splice_from fs/splice.c:936 [inline]
direct_splice_actor+0x104/0x160 fs/splice.c:1187
splice_direct_to_actor+0x586/0xcc0 fs/splice.c:1096
do_splice_direct_actor fs/splice.c:1230 [inline]
do_splice_direct+0x19b/0x2a0 fs/splice.c:1256
do_sendfile+0x540/0x7e0 fs/read_write.c:1371
__do_sys_sendfile64 fs/read_write.c:1432 [inline]
__se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1418
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f957c1a88f9
RSP: 002b:00007f957b406028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f957c3d5fa0 RCX: 00007f957c1a88f9
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003
RBP: 00007f957c23b984 R08: 0000000000000000 R09: 0000000000000000
R10: 000400000000003f R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f957c3d5fa0 R15: 00007ffc4fde19e8
Showing all locks held in the system:
locks held by khungtaskd/39: 1, last CPU#0:
#0: ffffffff8f3c1680 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#0: ffffffff8f3c1680 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8f3c1680 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871
locks held by getty/5360: 2, on CPU#0:
#0: ffff88803744c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900044db2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
locks held by syz.0.16/6454: 1, on CPU#0:
#0: ffff888028e79688 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
#0: ffff888028e79688 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_write_iter+0x4f7/0x700 block/fops.c:783
locks held by syz.0.16/6455: 3, last CPU#1:
#0: ffff888028e79688 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
#0: ffff888028e79688 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x263/0x550 block/fops.c:890
#1: ffff888028e79858 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:1079 [inline]
#1: ffff888028e79858 (mapping.invalidate_lock){++++}-{4:4}, at: blkdev_fallocate+0x294/0x550 block/fops.c:891
#2: ffff888028b0b2d8 (&q->q_usage_counter(io)#66){++++}-{0:0}, at: __submit_bio_noacct_mq block/blk-core.c:757 [inline]
#2: ffff888028b0b2d8 (&q->q_usage_counter(io)#66){++++}-{0:0}, at: submit_bio_noacct_nocheck+0x358/0xb10 block/blk-core.c:791
locks held by syz.1.1908/10617: 2, last CPU#0:
#0: ffff8880265db7b8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:530 [inline]
#0: ffff8880265db7b8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x2d8/0x9f0 mm/mmap.c:1323
#1: ffffffff8f3c1680 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
#1: ffffffff8f3c1680 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8f3c1680 (rcu_read_lock){....}-{1:3}, at: __rt_spin_trylock kernel/locking/spinlock_rt.c:127 [inline]
#1: ffffffff8f3c1680 (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x10c/0x2b0 kernel/locking/spinlock_rt.c:135
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123
nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66
trigger_all_cpu_backtrace include/linux/nmi.h:164 [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:353 [inline]
watchdog+0xfd2/0x1030 kernel/hung_task.c:561
kthread+0x38b/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 57 Comm: kworker/1:1H Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:deref_stack_reg+0xa/0x220 arch/x86/kernel/unwind_orc.c:418
Code: c1 00 48 8b 4c 24 18 e9 f2 fe ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 <48> 83 ec 10 48 89 d3 49 89 f0 49 89 ff 48 be 00 00 00 00 00 fc ff
RSP: 0018:ffffc9000123ef68 EFLAGS: 00000283
RAX: fffffffffffffff0 RBX: ffffffff916a0c38 RCX: 0000000000000000
RDX: ffffc9000123f088 RSI: ffffc9000123f180 RDI: ffffc9000123f048
RBP: 1ffffffff22d4187 R08: ffffc9000123f180 R09: 0000000000000000
R10: ffffc9000123f098 R11: fffff52000247e15 R12: dffffc0000000000
R13: ffffffff916a0c39 R14: ffffc9000123f048 R15: ffffc9000123f090
FS: 0000000000000000(0000) GS:ffff88812484d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3125ffff CR3: 000000003d180000 CR4: 00000000003526f0
Call Trace:
unwind_next_frame+0x19bd/0x2550 arch/x86/kernel/unwind_orc.c:-1
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3287 [inline]
call_rcu+0x86/0x300 kernel/rcu/tree.c:3395
slab_free_hook mm/slub.c:2744 [inline]
slab_free mm/slub.c:6630 [inline]
kmem_cache_free+0x539/0x6d0 mm/slub.c:6757
mempool_free+0xf5/0x140 mm/mempool.c:717
__bio_chain_endio block/bio.c:349 [inline]
bio_endio+0x3f/0xac0 block/bio.c:1835
blk_update_request+0x57b/0xe50 block/blk-mq.c:1029
blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1160
nullb_complete_cmd drivers/block/null_blk/main.c:1420 [inline]
null_handle_cmd drivers/block/null_blk/main.c:1472 [inline]
null_queue_rq+0xc25/0xe70 drivers/block/null_blk/main.c:1711
blk_mq_dispatch_rq_list+0x4af/0x1a00 block/blk-mq.c:2130
__blk_mq_sched_dispatch_requests+0x13b7/0x1590 block/blk-mq-sched.c:313
blk_mq_sched_dispatch_requests+0xda/0x1a0 block/blk-mq-sched.c:329
blk_mq_run_work_fn+0x22c/0x2f0 block/blk-mq.c:2545
process_one_work kernel/workqueue.c:3495 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
kthread+0x38b/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245