INFO: task syz-executor742:5666 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor742 state:D stack:28008 pid:5666  tgid:5666  ppid:5653   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7376
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7433
 rwsem_down_write_slowpath+0x4c2/0x12a0 kernel/locking/rwsem.c:1215
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0x1c0/0x1f0 kernel/locking/rwsem.c:1632
 inode_lock include/linux/fs.h:1024 [inline]
 blkdev_fallocate+0x24b/0x440 block/fops.c:889
 vfs_fallocate+0x576/0x10a0 fs/open.c:338
 ksys_fallocate fs/open.c:362 [inline]
 __do_sys_fallocate fs/open.c:367 [inline]
 __se_sys_fallocate fs/open.c:365 [inline]
 __x64_sys_fallocate+0xd5/0x140 fs/open.c:365
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9019c1fc49
RSP: 002b:00007ffd9c270ea8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f9019c1fc49
RDX: 0000000000000000 RSI: 0000000000000011 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000003
R10: 0000001000074000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffd9c270ef0 R14: 00007ffd9c270f30 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/32: 1, last CPU#0:
 #0: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871
locks held by kworker/1:1H/2259: 5, last CPU#1:
 #0: ffff8880222c3940 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371
 #1: ffffc900068afd08 ((work_completion)(&(&hctx->run_work)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372
 #2: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: blk_mq_run_work_fn+0x1c7/0x380 block/blk-mq.c:2544
 #3: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #3: ffffffff8fdec5a0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495
 #4: ffff8880b833bf60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2c/0x140 kernel/sched/core.c:677
locks held by getty/5366: 2, on CPU#1:
 #0: ffff888035a0e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000323b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211
locks held by syz-executor742/5665: 2, on CPU#0:
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:889
 #1: ffff88802596a080 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock include/linux/fs.h:1079 [inline]
 #1: ffff88802596a080 (mapping.invalidate_lock){++++}-{4:4}, at: blkdev_fallocate+0x273/0x440 block/fops.c:890
locks held by syz-executor742/5666: 1, on CPU#0:
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:889
locks held by syz-executor742/5673: 1, on CPU#1:
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:889
locks held by syz-executor742/5674: 1, on CPU#1:
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:889
locks held by syz-executor742/5681: 1, on CPU#0:
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff888025969ee8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_fallocate+0x24b/0x440 block/fops.c:889

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123
 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 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+0x141/0x190 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xcb1/0x1030 kernel/hung_task.c:561
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 2259 Comm: kworker/1:1H Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:114 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline]
RIP: 0010:kasan_check_range+0x71/0x1e0 mm/kasan/generic.c:200
Code: 37 ff 48 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 48 c1 ed 03 49 c1 e9 03 48 01 c5 49 01 c1 48 89 e8 49 8d 59 01 48 89 da <48> 29 ea 48 83 fa 10 0f 8e db 00 00 00 41 89 eb 41 83 e3 07 0f 85
RSP: 0018:ffffc900068af608 EFLAGS: 00000082
RAX: fffffbfff248ad0b RBX: fffffbfff248ad0c RCX: ffffffff81f10288
RDX: fffffbfff248ad0c RSI: 0000000000000008 RDI: ffffffff92456858
RBP: fffffbfff248ad0b R08: 0000000000000000 R09: fffffbfff248ad0b
R10: ffffffff9245685f R11: 000000000000763b R12: 0000000000000001
R13: 0000000000000200 R14: ffff8880b833d090 R15: ffff8880b833d028
FS:  0000000000000000(0000) GS:ffff888122a46000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9019c445c0 CR3: 0000000069999000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:82 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 cpumask_test_cpu include/linux/cpumask.h:650 [inline]
 cpu_online include/linux/cpumask.h:1232 [inline]
 call_rcu_core kernel/rcu/tree.c:3071 [inline]
 __call_rcu_common.constprop.0+0x388/0x9b0 kernel/rcu/tree.c:3205
 slab_free_hook mm/slub.c:2712 [inline]
 slab_free mm/slub.c:6509 [inline]
 kmem_cache_free+0x43b/0x6c0 mm/slub.c:6636
 mempool_free+0xde/0x130 mm/mempool.c:717
 bio_put_percpu_cache block/bio.c:831 [inline]
 bio_put+0x355/0x5b0 block/bio.c:850
 __bio_chain_endio block/bio.c:329 [inline]
 bio_endio+0x436/0x9c0 block/bio.c:1910
 blk_update_request+0x741/0x1380 block/blk-mq.c:1029
 blk_mq_end_request+0x57/0x420 block/blk-mq.c:1160
 blk_mq_complete_request block/blk-mq.c:1338 [inline]
 blk_mq_complete_request+0x8b/0xb0 block/blk-mq.c:1335
 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+0xb48/0xfb0 drivers/block/null_blk/main.c:1711
 blk_mq_dispatch_rq_list+0x428/0x1e60 block/blk-mq.c:2130
 __blk_mq_sched_dispatch_requests+0x67a/0x1620 block/blk-mq-sched.c:313
 blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
 blk_mq_run_work_fn+0x1fe/0x380 block/blk-mq.c:2544
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.101 msecs