INFO: task syz.3.321:7031 blocked for more than 144 seconds.
Not tainted 6.15.0-syzkaller-10769-g7d4e49a77d99 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.321 state:D stack:28504 pid:7031 tgid:7030 ppid:5811 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5392 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6781
__schedule_loop kernel/sched/core.c:6859 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6874
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6931
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x6c7/0xb90 kernel/locking/mutex.c:747
nbd_start_device_ioctl drivers/block/nbd.c:1542 [inline]
__nbd_ioctl drivers/block/nbd.c:1602 [inline]
nbd_ioctl+0x30a/0xda0 drivers/block/nbd.c:1642
blkdev_ioctl+0x274/0x6d0 block/ioctl.c:704
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c1dd8e969
RSP: 002b:00007f5c1ebdc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5c1dfb5fa0 RCX: 00007f5c1dd8e969
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000004
RBP: 00007f5c1de10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5c1dfb5fa0 R15: 00007ffd98cf6148
INFO: task syz.3.321:7034 blocked for more than 144 seconds.
Not tainted 6.15.0-syzkaller-10769-g7d4e49a77d99 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.321 state:D stack:28888 pid:7034 tgid:7030 ppid:5811 task_flags:0x480140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5392 [inline]
__schedule+0x116a/0x5de0 kernel/sched/core.c:6781
__schedule_loop kernel/sched/core.c:6859 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6874
blk_mq_freeze_queue_wait+0x143/0x1b0 block/blk-mq.c:190
blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
queue_limits_commit_update_frozen+0x93/0x110 block/blk-settings.c:482
nbd_set_size+0x4e7/0x730 drivers/block/nbd.c:374
__nbd_ioctl drivers/block/nbd.c:1593 [inline]
nbd_ioctl+0xd34/0xda0 drivers/block/nbd.c:1642
blkdev_ioctl+0x274/0x6d0 block/ioctl.c:704
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5c1dd8e969
RSP: 002b:00007f5c1ebbb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5c1dfb6080 RCX: 00007f5c1dd8e969
RDX: 0000000000000582 RSI: 000000000000ab07 RDI: 0000000000000004
RBP: 00007f5c1de10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f5c1dfb6080 R15: 00007ffd98cf6148
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e5c4d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e5c4d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e5c4d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
2 locks held by kworker/u8:8/4589:
#0: ffff88814046a948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000f657d10 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
2 locks held by getty/5578:
#0: ffff8880327090a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
5 locks held by kworker/0:4/5864:
#0: ffff888140eca548 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000473fd10 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff8881447be198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#2: ffff8881447be198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fa0 drivers/usb/core/hub.c:5859
#3: ffff8880310e7198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#3: ffff8880310e7198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
#4: ffff888076b7c160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline]
#4: ffff888076b7c160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1004
1 lock held by udevd/6322:
#0: ffff888026b0b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945
1 lock held by syz.3.321/7031:
#0: ffff888026b10a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_start_device_ioctl drivers/block/nbd.c:1542 [inline]
#0: ffff888026b10a30 (&nbd->config_lock){+.+.}-{4:4}, at: __nbd_ioctl drivers/block/nbd.c:1602 [inline]
#0: ffff888026b10a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x30a/0xda0 drivers/block/nbd.c:1642
4 locks held by syz.3.321/7034:
#0: ffff888026b10a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x150/0xda0 drivers/block/nbd.c:1635
#1: ffff888141b710c8 (&q->limits_lock){+.+.}-{4:4}, at: queue_limits_start_update include/linux/blkdev.h:1002 [inline]
#1: ffff888141b710c8 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x2c3/0x730 drivers/block/nbd.c:354
#2: ffff888141b70a70 (&q->q_usage_counter(io)#52){++++}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 block/blk-mq.c:205
#3: ffff888141b70aa8 (&q->q_usage_counter(queue)#4){+.+.}-{0:0}, at: blk_mq_freeze_queue_nomemsave+0x15/0x20 block/blk-mq.c:205
2 locks held by syz.5.977/9282:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-syzkaller-10769-g7d4e49a77d99 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
watchdog+0xf70/0x12c0 kernel/hung_task.c:470
kthread+0x3c5/0x780 kernel/kthread.c:464
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
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: 9282 Comm: syz.5.977 Not tainted 6.15.0-syzkaller-10769-g7d4e49a77d99 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x71/0xc0 kernel/rcu/tree.c:745
Code: a0 5d f1 8d 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 <8b> 03 c1 e8 02 83 e0 01 65 ff 0d 90 65 2a 12 74 07 5b 5d c3 cc cc
RSP: 0018:ffffc9001cb86f30 EFLAGS: 00000246
RAX: 0000000000000003 RBX: ffff8880b85331e8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8c154460 RDI: ffffffff8df15da8
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000013be8 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888124865000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f062c380178 CR3: 000000001f2b6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x2cd/0x350 kernel/locking/lockdep.c:5834
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1248 [inline]
free_unref_folios+0xa65/0x1800 mm/page_alloc.c:2763
folios_put_refs+0x56f/0x740 mm/swap.c:992
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x58f/0x1150 mm/shmem.c:1125
shmem_truncate_range mm/shmem.c:1237 [inline]
shmem_evict_inode+0x3a1/0xbe0 mm/shmem.c:1365
evict+0x3e3/0x920 fs/inode.c:810
iput_final fs/inode.c:1898 [inline]
iput fs/inode.c:1924 [inline]
iput+0x521/0x880 fs/inode.c:1910
dentry_unlink_inode+0x29c/0x480 fs/dcache.c:466
__dentry_kill+0x1d0/0x600 fs/dcache.c:669
dput.part.0+0x4b1/0x9b0 fs/dcache.c:911
dput+0x1f/0x30 fs/dcache.c:901
__fput+0x51c/0xb70 fs/file_table.c:473
task_work_run+0x14d/0x240 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x864/0x2bd0 kernel/exit.c:955
do_group_exit+0xd3/0x2a0 kernel/exit.c:1104
get_signal+0x2673/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
irqentry_exit_to_user_mode+0x12a/0x270 kernel/entry/common.c:184
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fe4fcb8e969
Code: Unable to access opcode bytes at 0x7fe4fcb8e93f.
RSP: 002b:00007fe4fdad2fe8 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 00007fe4fcdb5fa0 RCX: 00007fe4fcb8e969
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000062000200
RBP: 00007fe4fcc10ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe4fcdb5fa0 R15: 00007ffff96f4188