syzbot
INFO: task hung in sdio_reset
Status:
upstream: reported on 2026/10/01 10:34
Reported-by: syzbot+054bd72f6afca9bdf3e4@syzkaller.appspotmail.com
First crash: 11d, last: 11d
Sample crash report:
INFO: task kworker/0:0:7 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:0 state:D stack:22832 pid: 7 ppid: 2 flags:0x00004000
Workqueue: events_freezable mmc_rescan
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093
do_wait_for_common+0x295/0x460 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
mmc_wait_for_req_done+0x33/0x460 drivers/mmc/core/core.c:403
mmc_wait_for_cmd+0x174/0x280 drivers/mmc/core/core.c:639
mmc_io_rw_direct_host drivers/mmc/core/sdio_ops.c:83 [inline]
sdio_reset+0x20e/0x3b0 drivers/mmc/core/sdio_ops.c:215
mmc_rescan_try_freq drivers/mmc/core/core.c:2073 [inline]
mmc_rescan+0x65f/0xe30 drivers/mmc/core/core.c:2256
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
INFO: task kworker/0:2:1108 blocked for more than 146 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:2 state:D stack:22736 pid: 1108 ppid: 2 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0xbd/0x2d0 kernel/time/timer.c:2093
do_wait_for_common+0x295/0x460 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
__flush_work+0x15a/0x210 kernel/workqueue.c:3094
__cancel_work_timer+0x3f4/0x560 kernel/workqueue.c:3181
__mmc_stop_host drivers/mmc/core/core.c:2294 [inline]
mmc_stop_host+0xd5/0x460 drivers/mmc/core/core.c:2299
mmc_remove_host+0x11/0x60 drivers/mmc/core/host.c:642
vub300_disconnect+0x14b/0x2e0 drivers/mmc/host/vub300.c:2388
usb_unbind_interface+0x203/0x870 drivers/usb/core/driver.c:458
__device_release_driver drivers/base/dd.c:1249 [inline]
device_release_driver_internal+0x487/0x710 drivers/base/dd.c:1282
bus_remove_device+0x2dd/0x400 drivers/base/bus.c:531
device_del+0x63f/0xa80 drivers/base/core.c:3615
usb_disable_device+0x3e7/0x8a0 drivers/usb/core/message.c:1472
usb_disconnect+0x33c/0x8a0 drivers/usb/core/hub.c:2292
hub_port_connect drivers/usb/core/hub.c:5346 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5642 [inline]
port_event drivers/usb/core/hub.c:5804 [inline]
hub_event+0x1d64/0x5260 drivers/usb/core/hub.c:5886
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Showing all locks held in the system:
2 locks held by kworker/0:0/7:
#0: ffff888016c71538 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc90000cc7d00 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
1 lock held by khungtaskd/27:
#0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
5 locks held by kworker/0:2/1108:
#0: ffff88814179d938 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc90004777d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
#2: ffff888147ce5220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#2: ffff888147ce5220 (&dev->mutex){....}-{3:3}, at: hub_event+0x178/0x5260 drivers/usb/core/hub.c:5832
#3: ffff88807d3fe220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#3: ffff88807d3fe220 (&dev->mutex){....}-{3:3}, at: usb_disconnect+0xf8/0x8a0 drivers/usb/core/hub.c:2283
#4: ffff88807b4341a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:809 [inline]
#4: ffff88807b4341a8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1064 [inline]
#4: ffff88807b4341a8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xa1/0x710 drivers/base/dd.c:1279
2 locks held by getty/3942:
#0: ffff88814cb01098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
2 locks held by kworker/0:10/5296:
#0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1
#1: ffffc900030efd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285
2 locks held by syz.5.278/5772:
#0: ffffffff8d44d548 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:699 [inline]
#0: ffffffff8d44d548 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3d/0x1b0 drivers/net/tun.c:3454
#1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#1: ffffffff8c3239e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845
1 lock held by syz.8.279/5773:
#0: ffffffff8d44d548 (rtnl_mutex){+.+.}-{3:3}, at: netdev_run_todo+0x8dd/0xac0 net/core/dev.c:10722
1 lock held by rm/5811:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
<TASK>
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe1b/0xe60 kernel/hung_task.c:369
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
* Struck through repros no longer work on HEAD.