INFO: task hung in mmc_stop_host

Status: upstream: reported on 2026/08/25 00:03
Subsystems: kernel
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+d0688023306aea3aefdc@syzkaller.appspotmail.com
First crash: 26d, last: 37m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
ac8ad14a assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ✅ INFO: task hung in mmc_stop_host 2026/08/09 09:07 2026/08/09 09:07 2026/08/09 09:11 5d63f80b
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] INFO: task hung in mmc_stop_host 0 (1) 2026/08/25 00:03
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in mmc_stop_host 1 1 22h09m 22h08m 0/3 upstream: reported on 2026/08/30 19:05
linux-6.6 INFO: task hung in mmc_stop_host 1 1 16d 16d 0/2 upstream: reported on 2026/08/14 22:00

Sample crash report:
INFO: task kworker/1:3:5318 blocked for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:3     state:D stack:20192 pid:5318  tgid:5
task:kworker/1:3     state:D stack:20192 pid:5318  tgid:5318  ppid:2      task_flags:0x4288060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153
 __flush_work+0x9c2/0xd70 kernel/workqueue.c:4439
 __cancel_work_sync+0xbf/0x110 kernel/workqueue.c:4559
 __mmc_stop_host drivers/mmc/core/core.c:2368 [inline]
 mmc_stop_host+0xd9/0x460 drivers/mmc/core/core.c:2373
 mmc_remove_host+0x15/0x60 drivers/mmc/core/host.c:681
 vub300_disconnect+0x154/0x2f0 drivers/mmc/host/vub300.c:2387
 usb_unbind_interface+0x295/0x9f0 drivers/usb/core/driver.c:461
 device_remove drivers/base/dd.c:618 [inline]
 __device_release_driver drivers/base/dd.c:1349 [inline]
 device_release_driver_internal+0x4f5/0x880 drivers/base/dd.c:1372
 bus_remove_device+0x449/0x560 drivers/base/bus.c:664
 device_del+0x528/0x8f0 drivers/base/core.c:3965
 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478
 usb_disconnect+0x32d/0x990 drivers/usb/core/hub.c:2350
 hub_port_connect drivers/usb/core/hub.c:5420 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5720 [inline]
 port_event drivers/usb/core/hub.c:5884 [inline]
 hub_event+0x1bb7/0x4cf0 drivers/usb/core/hub.c:5966
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 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
 </TASK>
INFO: task kworker/1:0:11118 blocked for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0     state:D stack:20608 pid:11118 tgid:11118 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_freezable mmc_rescan
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x16d9/0x5700 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_timeout+0xc0/0x2c0 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:100 [inline]
 __wait_for_common kernel/sched/completion.c:121 [inline]
 wait_for_common kernel/sched/completion.c:132 [inline]
 wait_for_completion+0x2ca/0x5e0 kernel/sched/completion.c:153
 mmc_wait_for_req_done+0x37/0x490 drivers/mmc/core/core.c:408
 mmc_wait_for_cmd+0x183/0x2a0 drivers/mmc/core/core.c:645
 mmc_io_rw_direct_host drivers/mmc/core/sdio_ops.c:83 [inline]
 sdio_reset+0xf4/0x3a0 drivers/mmc/core/sdio_ops.c:209
 mmc_rescan_try_freq drivers/mmc/core/core.c:2121 [inline]
 mmc_rescan+0x6ee/0x1040 drivers/mmc/core/core.c:2316
 process_one_work kernel/workqueue.c:3387 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
 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
 </TASK>

Showing all locks held in the system:
locks held by khungtaskd/38: 1, last CPU#0:
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6837
locks held by kworker/1:3/5318: 5, on CPU#1:
 #0: ffff8880222bad38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff8880222bad38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff8880222bad38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #0: ffff8880222bad38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #1: ffffc9000499fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000499fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000499fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #1: ffffc9000499fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #2: ffff88802a51e210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #2: ffff88802a51e210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5912
 #3: ffff888026a32210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #3: ffff888026a32210 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xe3/0x990 drivers/usb/core/hub.c:2341
 #4: ffff88803c7fb1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #4: ffff88803c7fb1d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline]
 #4: ffff88803c7fb1d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369
locks held by getty/5341: 2, on CPU#0:
 #0: ffff88803669e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900044c32e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/1:8/6268: 3, on CPU#1:
 #0: ffff88813ff26938 ((wq_completion)events_freezable){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88813ff26938 ((wq_completion)events_freezable){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88813ff26938 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #0: ffff88813ff26938 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #1: ffffc90006927c40 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90006927c40 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90006927c40 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #1: ffffc90006927c40 ((work_completion)(&hcd->wakeup_work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #2: ffff88802a64c210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline]
 #2: ffff88802a64c210 (&dev->mutex){....}-{4:4}, at: usb_remote_wakeup+0x23/0x120 drivers/usb/core/hub.c:3899
locks held by kworker/1:0/11118: 2, on CPU#1:
 #0: ffff88813ff26938 ((wq_completion)events_freezable){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff88813ff26938 ((wq_completion)events_freezable){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff88813ff26938 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #0: ffff88813ff26938 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
 #1: ffffc9000439fc40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc9000439fc40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc9000439fc40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline]
 #1: ffffc9000439fc40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470
locks held by syz-executor/12160: 3, last CPU#1:
 #0: ffffffff8e29eaf0 (dup_mmap_sem){.+.+}-{0:0}, at: dup_mm kernel/fork.c:1542 [inline]
 #0: ffffffff8e29eaf0 (dup_mmap_sem){.+.+}-{0:0}, at: copy_mm+0x10f/0x480 kernel/fork.c:1595
 #1: ffff888011933a30 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline]
 #1: ffff888011933a30 (&mm->mmap_lock){++++}-{4:4}, at: dup_mmap+0x18e/0x1d80 mm/mmap.c:1716
 #2: ffffffff99db6700 (&obj_hash[i].lock){-...}-{2:2}, at: debug_object_activate+0xa8/0x3b0 lib/debugobjects.c:873
locks held by syz-executor/12366: 2, last CPU#1:
 #0: ffff888025bb4510 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffff888033fa4670 (&sb->s_type->i_lock_key){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #1: ffff888033fa4670 (&sb->s_type->i_lock_key){+.+.}-{3:3}, at: filemap_remove_folio+0xdb/0x3a0 mm/filemap.c:255
locks held by syz-executor/12500: 1, last CPU#0:
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3d/0x420 kernel/softirq.c:186
locks held by syz.1.2754/17851: 4, last CPU#0:
 #0: ffff888025c60510 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1126 [inline]
 #0: ffff888025c60510 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x376c/0x4530 fs/coredump.c:1195
 #1: ffff888062abe2b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:609 [inline]
 #1: ffff888062abe2b0 (&mm->mmap_lock){++++}-{4:4}, at: dump_user_range+0x1c5/0x12c0 fs/coredump.c:1349
 #2: ffffe8ffffc4d070 (&acomp_ctx->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:853 [inline]
 #2: ffffe8ffffc4d070 (&acomp_ctx->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1422 [inline]
 #2: ffffe8ffffc4d070 (&acomp_ctx->mutex){+.+.}-{4:4}, at: zswap_store+0xcb7/0x2050 mm/zswap.c:1533
 #3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: is_bpf_text_address+0x26/0x2b0 kernel/bpf/core.c:749
locks held by syz.0.2873/18186: 1, last CPU#0:
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495
locks held by syz.1.2875/18201: 3, last CPU#0:
 #0: ffff888025c60510 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1126 [inline]
 #0: ffff888025c60510 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x376c/0x4530 fs/coredump.c:1195
 #1: ffff888060cb1290 (&sb->s_type->i_mutex_key#14){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff888060cb1290 (&sb->s_type->i_mutex_key#14){++++}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3430
 #2: ffff8880b8635380 (()){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #2: ffff8880b8635380 (()){+.+.}-{3:3}, at: folio_alloc_swap+0x33e/0x12c0 mm/swapfile.c:1767
locks held by syz.1.2875/18206: 3, last CPU#1:
 #0: ffff888025c60510 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1126 [inline]
 #0: ffff888025c60510 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x376c/0x4530 fs/coredump.c:1195
 #1: ffff88801195d610 (&sb->s_type->i_mutex_key#14){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #1: ffff88801195d610 (&sb->s_type->i_mutex_key#14){++++}-{4:4}, at: shmem_file_write_iter+0x82/0x120 mm/shmem.c:3430
 #2: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #2: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: shrink_slab_memcg mm/shrinker.c:522 [inline]
 #2: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: shrink_slab+0x1e9/0x1220 mm/shrinker.c:638
locks held by syz.3.2930/18372: 5, last CPU#1:
 #0: ffff8880741dc7b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:600 [inline]
 #0: ffff8880741dc7b0 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x1a4/0x9f0 mm/mmap.c:1299
 #1: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: __pte_offset_map+0x29/0x200 mm/pgtable-generic.c:290
 #2: ffff88802ac0f418 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
 #2: ffff88802ac0f418 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:404
 #3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 #3: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1e2/0x400 kernel/locking/spinlock_rt.c:57
 #4: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #4: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #4: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: page_table_check_clear+0x124/0x500 mm/page_table_check.c:77
locks held by syz.1.2929/18376: 1, last CPU#1:
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
 #0: ffffffff8e1c3ac0 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0x8f/0x2550 arch/x86/kernel/unwind_orc.c:495

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 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+0xfd7/0x1030 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17 Comm: pr/ttyS0 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:409
Code: e8 de fb 65 fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 7f aa d1 fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900001678b8 EFLAGS: 00000202
RAX: 1ffffffff33d2e00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff856078e0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99e97220 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125bd6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffd07f7d10 CR3: 00000001462cc000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000411
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:128 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
 wait_for_lsr+0x190/0x300 drivers/tty/serial/8250/8250_port.c:2013
 serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3270 [inline]
 __serial8250_console_fifo_write+0xd0/0x3f0 drivers/tty/serial/8250/8250_port.c:3345
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3378 [inline]
 __serial8250_console_write drivers/tty/serial/8250/8250_port.c:3429 [inline]
 serial8250_console_write+0xac5/0x1230 drivers/tty/serial/8250/8250_port.c:3493
 nbcon_emit_next_record+0xef5/0x1a90 kernel/printk/nbcon.c:-1
 nbcon_emit_one kernel/printk/nbcon.c:1157 [inline]
 nbcon_kthread_func+0x679/0x880 kernel/printk/nbcon.c:1271
 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
 </TASK>

Crashes (199):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/31 14:20 upstream cee9395acd80 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in mmc_stop_host
2026/08/30 09:24 upstream 08dbfad3f504 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in mmc_stop_host
2026/08/30 03:14 upstream 08dbfad3f504 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in mmc_stop_host
2026/08/29 16:02 upstream cf72cbb39da8 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in mmc_stop_host
2026/08/29 13:08 upstream cf72cbb39da8 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in mmc_stop_host
2026/08/29 03:52 upstream 1b78070aaef6 bcbc8ceb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in mmc_stop_host
2026/08/28 10:14 upstream 1b78070aaef6 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in mmc_stop_host
2026/08/28 08:05 upstream 1b78070aaef6 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in mmc_stop_host
2026/08/27 22:34 upstream 73e3f0710014 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in mmc_stop_host
2026/08/25 16:36 upstream 66498c75b4f8 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in mmc_stop_host
2026/08/23 19:26 upstream 388b607d107c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in mmc_stop_host
2026/08/20 23:38 upstream 9328b3b03bdc 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in mmc_stop_host
2026/08/18 08:16 upstream ff68e5f557f6 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in mmc_stop_host
2026/08/30 19:11 upstream a23cbb05744b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in mmc_stop_host
2026/08/29 00:45 upstream c20313e98b04 bcbc8ceb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in mmc_stop_host
2026/08/28 02:50 upstream 73e3f0710014 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in mmc_stop_host
2026/08/31 16:17 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing cee9395acd80 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/31 12:44 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing cee9395acd80 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/31 10:01 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/31 08:30 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/31 06:56 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/31 06:40 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/31 04:05 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/31 02:57 linux-next e30626823a40 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in mmc_stop_host
2026/08/31 01:19 linux-next e30626823a40 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in mmc_stop_host
2026/08/31 00:09 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/30 23:05 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/30 20:55 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/30 17:09 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/30 15:23 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/30 12:14 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/30 10:49 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/30 07:32 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/30 06:30 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/30 04:24 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/29 22:33 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/29 21:16 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/29 20:14 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/29 17:35 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/29 14:58 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/29 10:41 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/29 08:33 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/29 06:27 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/29 02:16 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/28 23:27 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/28 20:02 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/28 16:06 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/28 13:56 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/28 11:50 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/28 05:57 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/28 03:54 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/27 21:29 linux-next 3d83758432b5 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in mmc_stop_host
2026/08/27 20:16 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/27 18:43 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/27 15:51 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/27 14:51 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 45c13f3f9e3b 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in mmc_stop_host
2026/08/04 17:48 linux-next cc2b5f627e8c d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in mmc_stop_host
2026/08/17 18:00 https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux master 8d3ae59288f1 905244d6 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-arm32 INFO: task hung in mmc_stop_host
* Struck through repros no longer work on HEAD.