From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f77.google.com (mail-ot1-f77.google.com [209.85.210.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 92974C2EA for ; Tue, 25 Aug 2026 00:03:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787616217; cv=none; b=jS9tjpSCYQ7OorO/kggEpoQnlYUHxwraeEln27NHRWRDbdKmK5NBem66aO8elxymUZYGxAULU7a9eSC7SPa0yYBHTZ2dtVlkqQB2XmnOELwF0a2ge9xmhMGIE3kwMaChZzvZnGNSq9ti5nXHcneUPgKA8EithMlCwQJeuh5W7vg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787616217; c=relaxed/simple; bh=hKxVrS7dbUlGS6mZuFl3qfu2ArhnJaQegckvWWa+zcQ=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=HRlsfTU6R0KYyVN6xFmNOxK9V2QbiHx8A1QlIewgFqAN2vk7/lPNrmzYm9TkZSNCm79HJw6v7/l5kXaK+L7NRWwhDQh6GeFbkOzWTgXOEhIdtJtudl53yUOvQd61hgD0lz4AQji9U5j4H8U0n41WkbuY/uIzsoCcWmixcJI4EeM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.210.77 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-ot1-f77.google.com with SMTP id 46e09a7af769-7e9e2db9914so480984a34.1 for ; Mon, 24 Aug 2026 17:03:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1787616214; x=1788221014; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=t6BcztwYJfjwIkYQdxuxB7emwamKguryRvqZBYyDjp0=; b=nV/1bN3IsJ5k9lnV3cZq1yNDYn/Tho1l8/Y4xWxDmSLjZlDkh+unxaLQWTZ7G035ea bnIdTeLxGq8qukcNcPPus+ajvtXksrQfaFn4+lqh5CxGCV0IfXNCmGSqcONFAtKPx7zt 7iAqRMJcHlZ37dhQnhnGGlzp0q9JLXVRzUVdO69hpdE3R6euplfB2oKP/85ErASRjY9V ndRpS3YsUQqlSrgwxAq5yeVNGzOzgveYixWx69GW81X/rgGSnD8D5h4RvEM8MuEDy5nz BZEIIhiHgm2gIBoFVq6TSs5Mwn0jRsn9t4hbrBnwflkz1ucYLEq7AHO/B/eYYVeB7ZKp Ol6w== X-Forwarded-Encrypted: i=1; AHgh+RrF/U7OlHQphu9uI9S0pQ9jpSmn5WRjdnhgX+EwBOausnXvuaW4o0UyVgw1m1fMABi0OyGAPBaNJPLr34E=@vger.kernel.org X-Gm-Message-State: AFuF++lkV/mxtDU/ceN7myEXIs2tk7Lt73zIgPm/zIoLbzgfCtWdsFlK 29Ygz2Ppj3Wdxi1SV6m8pj09diqbDQei2vC4l7LFATGkkYnpeqBq7/xObogcc0EVY2+RPid6zKl 9lphZkZRuksGfltddlGMiPGDvqs5E+P/5UENlTIBdXadaNOrELhFiseaYCY4= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:6ae2:b0:6b1:3d06:ae0b with SMTP id 006d021491bc7-6b18fa81702mr2082389eaf.2.1787616214173; Mon, 24 Aug 2026 17:03:34 -0700 (PDT) Date: Mon, 24 Aug 2026 17:03:34 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a8cdbd6.dbb3a75c.7844.0012.GAE@google.com> Subject: [syzbot] [kernel?] INFO: task hung in mmc_stop_host From: syzbot To: anna-maria@linutronix.de, frederic@kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tglx@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 388b607d107c Merge tag 'efi-next-for-v7.3' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1519c625580000 kernel config: https://syzkaller.appspot.com/x/.config?x=335632b21d0ce540 dashboard link: https://syzkaller.appspot.com/bug?extid=d0688023306aea3aefdc compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/20c420e92df0/disk-388b607d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/82f836a86dcc/vmlinux-388b607d.xz kernel image: https://storage.googleapis.com/syzbot-assets/c3b00ac47be8/bzImage-388b607d.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d0688023306aea3aefdc@syzkaller.appspotmail.com INFO: task kworker/0:4:1939 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:4 state:D stack:21280 pid:1939 tgid:1939 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17d4/0x5820 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+0xa63/0xca0 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:458 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+0x444/0x560 drivers/base/bus.c:664 device_del+0x524/0x8f0 drivers/base/core.c:3965 usb_disable_device+0x3d4/0x8d0 drivers/usb/core/message.c:1478 usb_disconnect+0x346/0x9a0 drivers/usb/core/hub.c:2345 hub_port_connect drivers/usb/core/hub.c:5415 [inline] hub_port_connect_change drivers/usb/core/hub.c:5715 [inline] port_event drivers/usb/core/hub.c:5879 [inline] hub_event+0x1bbb/0x4d30 drivers/usb/core/hub.c:5961 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/0x480 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 INFO: task kworker/0:8:1944 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:8 state:D stack:21512 pid:1944 tgid:1944 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_freezable mmc_rescan Call Trace: context_switch kernel/sched/core.c:5520 [inline] __schedule+0x17d4/0x5820 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+0x6eb/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/0x480 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 Showing all locks held in the system: locks held by khungtaskd/31: 1, last CPU#1: #0: ffffffff8ed5a420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ed5a420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8ed5a420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6793 locks held by getty/5366: 2, on CPU#1: #0: ffff8880364560a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by kworker/0:4/1939: 5, on CPU#0: #0: ffff88801eaa2d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801eaa2d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801eaa2d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff88801eaa2d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc90003e7fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90003e7fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90003e7fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc90003e7fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #2: ffff8880265631d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff8880265631d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4d30 drivers/usb/core/hub.c:5907 #3: ffff8880677ae1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff8880677ae1d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xfc/0x9a0 drivers/usb/core/hub.c:2336 #4: ffff888053cc71a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff888053cc71a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff888053cc71a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1369 locks held by kworker/0:8/1944: 2, on CPU#0: #0: ffff88801b06a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801b06a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801b06a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #0: ffff88801b06a140 ((wq_completion)events_freezable){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 #1: ffffc90003b4fc40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90003b4fc40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90003b4fc40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3352 [inline] #1: ffffc90003b4fc40 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3470 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x480 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: 1002 Comm: kworker/u8:6 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:mark_usage kernel/locking/lockdep.c:4636 [inline] RIP: 0010:__lock_acquire+0x5d5/0x2cf0 kernel/locking/lockdep.c:5207 Code: fe e8 4f 88 76 03 e9 69 ff ff ff 44 89 e0 38 44 24 10 76 16 e8 5c 86 35 03 85 c0 74 0d 83 3d 95 3d d7 0e 00 0f 84 93 07 00 00 <85> ed 0f 84 96 00 00 00 41 8b 45 20 66 85 c0 78 7e 65 8b 0d af 51 RSP: 0018:ffffc900051575b8 EFLAGS: 00000046 RAX: 0000000000000004 RBX: ffff888028192ba8 RCX: 0000000000000004 RDX: 0000000000000004 RSI: 0000000000000005 RDI: 0000000000000000 RBP: 0000000000000001 R08: ffffffff816ac8cf R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8ebfd3a0 R12: 0000000000000004 R13: ffff888028192b88 R14: ffff888028191f40 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888124df4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c359880 CR3: 000000000eb46000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5886 __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 arch_jump_label_transform_queue+0x5f/0x110 arch/x86/kernel/jump_label.c:136 __jump_label_update+0x189/0x370 kernel/jump_label.c:513 static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1fe/0x290 mm/kfence/core.c:918 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/0x480 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 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup