Hello, syzbot found the following issue on: HEAD commit: ce9ecca0238b Linux 6.6-rc2 git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing console output: https://syzkaller.appspot.com/x/log.txt?x=15c0df5a680000 kernel config: https://syzkaller.appspot.com/x/.config?x=59eae8406319284a dashboard link: https://syzkaller.appspot.com/bug?extid=fe9e847f8a1d979468f2 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/7a503493dab8/disk-ce9ecca0.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/0265acc85204/vmlinux-ce9ecca0.xz kernel image: https://storage.googleapis.com/syzbot-assets/c4861e26a08d/bzImage-ce9ecca0.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+fe9e847f8a1d979468f2@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task kworker/0:2:28429 blocked for more than 143 seconds. Not tainted 6.6.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:2 state:D stack:22784 pid:28429 ppid:2 flags:0x00004000 Workqueue: events console_callback Call Trace: <TASK> context_switch kernel/sched/core.c:5382 [inline] __schedule+0xc79/0x30a0 kernel/sched/core.c:6695 schedule+0xe7/0x1b0 kernel/sched/core.c:6771 schedule_timeout+0x278/0x2c0 kernel/time/timer.c:2143 ___down_common kernel/locking/semaphore.c:225 [inline] __down_common+0x327/0x6c0 kernel/locking/semaphore.c:246 down+0x74/0xa0 kernel/locking/semaphore.c:63 console_lock+0x96/0x150 kernel/printk/printk.c:2652 console_callback+0x63/0x4c0 drivers/tty/vt/vt.c:2933 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 </TASK> Showing all locks held in the system: 2 locks held by kworker/u4:0/11: 1 lock held by khungtaskd/29: #0: ffffffff87eac820 (rcu_read_lock ){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:303 [inline] ){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:749 [inline] ){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6613 2 locks held by getty/2443: #0: ffff88810c3020a0 ( &tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc5/0x1480 drivers/tty/n_tty.c:2206 3 locks held by kworker/1:0/12460: #0: ffff88810aa6d138 ((wq_completion)usb_hub_wq ){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc90002e6fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 #2: ffff88810634e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #2: ffff88810634e190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f30 drivers/usb/core/hub.c:5768 3 locks held by kworker/0:1/14506: 2 locks held by kworker/0:2/28429: #0: ffff888100070d38 ((wq_completion)events){+.+.}-{0:0} , at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc9000ee27d80 (console_work){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 6 locks held by kworker/1:10/31385: #0: ffff88810aa6d138 ( (wq_completion)usb_hub_wq){+.+.}-{0:0} , at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc90010b4fd80 ( (work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 #2: ffff88810676e190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #2: ffff88810676e190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f30 drivers/usb/core/hub.c:5768 #3: ffff888106779500 (&port_dev->status_lock){+.+.}-{3:3} , at: usb_lock_port drivers/usb/core/hub.c:3138 [inline] , at: hub_port_connect drivers/usb/core/hub.c:5337 [inline] , at: hub_port_connect_change drivers/usb/core/hub.c:5580 [inline] , at: port_event drivers/usb/core/hub.c:5740 [inline] , at: hub_event+0x28b4/0x4f30 drivers/usb/core/hub.c:5822 #4: ffff888103fa3d68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5338 [inline] (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5580 [inline] (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5740 [inline] (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x28da/0x4f30 drivers/usb/core/hub.c:5822 #5: ffff8881f673b558 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:558 [inline] #5: ffff8881f673b558 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1372 [inline] #5: ffff8881f673b558 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1681 [inline] #5: ffff8881f673b558 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x290/0x30a0 kernel/sched/core.c:6612 5 locks held by kworker/0:12/963: 3 locks held by kworker/0:13/972: 4 locks held by kworker/0:10/3172: #0: ffff88810aa6d138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x787/0x15c0 kernel/workqueue.c:2605 #1: ffffc9000f70fd80 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7e9/0x15c0 kernel/workqueue.c:2606 #2: ffff888106366190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline] #2: ffff888106366190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1be/0x4f30 drivers/usb/core/hub.c:5768 #3: ffff88811b843190 (&dev->mutex){....}-{3:3} , at: device_lock include/linux/device.h:992 [inline] , at: usb_remote_wakeup+0x21/0xe0 drivers/usb/core/hub.c:3772 5 locks held by syz-executor.5/4757: 1 lock held by syz-executor.4/4778: 1 lock held by syz-executor.0/4781: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x277/0x380 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x26c/0x2d0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf87/0x1210 kernel/hung_task.c:379 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 </TASK> Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6142 Comm: kworker/1:8 Not tainted 6.6.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/04/2023 Workqueue: events legacy_dvb_usb_read_remote_control RIP: 0010:check_region_inline mm/kasan/generic.c:167 [inline] RIP: 0010:kasan_check_range+0x14c/0x190 mm/kasan/generic.c:187 Code: c0 01 49 89 d3 48 39 d0 74 11 80 38 00 74 ef 4d 8d 1c 2c 48 85 c0 48 89 c2 75 97 48 89 da 4c 89 d8 4c 29 da e9 30 ff ff ff 5b <b8> 01 00 00 00 5d 41 5c c3 b8 01 00 00 00 c3 48 29 c3 48 89 da 49 RSP: 0018:ffffc9000d7df670 EFLAGS: 00000046 RAX: fffffbfff16de139 RBX: 000000000000000e RCX: ffffffff812e172f RDX: fffffbfff16de139 RSI: 0000000000000008 RDI: ffffffff8b6f09c0 RBP: fffffbfff16de138 R08: 0000000000000000 R09: fffffbfff16de138 R10: ffffffff8b6f09c7 R11: 205d323431365420 R12: ffff888115b68b42 R13: ffff888115b68b20 R14: 00000000373b5825 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881f6700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f72ede41070 CR3: 000000013ea4b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] hlock_class kernel/locking/lockdep.c:228 [inline] __lock_acquire+0xc8f/0x5de0 kernel/locking/lockdep.c:5133 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 console_lock_spinning_enable kernel/printk/printk.c:1858 [inline] console_emit_next_record kernel/printk/printk.c:2904 [inline] console_flush_all+0x4c1/0xfb0 kernel/printk/printk.c:2966 console_unlock+0x10c/0x260 kernel/printk/printk.c:3035 vprintk_emit+0x17f/0x5f0 kernel/printk/printk.c:2307 vprintk+0x7b/0x90 kernel/printk/printk_safe.c:45 _printk+0xc8/0x100 kernel/printk/printk.c:2332 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline] m920x_rc_query+0x496/0x760 drivers/media/usb/dvb-usb/m920x.c:193 legacy_dvb_usb_read_remote_control+0x107/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 </TASK> --- 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@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the bug is already fixed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
