Re: [syzbot] [kernel?] INFO: task hung in uevent_show (2)

[syzbot <syzbot+592e2ab8775dbe0bf09a@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in usbdev_ioctl

INFO: task syz.1.17:6837 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc4-syzkaller-00314-gb4b4dbfa96de-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.17        state:D stack:24088 pid:6837  tgid:6836  ppid:6635   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x65d/0xc70 kernel/locking/mutex.c:747
 device_lock include/linux/device.h:884 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2611 [inline]
 usbdev_ioctl+0x140/0x20c0 drivers/usb/core/devio.c:2827
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fddcf58d169
RSP: 002b:00007fddd03af038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fddcf7a5fa0 RCX: 00007fddcf58d169
RDX: 0000000000000000 RSI: 0000000041045508 RDI: 0000000000000003
RBP: 00007fddcf60e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fddcf7a5fa0 R15: 00007fff1a55f668
 </TASK>
INFO: task syz.1.17:6837 is blocked on a mutex likely owned by task kworker/1:4:5945.
task:kworker/1:4     state:S stack:22472 pid:5945  tgid:5945  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x3d7/0x710 kernel/sched/completion.c:116
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion_interruptible+0x1f/0x40 kernel/sched/completion.c:216
 send_packet+0x63b/0xae0 drivers/media/rc/imon.c:649
 imon_init_rdev drivers/media/rc/imon.c:1990 [inline]
 imon_init_intf0 drivers/media/rc/imon.c:2279 [inline]
 imon_probe+0x1f7e/0x3410 drivers/media/rc/imon.c:2436
 usb_probe_interface+0x644/0xbc0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x26d/0x9a0 drivers/base/dd.c:657
 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799
 driver_probe_device+0x4f/0x430 drivers/base/dd.c:829
 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:957
 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462
 __device_attach+0x2b8/0x400 drivers/base/dd.c:1029
 bus_probe_device+0x185/0x260 drivers/base/bus.c:537
 device_add+0x7b6/0xb50 drivers/base/core.c:3692
 usb_set_configuration+0x1a87/0x20e0 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x390 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x26d/0x9a0 drivers/base/dd.c:657
 __driver_probe_device+0x18c/0x2f0 drivers/base/dd.c:799
 driver_probe_device+0x4f/0x430 drivers/base/dd.c:829
 __device_attach_driver+0x2ce/0x530 drivers/base/dd.c:957
 bus_for_each_drv+0x24e/0x2e0 drivers/base/bus.c:462
 __device_attach+0x2b8/0x400 drivers/base/dd.c:1029
 bus_probe_device+0x185/0x260 drivers/base/bus.c:537


Tested on:

commit:         b4b4dbfa media: stk1160: use usb_alloc_noncoherent/usb..
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=170c9bd4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b49da22b2184ad70
dashboard link: https://syzkaller.appspot.com/bug?extid=592e2ab8775dbe0bf09a
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
patch:          https://syzkaller.appspot.com/x/patch.diff?x=152f5a8c580000