maillist inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9KUFO

Reference: https://lore.kernel.org/all/20240412135256.1546051-1-zhengyejian1@huawei.com...

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Infinite log printing occurs during fuzz test:

rc rc1: DViCO FusionHDTV DVB-T USB (LGZ201) as ... ... dvb-usb: schedule remote query interval to 100 msecs. dvb-usb: DViCO FusionHDTV DVB-T USB (LGZ201) successfully initialized ... dvb-usb: bulk message failed: -22 (1/0) dvb-usb: bulk message failed: -22 (1/0) dvb-usb: bulk message failed: -22 (1/0) ... dvb-usb: bulk message failed: -22 (1/0)

Looking into the codes, there is a loop in dvb_usb_read_remote_control(), that is in rc_core_dvb_usb_remote_init() create a work that will call dvb_usb_read_remote_control(), and this work will reschedule itself at 'rc_interval' intervals to recursively call dvb_usb_read_remote_control(), see following code snippet:

rc_core_dvb_usb_remote_init() { ... INIT_DELAYED_WORK(&d->rc_query_work, dvb_usb_read_remote_control); schedule_delayed_work(&d->rc_query_work, msecs_to_jiffies(rc_interval)); ... }

dvb_usb_read_remote_control() { ... err = d->props.rc.core.rc_query(d); if (err) err(...) // Did not return even if query failed schedule_delayed_work(&d->rc_query_work, msecs_to_jiffies(rc_interval)); }

When the infinite log printing occurs, the query callback 'd->props.rc.core.rc_query' is cxusb_rc_query(). And the log is due to the failure of finding a valid 'generic_bulk_ctrl_endpoint' in usb_bulk_msg(), see following code snippet:

cxusb_rc_query() { cxusb_ctrl_msg() { dvb_usb_generic_rw() { ret = usb_bulk_msg(d->udev, usb_sndbulkpipe(d->udev, d->props.generic_bulk_ctrl_endpoint),...); if (ret) err("bulk message failed: %d (%d/%d)",ret,wlen,actlen); ... } ... }

By analyzing the corresponding USB descriptor, it shows that the bNumEndpoints is 0 in its interface descriptor, but the 'generic_bulk_ctrl_endpoint' is 1, that means user don't configure a valid endpoint for 'generic_bulk_ctrl_endpoint', therefore this 'invalid' USB device should be rejected before it calls into dvb_usb_read_remote_control().

To fix it, iiuc, we can add endpoint check in dvb_usb_adapter_init().

Signed-off-by: Zheng Yejian zhengyejian1@huawei.com --- drivers/media/usb/dvb-usb/dvb-usb-init.c | 8 ++++++++ 1 file changed, 8 insertions(+)

diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c index 58eea8ab5477..d8098c110450 100644 --- a/drivers/media/usb/dvb-usb/dvb-usb-init.c +++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c @@ -104,6 +104,14 @@ static int dvb_usb_adapter_init(struct dvb_usb_device *d, short *adapter_nrs) * sometimes a timeout occurs, this helps */ if (d->props.generic_bulk_ctrl_endpoint != 0) { + ret = usb_pipe_type_check(d->udev, usb_sndbulkpipe(d->udev, + d->props.generic_bulk_ctrl_endpoint)); + if (ret) + goto frontend_init_err; + ret = usb_pipe_type_check(d->udev, usb_rcvbulkpipe(d->udev, + d->props.generic_bulk_ctrl_endpoint)); + if (ret) + goto frontend_init_err; usb_clear_halt(d->udev, usb_sndbulkpipe(d->udev, d->props.generic_bulk_ctrl_endpoint)); usb_clear_halt(d->udev, usb_rcvbulkpipe(d->udev, d->props.generic_bulk_ctrl_endpoint)); }