From: Toby Gray Date: Thu, 2 Sep 2010 09:46:20 +0000 (+0100) Subject: USB: cdc-acm: Fixing crash when ACM probing interfaces with no endpoint descriptors. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=577045c0a76e34294f902a7d5d60e90b04d094d0;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git USB: cdc-acm: Fixing crash when ACM probing interfaces with no endpoint descriptors. Certain USB devices, such as the Nokia X6 mobile phone, don't expose any endpoint descriptors on some of their interfaces. If the ACM driver is forced to probe all interfaces on a device the a NULL pointer dereference will occur when the ACM driver attempts to use the endpoint of the alternative settings. One way to get the ACM driver to probe all the interfaces is by using the /sys/bus/usb/drivers/cdc_acm/new_id interface. This patch checks that the endpoint pointer for the current alternate settings is non-NULL before using it. Signed-off-by: Toby Gray Cc: Oliver Neukum Cc: stable Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 597defc1d7bf..bc62fae0680f 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -965,7 +965,8 @@ static int acm_probe(struct usb_interface *intf, } if (!buflen) { - if (intf->cur_altsetting->endpoint->extralen && + if (intf->cur_altsetting->endpoint && + intf->cur_altsetting->endpoint->extralen && intf->cur_altsetting->endpoint->extra) { dev_dbg(&intf->dev, "Seeking extra descriptors on endpoint\n");