iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

USB: handle NULL config in usb_find_alt_setting()

Browse Source 
commit c9a4cb204e9eb7fa7dfbe3f7d3a674fa530aa193 upstream.

usb_find_alt_setting() takes a pointer to a struct usb_host_config as
an argument; it searches for an interface with specified interface and
alternate setting numbers in that config.  However, it crashes if the
usb_host_config pointer argument is NULL.

Since this is a general-purpose routine, available for use in many
places, we want to to be more robust.  This patch makes it return NULL
whenever the config argument is NULL.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: syzbot+19c3aaef85a89d451eac@syzkaller.appspotmail.com
CC: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Alan Stern 2018-09-10 14:00:53 -04:00 committed by Greg Kroah-Hartman
parent ae96945ac6
commit 06fc0ef3ef
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/usb/core/usb.c
View File

@ -95,6 +95,8 @@ struct usb_host_interface *usb_find_alt_setting(
struct usb_interface_cache *intf_cache = NULL;
int i;
if (!config)
return NULL;
for (i = 0; i < config->desc.bNumInterfaces; i++) {
if (config->intf_cache[i]->altsetting[0].desc.bInterfaceNumber
== iface_num) {