3.16.62-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Alan Stern <st...@rowland.harvard.edu>

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 <st...@rowland.harvard.edu>
Reported-by: syzbot+19c3aaef85a89d451...@syzkaller.appspotmail.com
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/usb/core/usb.c | 2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -79,6 +79,8 @@ struct usb_host_interface *usb_find_alt_
        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) {

Reply via email to