[PATCH 4.9 25/30] USB: core: only clean up what we allocated

From: Greg Kroah-Hartman
Date: Tue Mar 26 2019 - 02:32:07 EST


4.9-stable review patch. If anyone has any objections, please let me know.

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

From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>

commit 32fd87b3bbf5f7a045546401dfe2894dbbf4d8c3 upstream.

When cleaning up the configurations, make sure we only free the number
of configurations and interfaces that we could have allocated.

Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/core/config.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -763,18 +763,21 @@ void usb_destroy_configuration(struct us
return;

if (dev->rawdescriptors) {
- for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
+ for (i = 0; i < dev->descriptor.bNumConfigurations &&
+ i < USB_MAXCONFIG; i++)
kfree(dev->rawdescriptors[i]);

kfree(dev->rawdescriptors);
dev->rawdescriptors = NULL;
}

- for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
+ for (c = 0; c < dev->descriptor.bNumConfigurations &&
+ c < USB_MAXCONFIG; c++) {
struct usb_host_config *cf = &dev->config[c];

kfree(cf->string);
- for (i = 0; i < cf->desc.bNumInterfaces; i++) {
+ for (i = 0; i < cf->desc.bNumInterfaces &&
+ i < USB_MAXINTERFACES; i++) {
if (cf->intf_cache[i])
kref_put(&cf->intf_cache[i]->ref,
usb_release_interface_cache);