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usb: core: config: reverse the size check of the SSP isoc endpoint descriptor

PATCH New Greg Kroah-Hartman 1 participant 1 message Apr 6 USB

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Greg Kroah-Hartman

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PATCH 1/1 usb: core: config: reverse the size check of the SSP isoc endpoint descriptor

Reverse the check of the size of the usb_ssp_isoc_ep_comp_descriptor structure to be done before accessing the structure itself. Functionally, this doesn't really do anything as the buffer is all internal to the kernel, and reading off the end is just fine, but static checking tools get picky when noticing that a potential read could be made "outside" of an allocated buffer.

Not a bugfix, but a cleanup to keep tools from tripping over this constantly and annoying me with their pointless reports.

Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/usb/core/config.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
drivers/usb/core/config.c +2 -2
index 6a1fd967e0a6..417140b012bb 100644
@@ -54,8 +54,8 @@ static void usb_parse_ssp_isoc_endpoint_companion(struct device *ddev,
 	 * follows the SuperSpeed Endpoint Companion descriptor
 	 */
 	desc = (struct usb_ssp_isoc_ep_comp_descriptor *) buffer;
-	if (desc->bDescriptorType != USB_DT_SSP_ISOC_ENDPOINT_COMP ||
-	    size < USB_DT_SSP_ISOC_EP_COMP_SIZE) {
+	if (size < USB_DT_SSP_ISOC_EP_COMP_SIZE ||
+	    desc->bDescriptorType != USB_DT_SSP_ISOC_ENDPOINT_COMP) {
 		dev_notice(ddev, "Invalid SuperSpeedPlus isoc endpoint companion"
 			 "for config %d interface %d altsetting %d ep %d.\n",
 			 cfgno, inum, asnum, ep->desc.bEndpointAddress);
Signature · 1 line
2.53.0