From: Seungjin Bae Date: Sun, 28 Sep 2025 18:56:11 +0000 (-0400) Subject: USB: Fix descriptor count when handling invalid MBIM extended descriptor X-Git-Tag: v6.19-rc1~63^2~101 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5570ad1423ee60f6e972dadb63fb2e5f90a54cbe;p=thirdparty%2Fkernel%2Flinux.git USB: Fix descriptor count when handling invalid MBIM extended descriptor In cdc_parse_cdc_header(), the check for the USB_CDC_MBIM_EXTENDED_TYPE descriptor was using 'break' upon detecting an invalid length. This was incorrect because 'break' only exits the switch statement, causing the code to fall through to cnt++, thus incorrectly incrementing the count of parsed descriptors for a descriptor that was actually invalid and being discarded. This patch changes 'break' to 'goto next_desc;' to ensure that the logic skips the counter increment and correctly proceeds to the next descriptor in the buffer. This maintains an accurate count of only the successfully parsed descriptors. Fixes: e4c6fb7794982 ("usbnet: move the CDC parser into USB core") Signed-off-by: Seungjin Bae Link: https://lore.kernel.org/r/20250928185611.764589-1-eeodqql09@gmail.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index d2b2787be4092..6138468c67c47 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -2431,7 +2431,7 @@ int cdc_parse_cdc_header(struct usb_cdc_parsed_header *hdr, break; case USB_CDC_MBIM_EXTENDED_TYPE: if (elength < sizeof(struct usb_cdc_mbim_extended_desc)) - break; + goto next_desc; hdr->usb_cdc_mbim_extended_desc = (struct usb_cdc_mbim_extended_desc *)buffer; break;