From 704620afc70cf47abb9d6a1a57f3825d2bca49cf Mon Sep 17 00:00:00 2001 From: Mathias Payer Date: Wed, 5 Dec 2018 21:19:59 +0100 Subject: USB: check usb_get_extra_descriptor for proper size When reading an extra descriptor, we need to properly check the minimum and maximum size allowed, to prevent from invalid data being sent by a device. Reported-by: Hui Peng Reported-by: Mathias Payer Co-developed-by: Linus Torvalds Signed-off-by: Hui Peng Signed-off-by: Mathias Payer Signed-off-by: Linus Torvalds Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/usb.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/usb/core/usb.c') diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 79d8bd7a612e..4ebfbd737905 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -832,14 +832,14 @@ EXPORT_SYMBOL_GPL(usb_get_current_frame_number); */ int __usb_get_extra_descriptor(char *buffer, unsigned size, - unsigned char type, void **ptr) + unsigned char type, void **ptr, size_t minsize) { struct usb_descriptor_header *header; while (size >= sizeof(struct usb_descriptor_header)) { header = (struct usb_descriptor_header *)buffer; - if (header->bLength < 2) { + if (header->bLength < 2 || header->bLength > size) { printk(KERN_ERR "%s: bogus descriptor, type %d length %d\n", usbcore_name, @@ -848,7 +848,7 @@ int __usb_get_extra_descriptor(char *buffer, unsigned size, return -1; } - if (header->bDescriptorType == type) { + if (header->bDescriptorType == type && header->bLength >= minsize) { *ptr = header; return 0; } -- cgit