From 7b6e85da8d94948201abb8d576d485892a6a878f Mon Sep 17 00:00:00 2001 From: Mathias Payer Date: Wed, 5 Dec 2018 21:19:59 +0100 Subject: [PATCH] USB: check usb_get_extra_descriptor for proper size commit 704620afc70cf47abb9d6a1a57f3825d2bca49cf upstream. 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. CVE: CVE-2018-20169 Upstream-Status: Backport 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 Signed-off-by: Andreas Wellving --- drivers/usb/core/hub.c | 2 +- drivers/usb/core/usb.c | 6 +++--- drivers/usb/host/hwa-hc.c | 2 +- include/linux/usb.h | 4 ++-- 4 files changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 638dc6f66d70..a073cb5be013 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2231,7 +2231,7 @@ static int usb_enumerate_device_otg(struct usb_device *udev) /* descriptor may appear anywhere in config */ err = __usb_get_extra_descriptor(udev->rawdescriptors[0], le16_to_cpu(udev->config[0].desc.wTotalLength), - USB_DT_OTG, (void **) &desc); + USB_DT_OTG, (void **) &desc, sizeof(*desc)); if (err || !(desc->bmAttributes & USB_OTG_HNP)) return 0; diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index f8b50eaf6d1e..7a4e3da549fe 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -833,14 +833,14 @@ 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, @@ -849,7 +849,7 @@ 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; } diff --git a/drivers/usb/host/hwa-hc.c b/drivers/usb/host/hwa-hc.c index da3b18038d23..216069c396a0 100644 --- a/drivers/usb/host/hwa-hc.c +++ b/drivers/usb/host/hwa-hc.c @@ -654,7 +654,7 @@ static int hwahc_security_create(struct hwahc *hwahc) top = itr + itr_size; result = __usb_get_extra_descriptor(usb_dev->rawdescriptors[index], le16_to_cpu(usb_dev->actconfig->desc.wTotalLength), - USB_DT_SECURITY, (void **) &secd); + USB_DT_SECURITY, (void **) &secd, sizeof(*secd)); if (result == -1) { dev_warn(dev, "BUG? WUSB host has no security descriptors\n"); return 0; diff --git a/include/linux/usb.h b/include/linux/usb.h index 4192a1755ccb..8c7ba40cf021 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -407,11 +407,11 @@ struct usb_host_bos { }; int __usb_get_extra_descriptor(char *buffer, unsigned size, - unsigned char type, void **ptr); + unsigned char type, void **ptr, size_t min); #define usb_get_extra_descriptor(ifpoint, type, ptr) \ __usb_get_extra_descriptor((ifpoint)->extra, \ (ifpoint)->extralen, \ - type, (void **)ptr) + type, (void **)ptr, sizeof(**(ptr))) /* ----------------------------------------------------------------------- */ -- 2.19.2