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authorAlan Stern <stern@rowland.harvard.edu>2017-10-18 12:49:38 -0400
committerEric Olsen <eolsen@google.com>2018-07-06 14:12:29 -0700
commitc9af97361b969828a1e2c9c4e8e2521c6cfaae93 (patch)
treea200451d4f03863e6feff785e7f3d57958cde040
parent9fdf03ab942b5bcb3a106176c9639a57813ecd8f (diff)
downloadqcom-msm8x09-v3.10-c9af97361b969828a1e2c9c4e8e2521c6cfaae93.tar.gz
USB: core: fix out-of-bounds access bug in usb_get_bos_descriptor()
Andrey used the syzkaller fuzzer to find an out-of-bounds memory access in usb_get_bos_descriptor(). The code wasn't checking that the next usb_dev_cap_header structure could fit into the remaining buffer space. This patch fixes the error and also reduces the bNumDeviceCaps field in the header to match the actual number of capabilities found, in cases where there are fewer than expected. Change-Id: I4dcdbd4d5be97a01a6c3bf9020985c7979c04f29 Git-commit: 1c0edc3633b56000e18d82fc241e3995ca18a69e Git-repo: https://github.com/torvalds/linux Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Andrey Konovalov <andreyknvl@google.com> CC: <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Srinivasa Rao Kuppala <srkupp@codeaurora.org>
-rw-r--r--drivers/usb/core/config.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index 6b3ca727f35..98a87503378 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -828,10 +828,12 @@ int usb_get_bos_descriptor(struct usb_device *dev)
for (i = 0; i < num; i++) {
buffer += length;
cap = (struct usb_dev_cap_header *)buffer;
- length = cap->bLength;
- if (total_len < length)
+ if (total_len < sizeof(*cap) || total_len < cap->bLength) {
+ dev->bos->desc->bNumDeviceCaps = i;
break;
+ }
+ length = cap->bLength;
total_len -= length;
if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) {