[PATCH 3.10 088/268] HID: hid-cypress: validate length of report

Willy Tarreau
2017-06-19T18:37:11Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1ebb71143758f45dc0fa76e2f48429e13b16d110 upstream.

Make sure we have enough of a report structure to validate before
looking at it.

Reported-by: Benoit Camredon <benoit.camredon@airbus.com>
Tested-by: Benoit Camredon <benoit.camredon@airbus.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
drivers/hid/hid-cypress.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/hid/hid-cypress.c b/drivers/hid/hid-cypress.c
index c4ef3bc..e299576 100644
--- a/drivers/hid/hid-cypress.c
+++ b/drivers/hid/hid-cypress.c
@@ -39,6 +39,9 @@ static __u8 *cp_report_fixup(struct hid_device *hdev, __u8 *rdesc,
if (!(quirks & CP_RDESC_SWAPPED_MIN_MAX))
return rdesc;

+ if (*rsize < 4)
+ return rdesc;
+
for (i = 0; i < *rsize - 4; i++)
if (rdesc[i] == 0x29 && rdesc[i + 2] == 0x19) {
__u8 tmp;
--
2.8.0.rc2.1.gbe9624a