From: Szymon Heidrich <szymon.heidrich@gmail.com>
Date: Mon, 24 Jan 2022 11:14:00 +0000 (+0100)
Subject: USB: gadget: validate interface OS descriptor requests
X-Git-Tag: v4.19.230~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e5eb8d19aee115d8fb354d1eff1b8df700467164;p=thirdparty%2Fkernel%2Fstable.git

USB: gadget: validate interface OS descriptor requests

commit 75e5b4849b81e19e9efe1654b30d7f3151c33c2c upstream.

Stall the control endpoint in case provided index exceeds array size of
MAX_CONFIG_INTERFACES or when the retrieved function pointer is null.

Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 748f8fede5c23..42f267ae95984 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1930,6 +1930,9 @@ unknown:
 				if (w_index != 0x5 || (w_value >> 8))
 					break;
 				interface = w_value & 0xFF;
+				if (interface >= MAX_CONFIG_INTERFACES ||
+				    !os_desc_cfg->interface[interface])
+					break;
 				buf[6] = w_index;
 				count = count_ext_prop(os_desc_cfg,
 					interface);