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From 75e5b4849b81e19e9efe1654b30d7f3151c33c2c Mon Sep 17 00:00:00 2001
From: Szymon Heidrich <szymon.heidrich@gmail.com>
Date: Mon, 24 Jan 2022 12:14:00 +0100
Subject: [PATCH] USB: gadget: validate interface OS descriptor requests
Git-commit: 75e5b4849b81e19e9efe1654b30d7f3151c33c2c
Patch-mainline: v5.17-rc4
References: CVE-2022-25258 bsc#1196095 git-fixes

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>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/usb/gadget/composite.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 16f9e3423c9f..9315313108c9 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1988,6 +1988,9 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 				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);
-- 
2.31.1