linux-kernel - [PATCH] USB: gadget: g_fs: possible invalid pointer reference bug fixed

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-id: <f8fbee30a711b740b5875514715c3c58b4eb196c.1276170819.git.m.nazarewicz@samsung.com>
Date:	Mon, 14 Jun 2010 10:43:34 +0200
From:	Michal Nazarewicz <m.nazarewicz@...sung.com>
To:	linux-usb@...r.kernel.org
Cc:	David Brownell <dbrownell@...rs.sourceforge.net>,
	Kyungmin Park <kyungmin.park@...sung.com>,
	Marek Szyprowski <m.szyprowski@...sung.com>,
	linux-kernel@...r.kernel.org
Subject: [PATCH] USB: gadget: g_fs: possible invalid pointer reference bug fixed

During __gfs_do_config() some invalid pointers may be left
in usb_configuration::interfaces array from previous calls
to the __gfs_do_config() for the same configuration.  This
will always happen if an user space function which has
a fewer then the last user space function registers itself.
Composite's set_config() function that a pointer after the
last interface in usb_configuration::interface is NULL
unless the array is full.

This patch makes the __gfs_do_config() make sure that if the
usb_configuration::interface is not full then a pointer
after the last interface is NULL.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@...sung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@...sung.com>
---
 drivers/usb/gadget/g_ffs.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/usb/gadget/g_ffs.c b/drivers/usb/gadget/g_ffs.c
index 2f26470..da3a9e4 100644
--- a/drivers/usb/gadget/g_ffs.c
+++ b/drivers/usb/gadget/g_ffs.c
@@ -392,6 +392,17 @@ static int __gfs_do_config(struct usb_configuration *c,
 	if (unlikely(ret < 0))
 		return ret;
 
+	/* After previous do_configs there may be some invalid
+	 * pointers in c->interface array.  This happens every time
+	 * a user space function with fewer interfaces than a user
+	 * space function that was run before the new one is run.  The
+	 * compasit's set_config() assumes that if there is no more
+	 * then MAX_CONFIG_INTERFACES interfaces in a configuration
+	 * then there is a NULL pointer after the last interface in
+	 * c->interface array.  We need to make sure this is true. */
+	if (c->next_interface_id < ARRAY_SIZE(c->interface))
+		c->interface[c->next_interface_id] = NULL;
+
 	return 0;
 }
 
-- 
1.7.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/