Commit f588c0db authored Jun 14, 2010 by Michal Nazarewicz Committed by Greg Kroah-Hartman Jun 30, 2010

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@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

parent b23097b7

drivers/usb/gadget/g_ffs.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

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