irda: Fix parameter extraction stack overflow

commit efc463eb508798da4243625b08c7396462cabf9f upstream.

Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
Signed-off-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/irda/parameters.c b/net/irda/parameters.c
index fc1a205..71cd38c 100644 (file)
--- a/net/irda/parameters.c
+++ b/net/irda/parameters.c
@@ -298,6 +298,8 @@ static int irda_extract_string(void *self, __u8 *buf, int len, __u8 pi,
 
        p.pi = pi;     /* In case handler needs to know */
        p.pl = buf[1]; /* Extract length of value */
+       if (p.pl > 32)
+               p.pl = 32;
 
        IRDA_DEBUG(2, "%s(), pi=%#x, pl=%d\n", __func__,
                   p.pi, p.pl);
@@ -318,7 +320,7 @@ static int irda_extract_string(void *self, __u8 *buf, int len, __u8 pi,
                   (__u8) str[0], (__u8) str[1]);
 
        /* Null terminate string */
-       str[p.pl+1] = '\0';
+       str[p.pl] = '\0';
 
        p.pv.c = str; /* Handler will need to take a copy */