[34-longterm 020/209] irda: Fix parameter extraction stack overflow

[Paul Gortmaker]

From: Samuel Ortiz <samuel@xxxxxxxxxx>

  =====================================================================
  | This is a commit scheduled for the next v2.6.34 longterm release. |
  | If you see a problem with using this for longterm, please comment.|
  =====================================================================

commit efc463eb508798da4243625b08c7396462cabf9f upstream.

Reported-by: Ilja Van Sprundel <ivansprundel@xxxxxxxxxxxx>
Signed-off-by: Samuel Ortiz <samuel@xxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
 net/irda/parameters.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/net/irda/parameters.c b/net/irda/parameters.c
index fc1a205..71cd38c 100644
--- 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 */
 
-- 
1.7.4.4

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