[PATCH] net: sctp: fix array overrun read on sctp_timer_tbl

[Colin King]

From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The comparison on the timeout can lead to an array overrun
read on sctp_timer_tbl because of an off-by-one error. Fix
this by using < instead of <= and also compare to the array
size rather than SCTP_EVENT_TIMEOUT_MAX.

Fixes CoverityScan CID#1397639 ("Out-of-bounds read")

Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
 net/sctp/debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sctp/debug.c b/net/sctp/debug.c
index 95d7b15..e371a0d 100644
--- a/net/sctp/debug.c
+++ b/net/sctp/debug.c
@@ -166,7 +166,7 @@ static const char *const sctp_timer_tbl[] = {
 /* Lookup timer debug name. */
 const char *sctp_tname(const sctp_subtype_t id)
 {
-	if (id.timeout <= SCTP_EVENT_TIMEOUT_MAX)
+	if (id.timeout < ARRAY_SIZE(sctp_timer_tbl))
 		return sctp_timer_tbl[id.timeout];
 	return "unknown_timer";
 }
-- 
2.10.2