net: sctp: fix array overrun read on sctp_timer_tbl

[ Upstream commit 0e73fc9a56f22f2eec4d2b2910c649f7af67b74d ]

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@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/sctp/debug.c b/net/sctp/debug.c
index 95d7b15..e371a0d 100644 (file)
--- 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";
 }