[PATCH 4.4 057/101] net: sctp: fix array overrun read on sctp_timer_tbl

Greg Kroah-Hartman
2017-07-03T13:40:14Z

From: Colin Ian King <colin.king@canonical.com>

[ 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>
---
net/sctp/debug.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- 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";
}