net: sctp: fix array overrun read on sctp_timer_tbl

Table sctp_timer_tbl is missing a TIMEOUT_RECONF string so
add this in. Also compare timeout with the size of the array
sctp_timer_tbl rather than SCTP_EVENT_TIMEOUT_MAX.  Also add
a build time check that SCTP_EVENT_TIMEOUT_MAX is correct
so we don't ever get this kind of mismatch between the table
and SCTP_EVENT_TIMEOUT_MAX in the future.

Kudos to Marcelo Ricardo Leitner for spotting the missing string
and suggesting the build time sanity check.

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

Fixes: 7b9438de0c ("sctp: add stream reconf timer")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Colin Ian King 2017-01-24 09:25:54 +00:00 committed by David S. Miller
parent 7110fe471e
commit 1464086939

View File

@ -159,6 +159,7 @@ static const char *const sctp_timer_tbl[] = {
"TIMEOUT_T4_RTO",
"TIMEOUT_T5_SHUTDOWN_GUARD",
"TIMEOUT_HEARTBEAT",
"TIMEOUT_RECONF",
"TIMEOUT_SACK",
"TIMEOUT_AUTOCLOSE",
};
@ -166,7 +167,9 @@ 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)
BUILD_BUG_ON(SCTP_EVENT_TIMEOUT_MAX + 1 != ARRAY_SIZE(sctp_timer_tbl));
if (id.timeout < ARRAY_SIZE(sctp_timer_tbl))
return sctp_timer_tbl[id.timeout];
return "unknown_timer";
}