[net 1/2] can: j1939: j1939_sk_setsockopt(): prevent allocation of j1939 filter for optlen == 0
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2021-06-24 06:42:11
Also in:
linux-can
Subsystem:
can network layer, can-j1939 network layer, the rest · Maintainers:
Oliver Hartkopp, Marc Kleine-Budde, Robin van der Gracht, Oleksij Rempel, Linus Torvalds
From: Norbert Slusarek <redacted>
If optval != NULL and optlen == 0 are specified for SO_J1939_FILTER in
j1939_sk_setsockopt(), memdup_sockptr() will return ZERO_PTR for 0
size allocation. The new filter will be mistakenly assigned ZERO_PTR.
This patch checks for optlen != 0 and filter will be assigned NULL in
case of optlen == 0.
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/20210620123842.117975-1-nslusarek@gmx.net (local)
Signed-off-by: Norbert Slusarek <redacted>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
net/can/j1939/socket.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c
index fce8bc8afeb7..e1a399821238 100644
--- a/net/can/j1939/socket.c
+++ b/net/can/j1939/socket.c@@ -676,7 +676,7 @@ static int j1939_sk_setsockopt(struct socket *sock, int level, int optname, switch (optname) { case SO_J1939_FILTER: - if (!sockptr_is_null(optval)) { + if (!sockptr_is_null(optval) && optlen != 0) { struct j1939_filter *f; int c;
base-commit: c2f5c57d99debf471a1b263cdf227e55f1364e95 -- 2.30.2