From: Norbert Slusarek <nslusarek@xxxxxxx>
[ Upstream commit aaf473d0100f64abc88560e2bea905805bcf2a8e ]
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@xxxxxxx
Signed-off-by: Norbert Slusarek <nslusarek@xxxxxxx>
Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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;
--
2.30.2
