From: Norbert Slusarek nslusarek@gmx.net
[ 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@gmx.net Signed-off-by: Norbert Slusarek nslusarek@gmx.net Acked-by: Oleksij Rempel o.rempel@pengutronix.de Signed-off-by: Marc Kleine-Budde mkl@pengutronix.de Signed-off-by: Sasha Levin sashal@kernel.org --- 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;