[PATCH AUTOSEL 4.19 07/21] net: af_can: do not leave a dangling sk pointer in can_create()

[Sasha Levin <sashal@kernel.org>]

From: Ignat Korchagin <ignat@cloudflare.com>

[ Upstream commit 811a7ca7320c062e15d0f5b171fe6ad8592d1434 ]

On error can_create() frees the allocated sk object, but sock_init_data()
has already attached it to the provided sock object. This will leave a
dangling sk pointer in the sock object and may cause use-after-free later.

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://patch.msgid.link/20241014153808.51894-5-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/can/af_can.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/can/af_can.c b/net/can/af_can.c
index b3edb80921248..2e6fedffddd92 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -187,6 +187,7 @@ static int can_create(struct net *net, struct socket *sock, int protocol,
 		/* release sk on errors */
 		sock_orphan(sk);
 		sock_put(sk);
+		sock->sk = NULL;
 	}
 
  errout:
-- 
2.43.0