sock_init_data() attaches the allocated sk object to the provided sock
object. If ieee802154_create() fails later, the allocated sk object is
freed, but the dangling pointer remains in the provided sock object, which
may allow use-after-free.

Clear the sk pointer in the sock object on error.

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
---
 net/ieee802154/socket.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/net/ieee802154/socket.c b/net/ieee802154/socket.c
index 990a83455dcf..18d267921bb5 100644
--- a/net/ieee802154/socket.c
+++ b/net/ieee802154/socket.c
@@ -1043,19 +1043,21 @@ static int ieee802154_create(struct net *net, struct socket *sock,
 
 	if (sk->sk_prot->hash) {
 		rc = sk->sk_prot->hash(sk);
-		if (rc) {
-			sk_common_release(sk);
-			goto out;
-		}
+		if (rc)
+			goto out_sk_release;
 	}
 
 	if (sk->sk_prot->init) {
 		rc = sk->sk_prot->init(sk);
 		if (rc)
-			sk_common_release(sk);
+			goto out_sk_release;
 	}
 out:
 	return rc;
+out_sk_release:
+	sk_common_release(sk);
+	sock->sk = NULL;
+	goto out;
 }
 
 static const struct net_proto_family ieee802154_family_ops = {
-- 
2.39.5

Hi Ignat,

ignat@cloudflare.com wrote on Mon,  7 Oct 2024 22:35:00 +0100:

> sock_init_data() attaches the allocated sk object to the provided sock
> object. If ieee802154_create() fails later, the allocated sk object is
> freed, but the dangling pointer remains in the provided sock object, which
> may allow use-after-free.
> 
> Clear the sk pointer in the sock object on error.
> 
> Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks,
Miquèl