Thread (31 messages) 31 messages, 7 authors, 2024-10-16

[PATCH net-next v3 6/9] net: inet: do not leave a dangling sk pointer in inet_create()

flat view
STALE733d LANDED

From: Ignat Korchagin <hidden>
Date: 2024-10-14 15:38:35
Also in: linux-bluetooth, linux-can, lkml
Subsystem: networking [general], the rest · Maintainers: "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

Revision v3 of 2 in this series; landed in mainline as 9365fa510c6f on 2024-10-16.

Revisions (2)
  1. v2 [diff vs current]
  2. v3 current
sock_init_data() attaches the allocated sk object to the provided sock
object. If inet_create() fails later, the sk object is freed, but the
sock object retains the dangling pointer, which may create use-after-free
later.

Clear the sk pointer in the sock object on error.

Signed-off-by: Ignat Korchagin <redacted>
---
 net/ipv4/af_inet.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index b24d74616637..8095e82de808 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -376,32 +376,30 @@ static int inet_create(struct net *net, struct socket *sock, int protocol,
 		inet->inet_sport = htons(inet->inet_num);
 		/* Add to protocol hash chains. */
 		err = sk->sk_prot->hash(sk);
-		if (err) {
-			sk_common_release(sk);
-			goto out;
-		}
+		if (err)
+			goto out_sk_release;
 	}
 
 	if (sk->sk_prot->init) {
 		err = sk->sk_prot->init(sk);
-		if (err) {
-			sk_common_release(sk);
-			goto out;
-		}
+		if (err)
+			goto out_sk_release;
 	}
 
 	if (!kern) {
 		err = BPF_CGROUP_RUN_PROG_INET_SOCK(sk);
-		if (err) {
-			sk_common_release(sk);
-			goto out;
-		}
+		if (err)
+			goto out_sk_release;
 	}
 out:
 	return err;
 out_rcu_unlock:
 	rcu_read_unlock();
 	goto out;
+out_sk_release:
+	sk_common_release(sk);
+	sock->sk = NULL;
+	goto out;
 }
 
 
-- 
2.39.5
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help