[PATCH AUTOSEL 5.10 15/33] net: inet6: do not leave a dangling sk pointer in inet6_create()

Sasha Levin
2024-11-24T13:54:38Z

From: Ignat Korchagin <ignat@cloudflare.com>

[ Upstream commit 9df99c395d0f55fb444ef39f4d6f194ca437d884 ]

sock_init_data() attaches the allocated sk pointer to the provided sock
object. If inet6_create() fails later, the sk object is released, but the
sock object retains the dangling sk pointer, which may cause use-after-free
later.

Clear the sock sk pointer on error.

Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-8-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv6/af_inet6.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 32da2b66fa2fb..5fd203ddc0757 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -257,31 +257,29 @@ static int inet6_create(struct net *net, struct socket *sock, int protocol,
*/
inet->inet_sport = htons(inet->inet_num);
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;
}

static int __inet6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len,
--
2.43.0