5.4-stable review patch. If anyone has any objections, please let me know.
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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 7ee0bfea9de1d..845d77b0a7f03 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -251,31 +251,29 @@ 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,