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 9365fa510c6f82e3aa550a09d0c5c6b44dbc78ff ]
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 ignat@cloudflare.com Reviewed-by: Kuniyuki Iwashima kuniyu@amazon.com Reviewed-by: Eric Dumazet edumazet@google.com Link: https://patch.msgid.link/20241014153808.51894-7-ignat@cloudflare.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 be2b786cee2bd..486ab202303ff 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -369,32 +369,30 @@ 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; }