[PATCH 4.15 06/23] tcp: release sk_frag.page in tcp_disconnect
4.15-stable review patch. If anyone has any objections, please let me know. -- From: Li RongQing[ Upstream commit 9b42d55a66d388e4dd5550107df051a9637564fc ] socket can be disconnected and gets transformed back to a listening socket, if sk_frag.page is not released, which will be cloned into a new socket by sk_clone_lock, but the reference count of this page is increased, lead to a use after free or double free issue Signed-off-by: Li RongQing Cc: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp.c |6 ++ 1 file changed, 6 insertions(+) --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2434,6 +2434,12 @@ int tcp_disconnect(struct sock *sk, int WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); + if (sk->sk_frag.page) { + put_page(sk->sk_frag.page); + sk->sk_frag.page = NULL; + sk->sk_frag.offset = 0; + } + sk->sk_error_report(sk); return err; }
[PATCH 4.15 06/23] tcp: release sk_frag.page in tcp_disconnect
4.15-stable review patch. If anyone has any objections, please let me know. -- From: Li RongQing [ Upstream commit 9b42d55a66d388e4dd5550107df051a9637564fc ] socket can be disconnected and gets transformed back to a listening socket, if sk_frag.page is not released, which will be cloned into a new socket by sk_clone_lock, but the reference count of this page is increased, lead to a use after free or double free issue Signed-off-by: Li RongQing Cc: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp.c |6 ++ 1 file changed, 6 insertions(+) --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2434,6 +2434,12 @@ int tcp_disconnect(struct sock *sk, int WARN_ON(inet->inet_num && !icsk->icsk_bind_hash); + if (sk->sk_frag.page) { + put_page(sk->sk_frag.page); + sk->sk_frag.page = NULL; + sk->sk_frag.offset = 0; + } + sk->sk_error_report(sk); return err; }