Commit e9c1b1ab authored Mar 15, 2017 by Eric Dumazet Committed by Greg Kroah-Hartman Mar 30, 2017

net: properly release sk_frag.page



[ Upstream commit 22a0e18eac7a9e986fec76c60fa4a2926d1291e2 ]

I mistakenly added the code to release sk->sk_frag in
sk_common_release() instead of sk_destruct()

TCP sockets using sk->sk_allocation == GFP_ATOMIC do no call
sk_common_release() at close time, thus leaking one (order-3) page.

iSCSI is using such sockets.

Fixes: 5640f768 ("net: use a per task frag allocator")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 4d5bc781

net/core/sock.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -1437,6 +1437,11 @@ static void __sk_destruct(struct rcu_head *head)
		pr_debug("%s: optmem leakage (%d bytes) detected\n",
		__func__, atomic_read(&sk->sk_omem_alloc));

		if (sk->sk_frag.page) {
		put_page(sk->sk_frag.page);
		sk->sk_frag.page = NULL;
		}

		if (sk->sk_peer_cred)
		put_cred(sk->sk_peer_cred);
		put_pid(sk->sk_peer_pid);
		@@ -2738,11 +2743,6 @@ void sk_common_release(struct sock *sk)

		sk_refcnt_debug_release(sk);

		if (sk->sk_frag.page) {
		put_page(sk->sk_frag.page);
		sk->sk_frag.page = NULL;
		}

		sock_put(sk);
		}
		EXPORT_SYMBOL(sk_common_release);