[PATCH 4.9 17/28] net: diag: Dont double-free TCP_NEW_SYN_RECV sockets in tcp_abort

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Lorenzo Colitti <lorenzo@google.com>

[ Upstream commit acc2cf4e37174646a24cba42fa53c668b2338d4e ]

When tcp_diag_destroy closes a TCP_NEW_SYN_RECV socket, it first
frees it by calling inet_csk_reqsk_queue_drop_and_and_put in
tcp_abort, and then frees it again by calling sock_gen_put.

Since tcp_abort only has one caller, and all the other codepaths
in tcp_abort don't free the socket, just remove the free in that
function.

Cc: David Ahern <dsa@cumulusnetworks.com>
Tested: passes Android sock_diag_test.py, which exercises this codepath
Fixes: d7226c7a4dd1 ("net: diag: Fix refcnt leak in error path destroying socket")
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/tcp.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3238,8 +3238,7 @@ int tcp_abort(struct sock *sk, int err)
 			struct request_sock *req = inet_reqsk(sk);
 
 			local_bh_disable();
-			inet_csk_reqsk_queue_drop_and_put(req->rsk_listener,
-							  req);
+			inet_csk_reqsk_queue_drop(req->rsk_listener, req);
 			local_bh_enable();
 			return 0;
 		}