4.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit 1f3b359f1004bd34b7b0bad70b93e3c7af92a37b ]
While the cited commit fixed a possible deadlock, it added a leak
of the request socket, since reqsk_put() must be called if the BPF
filter decided the ACK packet must be dropped.
Fixes: d624d276d1dd ("tcp: fix possible deadlock in TCP stack vs BPF filter")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Acked-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/tcp_ipv4.c | 6 +++---
net/ipv6/tcp_ipv6.c | 6 +++---
2 files changed, 6 insertions(+), 6 deletions(-)
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1722,9 +1722,9 @@ process:
*/
sock_hold(sk);
refcounted = true;
- if (tcp_filter(sk, skb))
- goto discard_and_relse;
- nsk = tcp_check_req(sk, skb, req, false);
+ nsk = NULL;
+ if (!tcp_filter(sk, skb))
+ nsk = tcp_check_req(sk, skb, req, false);
if (!nsk) {
reqsk_put(req);
goto discard_and_relse;
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1456,9 +1456,9 @@ process:
}
sock_hold(sk);
refcounted = true;
- if (tcp_filter(sk, skb))
- goto discard_and_relse;
- nsk = tcp_check_req(sk, skb, req, false);
+ nsk = NULL;
+ if (!tcp_filter(sk, skb))
+ nsk = tcp_check_req(sk, skb, req, false);
if (!nsk) {
reqsk_put(req);
goto discard_and_relse;