net/packet: fix memory leak in packet_set_ring()

syzbot found we can leak memory in packet_set_ring(), if user application
provides buggy parameters.

Fixes: 7f953ab2ba46 ("af_packet: TX_RING support for TPACKET_V3")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a29d66d..0b4cf94 100644 (file)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4314,7 +4314,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
                                    req3->tp_sizeof_priv ||
                                    req3->tp_feature_req_word) {
                                        err = -EINVAL;
-                                       goto out;
+                                       goto out_free_pg_vec;
                                }
                        }
                        break;
@@ -4378,6 +4378,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
                        prb_shutdown_retire_blk_timer(po, rb_queue);
        }
 
+out_free_pg_vec:
        if (pg_vec)
                free_pg_vec(pg_vec, order, req->tp_block_nr);
 out: