[PATCH net] net/packet: fix memory leak in packet_set_ring()

[PATCH net] net/packet: fix memory leak in packet_set_ring()

[Eric Dumazet]

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>
---
 net/packet/af_packet.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index a29d66da7394bb48c4012b29ff2ad3d256cf7bff..0b4cf94f0233f86c196e767dc0179c38330ecca7 100644
--- 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:
-- 
2.22.0.410.gd8fdbe21b5-goog

Re: [PATCH net] net/packet: fix memory leak in packet_set_ring()

[David Miller]

From: Eric Dumazet <edumazet@google.com>
Date: Mon, 24 Jun 2019 02:38:20 -0700

> 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>

Applied and queued up for -stable, thanks Eric.