[PATCH] net: tls: fix a memory leak bug

From: Wenwen Wang <wang6495@umn.edu>
To: Wenwen Wang <wang6495@umn.edu>
Cc: Boris Pismenny <borisp@mellanox.com>,
	Aviad Yehezkel <aviadye@mellanox.com>,
	Dave Watson <davejwatson@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	Daniel Borkmann <daniel@iogearbox.net>,
	"David S. Miller" <davem@davemloft.net>,
	netdev@vger.kernel.org (open list:NETWORKING [TLS]),
	linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] net: tls: fix a memory leak bug
Date: Wed, 24 Apr 2019 15:18:07 -0500	[thread overview]
Message-ID: <1556137087-25814-1-git-send-email-wang6495@umn.edu> (raw)

In decrypt_internal(), a memory block 'mem' is allocated through kmalloc()
to hold aead_req, sgin[], sgout[], aad, and iv. This memory block should be
freed after it is used, before this function is returned. However, if the
return value of the function invocation of tls_do_decryption() is
-EINPROGRESS, this memory block is actually not freed, which is a memory
leak bug.

To fix this issue, free the allocated block before the error code
-EINPROGRESS is returned.

Signed-off-by: Wenwen Wang <wang6495@umn.edu>
---
 net/tls/tls_sw.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c
index b50ced8..22445bb 100644
--- a/net/tls/tls_sw.c
+++ b/net/tls/tls_sw.c
@@ -1445,8 +1445,10 @@ static int decrypt_internal(struct sock *sk, struct sk_buff *skb,
 	/* Prepare and submit AEAD request */
 	err = tls_do_decryption(sk, skb, sgin, sgout, iv,
 				data_len, aead_req, async);
-	if (err == -EINPROGRESS)
+	if (err == -EINPROGRESS) {
+		kfree(mem);
 		return err;
+	}
 
 	/* Release the pages in case iov was mapped to pages */
 	for (; pages > 0; pages--)
-- 
2.7.4

