From: Tudor-Dan Ambarus <tudor.ambarus@microchip.com>
Subject: crypto: dh - fix memleak in setkey
Git-commit: ee34e2644a78e2561742bea8c4bdcf83cabf90a7
Patch-mainline: v4.13-rc1
References: bsc#1086994

setkey can be called multiple times during the existence
of the transformation object. In case of multiple setkey calls,
the old key was not freed and we leaked memory.
Free the old MPI key if any.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Jeff Mahoney <jeffm@suse.com>
---
 crypto/dh.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/crypto/dh.c b/crypto/dh.c
index 7cec04985b9d..e151f12775ca 100644
--- a/crypto/dh.c
+++ b/crypto/dh.c
@@ -85,6 +85,9 @@ static int dh_set_secret(struct crypto_kpp *tfm, const void *buf,
 	struct dh_ctx *ctx = dh_get_ctx(tfm);
 	struct dh params;
 
+	/* Free the old MPI key if any */
+	dh_free_ctx(ctx);
+
 	if (crypto_dh_decode_key(buf, len, &params) < 0)
 		return -EINVAL;