From: Torsten Duwe <duwe@suse.de>
Subject: s390 crypto: explicitly memzero stack key material in aes_s390.c
Patch-mainline: Submitted, 2020-02-21 LKML
References: bsc#1163459

s390 crypto: explicitly memzero stack key material in aes_s390.c

aes_s390.c has several functions which allocate space for key material on
the stack and leave the used keys there. It is considered good practice
to clean these locations before the function returns.

Signed-off-by: Torsten Duwe <duwe@suse.de>

--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -392,6 +392,7 @@ static int cbc_aes_crypt(struct blkciphe
 		ret = blkcipher_walk_done(desc, walk, nbytes - n);
 	}
 	memcpy(walk->iv, param.iv, AES_BLOCK_SIZE);
+	memzero_explicit(&param, sizeof(param));
 	return ret;
 }
 
@@ -576,6 +577,8 @@ static int xts_aes_crypt(struct blkciphe
 			 walk->dst.virt.addr, walk->src.virt.addr, n);
 		ret = blkcipher_walk_done(desc, walk, nbytes - n);
 	}
+	memzero_explicit(&pcc_param, sizeof(pcc_param));
+	memzero_explicit(&xts_param, sizeof(xts_param));
 	return ret;
 }