[PATCH 3.18 020/120] crypto: skcipher - Fix -Wstringop-truncation warnings

Greg Kroah-Hartman
2018-10-11T15:38:49Z

From: Stafford Horne <shorne@gmail.com>

[ Upstream commit cefd769fd0192c84d638f66da202459ed8ad63ba ]

As of GCC 9.0.0 the build is reporting warnings like:

crypto/ablkcipher.c: In function ‘crypto_ablkcipher_report’:
crypto/ablkcipher.c:374:2: warning: ‘strncpy’ specified bound 64 equals destination size [-Wstringop-truncation]
strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sizeof(rblkcipher.geniv));
~~~~~~~~~~~~~~~~~~~~~~~~~

This means the strnycpy might create a non null terminated string. Fix this by
explicitly performing '\0' termination.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: Nick Desaulniers <nick.desaulniers@gmail.com>
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
crypto/ablkcipher.c | 2 ++
crypto/blkcipher.c | 1 +
2 files changed, 3 insertions(+)

--- a/crypto/ablkcipher.c
+++ b/crypto/ablkcipher.c
@@ -382,6 +382,7 @@ static int crypto_ablkcipher_report(stru
strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
sizeof(rblkcipher.geniv));
+ rblkcipher.geniv[sizeof(rblkcipher.geniv) - 1] = '\0';

rblkcipher.blocksize = alg->cra_blocksize;
rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
@@ -463,6 +464,7 @@ static int crypto_givcipher_report(struc
strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
sizeof(rblkcipher.geniv));
+ rblkcipher.geniv[sizeof(rblkcipher.geniv) - 1] = '\0';

rblkcipher.blocksize = alg->cra_blocksize;
rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
--- a/crypto/blkcipher.c
+++ b/crypto/blkcipher.c
@@ -514,6 +514,7 @@ static int crypto_blkcipher_report(struc
strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
sizeof(rblkcipher.geniv));
+ rblkcipher.geniv[sizeof(rblkcipher.geniv) - 1] = '\0';

rblkcipher.blocksize = alg->cra_blocksize;
rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;