From: Stafford Horne Subject: [RFC PATCH 1/2] crypto: Fix -Wstringop-truncation warnings Date: Sat, 23 Jun 2018 11:07:52 +0900 Message-ID: <20180623020753.27266-2-shorne@gmail.com> References: <20180623020753.27266-1-shorne@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Cc: Greg KH , arnd@arndb.de, linux-crypto@vger.kernel.org, Stafford Horne , Herbert Xu , "David S. Miller" To: LKML Return-path: In-Reply-To: <20180623020753.27266-1-shorne@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org 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 ?: "", ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ sizeof(rblkcipher.geniv)); ~~~~~~~~~~~~~~~~~~~~~~~~~ This means the strnycpy might create a non null terminated string. Fix this by limiting the size of the string copy to include the null terminator. Cc: Greg Kroah-Hartman Cc: Arnd Bergmann Signed-off-by: Stafford Horne --- crypto/ablkcipher.c | 4 ++-- crypto/blkcipher.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/crypto/ablkcipher.c b/crypto/ablkcipher.c index d880a4897159..972cd7c879f6 100644 --- a/crypto/ablkcipher.c +++ b/crypto/ablkcipher.c @@ -372,7 +372,7 @@ static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type)); strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "", - sizeof(rblkcipher.geniv)); + sizeof(rblkcipher.geniv) - 1); rblkcipher.blocksize = alg->cra_blocksize; rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize; @@ -446,7 +446,7 @@ static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg) strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type)); strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "", - sizeof(rblkcipher.geniv)); + sizeof(rblkcipher.geniv) - 1); rblkcipher.blocksize = alg->cra_blocksize; rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize; diff --git a/crypto/blkcipher.c b/crypto/blkcipher.c index 01c0d4aa2563..f1644b5cf68c 100644 --- a/crypto/blkcipher.c +++ b/crypto/blkcipher.c @@ -511,7 +511,7 @@ static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type)); strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "", - sizeof(rblkcipher.geniv)); + sizeof(rblkcipher.geniv) - 1); rblkcipher.blocksize = alg->cra_blocksize; rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize; -- 2.17.0