From: Julia Lawall <julia@xxxxxxx> Memset on a local variable may be removed when it is called just before the variable goes out of scope. Using memzero_explicit defeats this optimization. A simplified version of the semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ identifier x; type T; @@ { ... when any T x[...]; ... when any when exists - memset + memzero_explicit (x, -0, ...) ... when != x when strict } // </smpl> This change was suggested by Daniel Borkmann <dborkman@xxxxxxxxxx> Signed-off-by: Julia Lawall <julia@xxxxxxx> --- Daniel Borkmann suggested that these patches could go through Herbert Xu's cryptodev tree. arch/x86/crypto/sha256_ssse3_glue.c | 2 +- arch/x86/crypto/sha512_ssse3_glue.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/crypto/sha512_ssse3_glue.c b/arch/x86/crypto/sha512_ssse3_glue.c index 26a5898..0b6af26 100644 --- a/arch/x86/crypto/sha512_ssse3_glue.c +++ b/arch/x86/crypto/sha512_ssse3_glue.c @@ -219,7 +219,7 @@ static int sha384_ssse3_final(struct shash_desc *desc, u8 *hash) sha512_ssse3_final(desc, D); memcpy(hash, D, SHA384_DIGEST_SIZE); - memset(D, 0, SHA512_DIGEST_SIZE); + memzero_explicit(D, SHA512_DIGEST_SIZE); return 0; } diff --git a/arch/x86/crypto/sha256_ssse3_glue.c b/arch/x86/crypto/sha256_ssse3_glue.c index 4dc100d..8fad72f 100644 --- a/arch/x86/crypto/sha256_ssse3_glue.c +++ b/arch/x86/crypto/sha256_ssse3_glue.c @@ -211,7 +211,7 @@ static int sha224_ssse3_final(struct shash_desc *desc, u8 *hash) sha256_ssse3_final(desc, D); memcpy(hash, D, SHA224_DIGEST_SIZE); - memset(D, 0, SHA256_DIGEST_SIZE); + memzero_explicit(D, SHA256_DIGEST_SIZE); return 0; } -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
