From: Julia Lawall <Julia.Lawall@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.Lawall@xxxxxxx> --- Daniel Borkmann suggested that these patches could go through Herbert Xu's cryptodev tree. v2: fixed email address arch/x86/purgatory/sha256.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/purgatory/sha256.c b/arch/x86/purgatory/sha256.c index 548ca67..8271ca5 100644 --- a/arch/x86/purgatory/sha256.c +++ b/arch/x86/purgatory/sha256.c @@ -205,7 +205,7 @@ static void sha256_transform(u32 *state, const u8 *input) /* clear any sensitive info... */ a = b = c = d = e = f = g = h = t1 = t2 = 0; - memset(W, 0, 64 * sizeof(u32)); + memzero_explicit(W, 64 * sizeof(u32)); } int sha256_init(struct sha256_state *sctx) -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
