Without the barrier_data() inside memzero_explicit(), the compiler may
optimize away the state-clearing if it can tell that the state is not
used afterwards. At least in lib/crypto/sha256.c:__sha256_final(), the
function can get inlined into sha256(), in which case the memset is
optimized away.
Signed-off-by: Arvind Sankar <nived...@alum.mit.edu>
---
arch/arm64/crypto/ghash-ce-glue.c | 2 +-
arch/arm64/crypto/poly1305-glue.c | 2 +-
arch/arm64/crypto/sha3-ce-glue.c | 2 +-
arch/x86/crypto/poly1305_glue.c | 2 +-
include/crypto/sha1_base.h | 3 ++-
include/crypto/sha256_base.h | 3 ++-
include/crypto/sha512_base.h | 3 ++-
include/crypto/sm3_base.h | 3 ++-
lib/crypto/sha256.c | 2 +-
9 files changed, 13 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/crypto/ghash-ce-glue.c
b/arch/arm64/crypto/ghash-ce-glue.c
index 8536008e3e35..2427e2f3a9a1 100644
--- a/arch/arm64/crypto/ghash-ce-glue.c
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -168,7 +168,7 @@ static int ghash_final(struct shash_desc *desc, u8 *dst)
put_unaligned_be64(ctx->digest[1], dst);
put_unaligned_be64(ctx->digest[0], dst + 8);
- *ctx = (struct ghash_desc_ctx){};
+ memzero_explicit(ctx, sizeof(*ctx));
return 0;
}
diff --git a/arch/arm64/crypto/poly1305-glue.c
b/arch/arm64/crypto/poly1305-glue.c
index f33ada70c4ed..683de671741a 100644
--- a/arch/arm64/crypto/poly1305-glue.c
+++ b/arch/arm64/crypto/poly1305-glue.c
@@ -177,7 +177,7 @@ void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8
*dst)
}
poly1305_emit(&dctx->h, dst, dctx->s);
- *dctx = (struct poly1305_desc_ctx){};
+ memzero_explicit(dctx, sizeof(*dctx));
}
EXPORT_SYMBOL(poly1305_final_arch);
diff --git a/arch/arm64/crypto/sha3-ce-glue.c b/arch/arm64/crypto/sha3-ce-glue.c
index 9a4bbfc45f40..e5a2936f0886 100644
--- a/arch/arm64/crypto/sha3-ce-glue.c
+++ b/arch/arm64/crypto/sha3-ce-glue.c
@@ -94,7 +94,7 @@ static int sha3_final(struct shash_desc *desc, u8 *out)
if (digest_size & 4)
put_unaligned_le32(sctx->st[i], (__le32 *)digest);
- *sctx = (struct sha3_state){};
+ memzero_explicit(sctx, sizeof(*sctx));
return 0;
}
diff --git a/arch/x86/crypto/poly1305_glue.c b/arch/x86/crypto/poly1305_glue.c
index e508dbd91813..64d09520d279 100644
--- a/arch/x86/crypto/poly1305_glue.c
+++ b/arch/x86/crypto/poly1305_glue.c
@@ -209,7 +209,7 @@ void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8
*dst)
}
poly1305_simd_emit(&dctx->h, dst, dctx->s);
- *dctx = (struct poly1305_desc_ctx){};
+ memzero_explicit(dctx, sizeof(*dctx));
}
EXPORT_SYMBOL(poly1305_final_arch);
diff --git a/include/crypto/sha1_base.h b/include/crypto/sha1_base.h
index 20fd1f7468af..a5d6033efef7 100644
--- a/include/crypto/sha1_base.h
+++ b/include/crypto/sha1_base.h
@@ -12,6 +12,7 @@
#include <crypto/sha.h>
#include <linux/crypto.h>
#include <linux/module.h>
+#include <linux/string.h>
#include <asm/unaligned.h>
@@ -101,7 +102,7 @@ static inline int sha1_base_finish(struct shash_desc *desc,
u8 *out)
for (i = 0; i < SHA1_DIGEST_SIZE / sizeof(__be32); i++)
put_unaligned_be32(sctx->state[i], digest++);
- *sctx = (struct sha1_state){};
+ memzero_explicit(sctx, sizeof(*sctx));
return 0;
}
diff --git a/include/crypto/sha256_base.h b/include/crypto/sha256_base.h
index 6ded110783ae..93f9fd21cc06 100644
--- a/include/crypto/sha256_base.h
+++ b/include/crypto/sha256_base.h
@@ -12,6 +12,7 @@
#include <crypto/sha.h>
#include <linux/crypto.h>
#include <linux/module.h>
+#include <linux/string.h>
#include <asm/unaligned.h>
@@ -105,7 +106,7 @@ static inline int sha256_base_finish(struct shash_desc
*desc, u8 *out)
for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be32))
put_unaligned_be32(sctx->state[i], digest++);
- *sctx = (struct sha256_state){};
+ memzero_explicit(sctx, sizeof(*sctx));
return 0;
}
diff --git a/include/crypto/sha512_base.h b/include/crypto/sha512_base.h
index fb19c77494dc..93ab73baa38e 100644
--- a/include/crypto/sha512_base.h
+++ b/include/crypto/sha512_base.h
@@ -12,6 +12,7 @@
#include <crypto/sha.h>
#include <linux/crypto.h>
#include <linux/module.h>
+#include <linux/string.h>
#include <asm/unaligned.h>
@@ -126,7 +127,7 @@ static inline int sha512_base_finish(struct shash_desc
*desc, u8 *out)
for (i = 0; digest_size > 0; i++, digest_size -= sizeof(__be64))
put_unaligned_be64(sctx->state[i], digest++);
- *sctx = (struct sha512_state){};
+ memzero_explicit(sctx, sizeof(*sctx));
return 0;
}
diff --git a/include/crypto/sm3_base.h b/include/crypto/sm3_base.h
index 1cbf9aa1fe52..2f3a32ab97bb 100644
--- a/include/crypto/sm3_base.h
+++ b/include/crypto/sm3_base.h
@@ -13,6 +13,7 @@
#include <crypto/sm3.h>
#include <linux/crypto.h>
#include <linux/module.h>
+#include <linux/string.h>
#include <asm/unaligned.h>
typedef void (sm3_block_fn)(struct sm3_state *sst, u8 const *src, int blocks);
@@ -104,7 +105,7 @@ static inline int sm3_base_finish(struct shash_desc *desc,
u8 *out)
for (i = 0; i < SM3_DIGEST_SIZE / sizeof(__be32); i++)
put_unaligned_be32(sctx->state[i], digest++);
- *sctx = (struct sm3_state){};
+ memzero_explicit(sctx, sizeof(*sctx));
return 0;
}
diff --git a/lib/crypto/sha256.c b/lib/crypto/sha256.c
index 2321f6cb322f..d43bc39ab05e 100644
--- a/lib/crypto/sha256.c
+++ b/lib/crypto/sha256.c
@@ -265,7 +265,7 @@ static void __sha256_final(struct sha256_state *sctx, u8
*out, int digest_words)
put_unaligned_be32(sctx->state[i], &dst[i]);
/* Zeroize sensitive information. */
- memset(sctx, 0, sizeof(*sctx));
+ memzero_explicit(sctx, sizeof(*sctx));
}
void sha256_final(struct sha256_state *sctx, u8 *out)
--
2.26.2
