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authorLinus Torvalds <torvalds@linux-foundation.org>2014-10-24 19:33:32 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2014-10-24 19:33:32 (GMT)
commit14d4cc08832efb724e58944ba2ac22e2ca3143dc (patch)
treefebca1365a5306d5a44b2481ec41f13f4c2defc2
parent1c45d9a920e6ef4fce38921e4fc776c2abca3197 (diff)
parent7185ad2672a7d50bc384de0e38d90b75d99f3d82 (diff)
Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull /dev/random updates from Ted Ts'o: "This adds a memzero_explicit() call which is guaranteed not to be optimized away by GCC. This is important when we are wiping cryptographically sensitive material" * tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random: crypto: memzero_explicit - make sure to clear out sensitive data random: add and use memzero_explicit() for clearing data
-rw-r--r--crypto/cts.c3
-rw-r--r--crypto/sha1_generic.c2
-rw-r--r--crypto/sha256_generic.c5
-rw-r--r--crypto/sha512_generic.c2
-rw-r--r--crypto/tgr192.c4
-rw-r--r--crypto/vmac.c2
-rw-r--r--crypto/wp512.c8
-rw-r--r--drivers/char/random.c8
-rw-r--r--include/linux/string.h5
-rw-r--r--lib/string.c16
10 files changed, 36 insertions, 19 deletions
diff --git a/crypto/cts.c b/crypto/cts.c
index 042223f..133f0874 100644
--- a/crypto/cts.c
+++ b/crypto/cts.c
@@ -202,7 +202,8 @@ static int cts_cbc_decrypt(struct crypto_cts_ctx *ctx,
/* 5. Append the tail (BB - Ln) bytes of Xn (tmp) to Cn to create En */
memcpy(s + bsize + lastn, tmp + lastn, bsize - lastn);
/* 6. Decrypt En to create Pn-1 */
- memset(iv, 0, sizeof(iv));
+ memzero_explicit(iv, sizeof(iv));
+
sg_set_buf(&sgsrc[0], s + bsize, bsize);
sg_set_buf(&sgdst[0], d, bsize);
err = crypto_blkcipher_decrypt_iv(&lcldesc, sgdst, sgsrc, bsize);
diff --git a/crypto/sha1_generic.c b/crypto/sha1_generic.c
index 4279480..7bb0474 100644
--- a/crypto/sha1_generic.c
+++ b/crypto/sha1_generic.c
@@ -64,7 +64,7 @@ int crypto_sha1_update(struct shash_desc *desc, const u8 *data,
src = data + done;
} while (done + SHA1_BLOCK_SIZE <= len);
- memset(temp, 0, sizeof(temp));
+ memzero_explicit(temp, sizeof(temp));
partial = 0;
}
memcpy(sctx->buffer + partial, src, len - done);
diff --git a/crypto/sha256_generic.c b/crypto/sha256_generic.c
index 0bb5583..65e7b76 100644
--- a/crypto/sha256_generic.c
+++ b/crypto/sha256_generic.c
@@ -211,10 +211,9 @@ 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));
}
-
static int sha224_init(struct shash_desc *desc)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
@@ -317,7 +316,7 @@ static int sha224_final(struct shash_desc *desc, u8 *hash)
sha256_final(desc, D);
memcpy(hash, D, SHA224_DIGEST_SIZE);
- memset(D, 0, SHA256_DIGEST_SIZE);
+ memzero_explicit(D, SHA256_DIGEST_SIZE);
return 0;
}
diff --git a/crypto/sha512_generic.c b/crypto/sha512_generic.c
index 6dde57d..95db671 100644
--- a/crypto/sha512_generic.c
+++ b/crypto/sha512_generic.c
@@ -239,7 +239,7 @@ static int sha384_final(struct shash_desc *desc, u8 *hash)
sha512_final(desc, D);
memcpy(hash, D, 48);
- memset(D, 0, 64);
+ memzero_explicit(D, 64);
return 0;
}
diff --git a/crypto/tgr192.c b/crypto/tgr192.c
index 8740355..3c7af0d 100644
--- a/crypto/tgr192.c
+++ b/crypto/tgr192.c
@@ -612,7 +612,7 @@ static int tgr160_final(struct shash_desc *desc, u8 * out)
tgr192_final(desc, D);
memcpy(out, D, TGR160_DIGEST_SIZE);
- memset(D, 0, TGR192_DIGEST_SIZE);
+ memzero_explicit(D, TGR192_DIGEST_SIZE);
return 0;
}
@@ -623,7 +623,7 @@ static int tgr128_final(struct shash_desc *desc, u8 * out)
tgr192_final(desc, D);
memcpy(out, D, TGR128_DIGEST_SIZE);
- memset(D, 0, TGR192_DIGEST_SIZE);
+ memzero_explicit(D, TGR192_DIGEST_SIZE);
return 0;
}
diff --git a/crypto/vmac.c b/crypto/vmac.c
index 2eb11a3..d84c24b 100644
--- a/crypto/vmac.c
+++ b/crypto/vmac.c
@@ -613,7 +613,7 @@ static int vmac_final(struct shash_desc *pdesc, u8 *out)
}
mac = vmac(ctx->partial, ctx->partial_size, nonce, NULL, ctx);
memcpy(out, &mac, sizeof(vmac_t));
- memset(&mac, 0, sizeof(vmac_t));
+ memzero_explicit(&mac, sizeof(vmac_t));
memset(&ctx->__vmac_ctx, 0, sizeof(struct vmac_ctx));
ctx->partial_size = 0;
return 0;
diff --git a/crypto/wp512.c b/crypto/wp512.c
index 180f1d6..ec64e77 100644
--- a/crypto/wp512.c
+++ b/crypto/wp512.c
@@ -1102,8 +1102,8 @@ static int wp384_final(struct shash_desc *desc, u8 *out)
u8 D[64];
wp512_final(desc, D);
- memcpy (out, D, WP384_DIGEST_SIZE);
- memset (D, 0, WP512_DIGEST_SIZE);
+ memcpy(out, D, WP384_DIGEST_SIZE);
+ memzero_explicit(D, WP512_DIGEST_SIZE);
return 0;
}
@@ -1113,8 +1113,8 @@ static int wp256_final(struct shash_desc *desc, u8 *out)
u8 D[64];
wp512_final(desc, D);
- memcpy (out, D, WP256_DIGEST_SIZE);
- memset (D, 0, WP512_DIGEST_SIZE);
+ memcpy(out, D, WP256_DIGEST_SIZE);
+ memzero_explicit(D, WP512_DIGEST_SIZE);
return 0;
}
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 82759ce..04645c0 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1106,7 +1106,7 @@ static void extract_buf(struct entropy_store *r, __u8 *out)
__mix_pool_bytes(r, hash.w, sizeof(hash.w));
spin_unlock_irqrestore(&r->lock, flags);
- memset(workspace, 0, sizeof(workspace));
+ memzero_explicit(workspace, sizeof(workspace));
/*
* In case the hash function has some recognizable output
@@ -1118,7 +1118,7 @@ static void extract_buf(struct entropy_store *r, __u8 *out)
hash.w[2] ^= rol32(hash.w[2], 16);
memcpy(out, &hash, EXTRACT_SIZE);
- memset(&hash, 0, sizeof(hash));
+ memzero_explicit(&hash, sizeof(hash));
}
/*
@@ -1175,7 +1175,7 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf,
}
/* Wipe data just returned from memory */
- memset(tmp, 0, sizeof(tmp));
+ memzero_explicit(tmp, sizeof(tmp));
return ret;
}
@@ -1218,7 +1218,7 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf,
}
/* Wipe data just returned from memory */
- memset(tmp, 0, sizeof(tmp));
+ memzero_explicit(tmp, sizeof(tmp));
return ret;
}
diff --git a/include/linux/string.h b/include/linux/string.h
index e6edfe5..2e22a2e 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -132,7 +132,7 @@ int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4);
#endif
extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos,
- const void *from, size_t available);
+ const void *from, size_t available);
/**
* strstarts - does @str start with @prefix?
@@ -144,7 +144,8 @@ static inline bool strstarts(const char *str, const char *prefix)
return strncmp(str, prefix, strlen(prefix)) == 0;
}
-extern size_t memweight(const void *ptr, size_t bytes);
+size_t memweight(const void *ptr, size_t bytes);
+void memzero_explicit(void *s, size_t count);
/**
* kbasename - return the last part of a pathname.
diff --git a/lib/string.c b/lib/string.c
index 2fc20aa..1006330 100644
--- a/lib/string.c
+++ b/lib/string.c
@@ -598,6 +598,22 @@ void *memset(void *s, int c, size_t count)
EXPORT_SYMBOL(memset);
#endif
+/**
+ * memzero_explicit - Fill a region of memory (e.g. sensitive
+ * keying data) with 0s.
+ * @s: Pointer to the start of the area.
+ * @count: The size of the area.
+ *
+ * memzero_explicit() doesn't need an arch-specific version as
+ * it just invokes the one of memset() implicitly.
+ */
+void memzero_explicit(void *s, size_t count)
+{
+ memset(s, 0, count);
+ OPTIMIZER_HIDE_VAR(s);
+}
+EXPORT_SYMBOL(memzero_explicit);
+
#ifndef __HAVE_ARCH_MEMCPY
/**
* memcpy - Copy one area of memory to another

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