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| author | Kees Cook <keescook@chromium.org> | 2018-08-08 00:18:38 +0300 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2018-09-04 06:35:03 +0300 |
| commit | b68a7ec1e9a3efac53ae26a1658a553825a2375c (patch) | |
| tree | 6ad87c86f0fc4aeafee091c6d43043876f081d0b /include/crypto | |
| parent | ebf533adc877d9171800bbce77372d8051fc35c2 (diff) | |
| download | linux-b68a7ec1e9a3efac53ae26a1658a553825a2375c.tar.xz | |
crypto: hash - Remove VLA usage
In the quest to remove all stack VLA usage from the kernel[1], this
removes the VLAs in SHASH_DESC_ON_STACK (via crypto_shash_descsize())
by using the maximum allowable size (which is now more clearly captured
in a macro), along with a few other cases. Similar limits are turned into
macros as well.
A review of existing sizes shows that SHA512_DIGEST_SIZE (64) is the
largest digest size and that sizeof(struct sha3_state) (360) is the
largest descriptor size. The corresponding maximums are reduced.
[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'include/crypto')
| -rw-r--r-- | include/crypto/hash.h | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/include/crypto/hash.h b/include/crypto/hash.h index 76e432cab75d..21587011ab0f 100644 --- a/include/crypto/hash.h +++ b/include/crypto/hash.h @@ -151,9 +151,13 @@ struct shash_desc { void *__ctx[] CRYPTO_MINALIGN_ATTR; }; +#define HASH_MAX_DIGESTSIZE 64 +#define HASH_MAX_DESCSIZE 360 +#define HASH_MAX_STATESIZE 512 + #define SHASH_DESC_ON_STACK(shash, ctx) \ char __##shash##_desc[sizeof(struct shash_desc) + \ - crypto_shash_descsize(ctx)] CRYPTO_MINALIGN_ATTR; \ + HASH_MAX_DESCSIZE] CRYPTO_MINALIGN_ATTR; \ struct shash_desc *shash = (struct shash_desc *)__##shash##_desc /** |