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| author | Kees Cook <keescook@chromium.org> | 2018-08-07 14:18:35 -0700 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2018-09-04 11:35:03 +0800 |
| commit | 3bdd23f886c08a0d649c535e1e2cf083ec600036 (patch) | |
| tree | 80ea091af3f8ed5646cf53a58cb485966c9fff66 /crypto/xcbc.c | |
| parent | 578bdaabd015b9b164842c3e8ace9802f38e7ecc (diff) | |
| download | linux-3bdd23f886c08a0d649c535e1e2cf083ec600036.tar.gz linux-3bdd23f886c08a0d649c535e1e2cf083ec600036.tar.bz2 linux-3bdd23f886c08a0d649c535e1e2cf083ec600036.zip | |
crypto: xcbc - Remove VLA usage
In the quest to remove all stack VLA usage from the kernel[1], this uses
the maximum blocksize and adds a sanity check. For xcbc, the blocksize
must always be 16, so use that, since it's already being enforced during
instantiation.
[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 'crypto/xcbc.c')
| -rw-r--r-- | crypto/xcbc.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/crypto/xcbc.c b/crypto/xcbc.c index 25c75af50d3f..c055f57fab11 100644 --- a/crypto/xcbc.c +++ b/crypto/xcbc.c @@ -57,15 +57,17 @@ struct xcbc_desc_ctx { u8 ctx[]; }; +#define XCBC_BLOCKSIZE 16 + static int crypto_xcbc_digest_setkey(struct crypto_shash *parent, const u8 *inkey, unsigned int keylen) { unsigned long alignmask = crypto_shash_alignmask(parent); struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent); - int bs = crypto_shash_blocksize(parent); u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); int err = 0; - u8 key1[bs]; + u8 key1[XCBC_BLOCKSIZE]; + int bs = sizeof(key1); if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen))) return err; @@ -212,7 +214,7 @@ static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb) return PTR_ERR(alg); switch(alg->cra_blocksize) { - case 16: + case XCBC_BLOCKSIZE: break; default: goto out_put_alg; |