crypto: s5p - deal gracefully with bogus input sizes

The s5p skcipher driver returns -EINVAL for zero length inputs, which
deviates from the behavior of the generic ECB template, and causes fuzz
tests to fail. In cases where the input is not a multiple of the AES
block size (and the chaining mode is not CTR), it prints an error to
the kernel log, which is a thing we usually try to avoid in response
to situations that can be triggered by unprivileged users.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Kamil Konieczny <k.konieczny@partner.samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Ard Biesheuvel 2019-08-19 17:22:25 +03:00 committed by Herbert Xu
parent 735177ca14
commit 84a0b00aa4

View file

@ -2056,9 +2056,12 @@ static int s5p_aes_crypt(struct ablkcipher_request *req, unsigned long mode)
struct s5p_aes_ctx *ctx = crypto_ablkcipher_ctx(tfm); struct s5p_aes_ctx *ctx = crypto_ablkcipher_ctx(tfm);
struct s5p_aes_dev *dev = ctx->dev; struct s5p_aes_dev *dev = ctx->dev;
if (!req->nbytes)
return 0;
if (!IS_ALIGNED(req->nbytes, AES_BLOCK_SIZE) && if (!IS_ALIGNED(req->nbytes, AES_BLOCK_SIZE) &&
((mode & FLAGS_AES_MODE_MASK) != FLAGS_AES_CTR)) { ((mode & FLAGS_AES_MODE_MASK) != FLAGS_AES_CTR)) {
dev_err(dev->dev, "request size is not exact amount of AES blocks\n"); dev_dbg(dev->dev, "request size is not exact amount of AES blocks\n");
return -EINVAL; return -EINVAL;
} }