In the quest to remove all stack VLA usage from the kernel[1], this uses the maximum blocksize and adds a sanity check. [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- crypto/xcbc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/crypto/xcbc.c b/crypto/xcbc.c index 25c75af50d3f..016481b1f3ba 100644 --- a/crypto/xcbc.c +++ b/crypto/xcbc.c @@ -65,7 +65,10 @@ static int crypto_xcbc_digest_setkey(struct crypto_shash *parent, int bs = crypto_shash_blocksize(parent); u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); int err = 0; - u8 key1[bs]; + u8 key1[CRYPTO_ALG_MAX_BLOCKSIZE]; + + if (WARN_ON(bs > sizeof(key1))) + return -EINVAL; if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen))) return err; -- 2.17.1
