crypto: simd - correctly take reqsize of wrapped skcipher into account

The simd wrapper's skcipher request context structure consists
of a single subrequest whose size is taken from the subordinate
skcipher. However, in simd_skcipher_init(), the reqsize that is
retrieved is not from the subordinate skcipher but from the
cryptd request structure, whose size is completely unrelated to
the actual wrapped skcipher.

Reported-by: Qian Cai <cai@gmx.us>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Qian Cai <cai@gmx.us>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 3 insertions, 2 deletions

diff --git a/crypto/simd.c b/crypto/simd.c
index ea7240be3001..78e8d037ae2b 100644
--- a/crypto/simd.c
+++ b/crypto/simd.c
@@ -124,8 +124,9 @@ static int simd_skcipher_init(struct crypto_skcipher *tfm)
 
         ctx->cryptd_tfm = cryptd_tfm;
 
-        reqsize = sizeof(struct skcipher_request);
-        reqsize += crypto_skcipher_reqsize(&cryptd_tfm->base);
+        reqsize = crypto_skcipher_reqsize(cryptd_skcipher_child(cryptd_tfm));
+        reqsize = max(reqsize, crypto_skcipher_reqsize(&cryptd_tfm->base));
+        reqsize += sizeof(struct skcipher_request);
 
         crypto_skcipher_set_reqsize(tfm, reqsize);