On Thu, Aug 02, 2018 at 03:51:45PM -0700, Kees Cook wrote: > In the quest to remove all stack VLA usage from the kernel[1], this > uses the upper bounds on blocksize. Since this is always a cipher > blocksize, use the existing cipher max blocksize. > > [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx > > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > --- > include/crypto/cbc.h | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/include/crypto/cbc.h b/include/crypto/cbc.h > index f5b8bfc22e6d..47db0aac2ab9 100644 > --- a/include/crypto/cbc.h > +++ b/include/crypto/cbc.h > @@ -113,7 +113,9 @@ static inline int crypto_cbc_decrypt_inplace( > unsigned int bsize = crypto_skcipher_blocksize(tfm); > unsigned int nbytes = walk->nbytes; > u8 *src = walk->src.virt.addr; > - u8 last_iv[bsize]; > + u8 last_iv[MAX_CIPHER_BLOCKSIZE]; > + > + BUG_ON(bsize > sizeof(last_iv)); Ugh, please don't add these BUG_ONs. Add them to the places where the algorithm is created (if they aren't checking that already). Thanks, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
