On Wed, Jun 20, 2018 at 12:04:01PM -0700, Kees Cook wrote: > In the quest to remove all stack VLA usage from the kernel[1], this > uses the newly defined max digest size macro. Also adds a sanity-check > at use-time. > > [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@xxxxxxxxxxxxxx > > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> > --- > drivers/md/dm-verity-fec.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c > index 684af08d0747..0dfcc52835bc 100644 > --- a/drivers/md/dm-verity-fec.c > +++ b/drivers/md/dm-verity-fec.c > @@ -212,12 +212,15 @@ static int fec_read_bufs(struct dm_verity *v, struct dm_verity_io *io, > struct dm_verity_fec_io *fio = fec_io(io); > u64 block, ileaved; > u8 *bbuf, *rs_block; > - u8 want_digest[v->digest_size]; > + u8 want_digest[AHASH_MAX_DIGESTSIZE]; > unsigned n, k; > > if (neras) > *neras = 0; > > + if (WARN_ON(v->digest_size < sizeof(want_digest))) > + return -EINVAL; How about verifying digest_size in the ahash API when algorithms are registered? Cheers, -- Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
