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 Cc: Alasdair Kergon <agk@xxxxxxxxxx> Cc: Mike Snitzer <snitzer@xxxxxxxxxx> Cc: dm-devel@xxxxxxxxxx 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..fe5cfd1a5fa5 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; + /* * read each of the rsn data blocks that are part of the RS block, and * interleave contents to available bufs -- 2.17.1
