From 1f17f96b538793a0e665e471f602c6fa490ec167 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 10 Jul 2014 15:59:06 +1000 Subject: [PATCH 12/14] DDF: validate metadata_update size before using it. process_update already checks update->len, for all but the 'magic', prepare_update doesn't at all. So add tests to prepare_update that we don't exceed the buffer. This will consequently protect process_update from looking for a 'magic' which isn't there. Reported-by: Vincent Berg Signed-off-by: NeilBrown --- super-ddf.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/super-ddf.c b/super-ddf.c index 1e43ca2..8957c2e 100644 --- a/super-ddf.c +++ b/super-ddf.c @@ -4914,10 +4914,16 @@ static int ddf_prepare_update(struct supertype *st, * If a malloc is needed, do it here. */ struct ddf_super *ddf = st->sb; - be32 *magic = (be32 *)update->buf; + be32 *magic; + if (update->len < 4) + return 0; + magic = (be32 *)update->buf; if (be32_eq(*magic, DDF_VD_CONF_MAGIC)) { struct vcl *vcl; - struct vd_config *conf = (struct vd_config *) update->buf; + struct vd_config *conf; + if (update->len < (int)sizeof(*conf)) + return 0; + conf = (struct vd_config *) update->buf; if (posix_memalign(&update->space, 512, offsetof(struct vcl, conf) + ddf->conf_rec_len * 512) != 0) { -- 2.0.0