[ovs-dev] [PATCH] ofp-util: Fix buffer overrread in ofputil_pull_queue_get_config_reply10().

[Ben Pfaff]

msg->size isn't the relevant measurement here because we're only supposed
to read 'len' bytes.  Reading more than that causes 'len' to underflow to a
large number at the end of the loop.

Reported-by: Bhargava Shastry <bshastry at sec.t-labs.tu-berlin.de>
Signed-off-by: Ben Pfaff <blp at ovn.org>
---
 lib/ofp-util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/ofp-util.c b/lib/ofp-util.c
index bdf89b6c3017..f05ca398c13e 100644
--- a/lib/ofp-util.c
+++ b/lib/ofp-util.c
@@ -2610,7 +2610,7 @@ ofputil_pull_queue_get_config_reply10(struct ofpbuf *msg,
 
         hdr = ofpbuf_at_assert(msg, 0, sizeof *hdr);
         prop_len = ntohs(hdr->len);
-        if (prop_len < sizeof *hdr || prop_len > msg->size || prop_len % 8) {
+        if (prop_len < sizeof *hdr || prop_len > len || prop_len % 8) {
             return OFPERR_OFPBRC_BAD_LEN;
         }
 
-- 
2.10.2