slirp: check len against dhcp options array end
While parsing dhcp options string in 'dhcp_decode', if an options'
length 'len' appeared towards the end of 'bp_vend' array, ensuing
read could lead to an OOB memory access issue. Add check to avoid it.
This is CVE-2017-11434.
Reported-by: Reno Robert <renorobert@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
diff --git a/bootp.c b/bootp.c
index baa6380..810da0c 100644
--- a/bootp.c
+++ b/bootp.c
@@ -129,6 +129,9 @@
if (p >= p_end)
break;
len = *p++;
+ if (p + len > p_end) {
+ break;
+ }
DPRINTF("dhcp: tag=%d len=%d\n", tag, len);
switch (tag) {
