ospf6d: fix out of bounds write in ospf6_prefix_apply_mask
ospf6_prefix_apply_mask would write one byte beyond the 4/8/12
bytes allocated for prefixes of length 32/64/96.
based on report and patch by Jon Andersson <jon.andersson@thales.no>
Reported-by: Jon Andersson <jon.andersson@thales.no>
Signed-off-by: David Lamparter <equinox@diac24.net>
diff --git a/ospf6d/ospf6_proto.c b/ospf6d/ospf6_proto.c
index c792aa4..d011601 100644
--- a/ospf6d/ospf6_proto.c
+++ b/ospf6d/ospf6_proto.c
@@ -42,11 +42,10 @@
return;
}
- if (index == 16)
- return;
-
- pnt[index] &= mask;
- index ++;
+ /* nonzero mask means no check for this byte because if it contains
+ * prefix bits it must be there for us to write */
+ if (mask)
+ pnt[index++] &= mask;
while (index < OSPF6_PREFIX_SPACE (op->prefix_length))
pnt[index++] = 0;