dhcp/dhcp-4.3.6-options_overflow.patch
2018-03-01 10:25:39 +01:00

42 lines
1.3 KiB
Diff

diff --git a/common/options.c b/common/options.c
index 83e0384..8a1deca 100644
--- a/common/options.c
+++ b/common/options.c
@@ -1672,7 +1672,8 @@ format_min_length(format, oc)
/* Format the specified option so that a human can easily read it. */
-
+/* Maximum pretty printed size */
+#define MAX_OUTPUT_SIZE 32*1024
const char *pretty_print_option (option, data, len, emit_commas, emit_quotes)
struct option *option;
const unsigned char *data;
@@ -1680,8 +1681,9 @@ const char *pretty_print_option (option, data, len, emit_commas, emit_quotes)
int emit_commas;
int emit_quotes;
{
- static char optbuf [32768]; /* XXX */
- static char *endbuf = &optbuf[sizeof(optbuf)];
+ /* We add 128 byte pad so we don't have to add checks everywhere. */
+ static char optbuf [MAX_OUTPUT_SIZE + 128]; /* XXX */
+ static char *endbuf = optbuf + MAX_OUTPUT_SIZE;
int hunksize = 0;
int opthunk = 0;
int hunkinc = 0;
@@ -2132,7 +2134,14 @@ const char *pretty_print_option (option, data, len, emit_commas, emit_quotes)
log_error ("Unexpected format code %c",
fmtbuf [j]);
}
+
op += strlen (op);
+ if (op >= endbuf) {
+ log_error ("Option data exceeds"
+ " maximum size %d", MAX_OUTPUT_SIZE);
+ return ("<error>");
+ }
+
if (dp == data + len)
break;
if (j + 1 < numelem && comma != ':')