proto_ipv4: Make netsniff detect and properly handle some malformed p…

…ackets Entails the potential integer underflow of a signed integer. Signed-off-by: Nathaniel Ferguson <[email protected]> Signed-off-by: Tobias Klauser <[email protected]>
netsniff-ng · May 4, 2020 · 9d71c0f · 9d71c0f
1 parent 21b9cc3
commit 9d71c0f
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/proto_ipv4.c b/proto_ipv4.c
@@ -154,7 +154,7 @@ static void ipv4(struct pkt_buff *pkt)
  * check and handle that
  */
  opt_len = *(++opt);
- if (opt_len > opts_len) {
+ if (opt_len < 2 || opt_len > opts_len) {
  tprintf(", Len (%zd, invalid) ]\n", opt_len);
  goto out;
  } else