From e92ba41e9b4aff335ef8c95f89791dee2e942532 Mon Sep 17 00:00:00 2001
From: Roy Marples <roy@marples.name>
Date: Tue, 30 Dec 2025 07:52:43 +0000
Subject: [PATCH] options: Ensure that an overly long bitflag string does not
 crash

Fixes #573.
---
 src/if-options.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/if-options.c b/src/if-options.c
index 9ac9f0b8..b55e65d6 100644
--- a/src/if-options.c
+++ b/src/if-options.c
@@ -2130,6 +2130,10 @@ parse_option(struct dhcpcd_ctx *ctx, const char *ifname, struct if_options *ifo,
 		ndop->var = np;
 		if (bp) {
 			dl = strlen(bp);
+			if (dl > sizeof(ndop->bitflags)) {
+				logwarnx("bitflag string too long %s", bp);
+				dl = sizeof(ndop->bitflags);
+			}
 			memcpy(ndop->bitflags, bp, dl);
 			memset(ndop->bitflags + dl, 0,
 			    sizeof(ndop->bitflags) - dl);