From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Fri, 1 Mar 2024 00:21:55 +0000 (+0900)
Subject: icmp6-packet: check the alignment of struct nd_opt_hdr for safety
X-Git-Tag: v256-rc1~692^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bbb2a0fb4129a11df84059cbce326b05f18604c3;p=thirdparty%2Fsystemd.git

icmp6-packet: check the alignment of struct nd_opt_hdr for safety

Addresses https://github.com/systemd/systemd/pull/31492#discussion_r1507481748.
---

diff --git a/src/libsystemd-network/ndisc-protocol.c b/src/libsystemd-network/ndisc-protocol.c
index 39dcdcdfd81..d1f0819e143 100644
--- a/src/libsystemd-network/ndisc-protocol.c
+++ b/src/libsystemd-network/ndisc-protocol.c
@@ -22,6 +22,7 @@ int ndisc_option_parse(
         if (p->raw_size - offset < sizeof(struct nd_opt_hdr))
                 return -EBADMSG;
 
+        assert_cc(alignof(struct nd_opt_hdr) == 1);
         const struct nd_opt_hdr *hdr = (const struct nd_opt_hdr*) (p->raw_packet + offset);
         if (hdr->nd_opt_len == 0)
                 return -EBADMSG;