From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Wed, 15 Nov 2023 17:17:22 +0000 (+0900)
Subject: dhcp: do not trigger assertion by malformed messages
X-Git-Tag: v255-rc3~59^2~1
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c0b927eb3ad800062fc6d6d38a4bf678f897974e;p=thirdparty%2Fsystemd.git

dhcp: do not trigger assertion by malformed messages

This also changes error code from -ENODATA -> -EBADMSG,
as we received bad message in that case.

Prompted by #30029.
---

diff --git a/src/libsystemd-network/sd-dhcp-lease.c b/src/libsystemd-network/sd-dhcp-lease.c
index 4925fa8f193..4e3be98a33a 100644
--- a/src/libsystemd-network/sd-dhcp-lease.c
+++ b/src/libsystemd-network/sd-dhcp-lease.c
@@ -931,7 +931,10 @@ int dhcp_lease_parse_search_domains(const uint8_t *option, size_t len, char ***d
         int r;
 
         assert(domains);
-        assert_return(option && len > 0, -ENODATA);
+        assert(option || len == 0);
+
+        if (len == 0)
+                return -EBADMSG;
 
         while (pos < len) {
                 _cleanup_free_ char *name = NULL;
diff --git a/src/libsystemd-network/test-sd-dhcp-lease.c b/src/libsystemd-network/test-sd-dhcp-lease.c
index 3eea1b0d9b8..910b622191c 100644
--- a/src/libsystemd-network/test-sd-dhcp-lease.c
+++ b/src/libsystemd-network/test-sd-dhcp-lease.c
@@ -60,8 +60,8 @@ TEST(dhcp_lease_parse_search_domains_no_data) {
         _cleanup_strv_free_ char **domains = NULL;
         static const uint8_t optionbuf[3] = {0, 0, 0};
 
-        assert_se(dhcp_lease_parse_search_domains(NULL, 0, &domains) == -ENODATA);
-        assert_se(dhcp_lease_parse_search_domains(optionbuf, 0, &domains) == -ENODATA);
+        assert_se(dhcp_lease_parse_search_domains(NULL, 0, &domains) == -EBADMSG);
+        assert_se(dhcp_lease_parse_search_domains(optionbuf, 0, &domains) == -EBADMSG);
 }
 
 TEST(dhcp_lease_parse_search_domains_loops) {