From 40c79e979ea8dbbf2262297865754910f8d704c0 Mon Sep 17 00:00:00 2001 From: Kyle Evans Date: Tue, 23 Jul 2024 15:25:46 -0500 Subject: [PATCH] route: avoid overlapping strcpy Passing overlapping buffers to strcpy yields an undefined result, so let's avoid it. The copy doesn't really need to happen anyways, we can just point to the domain part of the hostname. This was discovered with _FORTIFY_SOURCE. Sponsored by: Klara, Inc. Sponsored by: Stormshield Reviewed by: allanjude, emaste, imp, melifaro (all previous version) (cherry picked from commit 158f319428c10143ce2ffe766416207c75578931) --- sbin/route/route.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/sbin/route/route.c b/sbin/route/route.c index 7cf2bf84255..ad7a906bc14 100644 --- a/sbin/route/route.c +++ b/sbin/route/route.c @@ -107,8 +107,8 @@ static u_long rtm_inits; static uid_t uid; static int defaultfib; static int numfibs; -static char domain[MAXHOSTNAMELEN + 1]; -static bool domain_initialized; +static char domain_storage[MAXHOSTNAMELEN + 1]; +static const char *domain; static char rt_line[NI_MAXHOST]; static char net_line[MAXHOSTNAMELEN + 1]; @@ -594,14 +594,16 @@ routename(struct sockaddr *sa) const char *cp; int n; - if (!domain_initialized) { - domain_initialized = true; - if (gethostname(domain, MAXHOSTNAMELEN) == 0 && - (cp = strchr(domain, '.'))) { - domain[MAXHOSTNAMELEN] = '\0'; - (void)strcpy(domain, cp + 1); - } else - domain[0] = '\0'; + if (domain == NULL) { + if (gethostname(domain_storage, + sizeof(domain_storage) - 1) == 0 && + (cp = strchr(domain_storage, '.')) != NULL) { + domain_storage[sizeof(domain_storage) - 1] = '\0'; + domain = cp + 1; + } else { + domain_storage[0] = '\0'; + domain = domain_storage; + } } /* If the address is zero-filled, use "default". */