From 946219115d00c6ae658afcf538249e721e6bd600 Mon Sep 17 00:00:00 2001 From: Frank Lichtenheld Date: Fri, 22 Sep 2023 18:04:41 +0200 Subject: [PATCH] buffer: use memcpy in buf_catrunc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since we use strlen() to determine the length and then check it ourselves, there is really no point in using strncpy. But the compiler might complain that we use the output of strlen() for the length of strncpy which is usually a sign for bugs: error: ‘strncpy’ specified bound depends on the length of the source argument [-Werror=stringop-overflow=] Warning was at least triggered for mingw-gcc version 10-win32 20220113. Also change the type of len to size_t which avoids potential problems with signed overflow. v2: - make len size_t and change code to avoid any theoretical overflows - remove useless casts v3: - fix off-by-one introduced by v2 %) v4: - ignore unsigned overflow to simplify code Change-Id: If4a67adac4d2e870fd719b58075d39efcd67c671 Signed-off-by: Frank Lichtenheld Acked-by: Antonio Quartulli Acked-by: Heiko Hund Acked-by: Gert Doering (cherry picked from commit c89a97e449baaf60924a362555d35184f188a646) Message-Id: <20230922160441.167168-1-frank@lichtenheld.com> URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg27085.html Signed-off-by: Gert Doering --- src/openvpn/buffer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/openvpn/buffer.c b/src/openvpn/buffer.c index d099795be87..7725438e4ec 100644 --- a/src/openvpn/buffer.c +++ b/src/openvpn/buffer.c @@ -316,10 +316,10 @@ buf_catrunc(struct buffer *buf, const char *str) { if (buf_forward_capacity(buf) <= 1) { - int len = (int) strlen(str) + 1; + size_t len = strlen(str) + 1; if (len < buf_forward_capacity_total(buf)) { - strncpynt((char *)(buf->data + buf->capacity - len), str, len); + memcpy(buf->data + buf->capacity - len, str, len); } } }