While the existing code is not wrong and will never cause an overflow, it will copy (on a too-long source string) "maxlen" bytes to dest, and then overwrite the last byte just copied with "0" - which causes a warning in gcc 9 about filling the target buffer "up to the end, with no room for a trailing 0 anymore".
Reducing the maximum bytes-to-be-copied to "maxlen -1", because the last byte will be stamped with 0 anyway. v2: do not ASSERT() on "maxlen == 0", but move the strncpy() call inside the if() clause - so "just do nothing" on maxlen == 0, as before. Signed-off-by: Gert Doering <[email protected]> --- src/openvpn/buffer.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/openvpn/buffer.h b/src/openvpn/buffer.h index a4fe6f9b..e8b83a5e 100644 --- a/src/openvpn/buffer.h +++ b/src/openvpn/buffer.h @@ -347,9 +347,9 @@ buf_set_read(struct buffer *buf, const uint8_t *data, int size) static inline void strncpynt(char *dest, const char *src, size_t maxlen) { - strncpy(dest, src, maxlen); if (maxlen > 0) { + strncpy(dest, src, maxlen-1); dest[maxlen - 1] = 0; } } -- 2.21.0 _______________________________________________ Openvpn-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/openvpn-devel
