log: prevent stack smashing

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/log.c b/src/lxc/log.c
index e05cbde64bd2a6c3008652d087d5edb4bed937d2..cdff1750624536f9569844974e0754fcefa770c3 100644 (file)
--- a/src/lxc/log.c
+++ b/src/lxc/log.c
@@ -228,7 +228,8 @@ static int log_append_logfile(const struct lxc_log_appender *appender,
 
        if ((size_t)n < (sizeof(buffer) - 1))
                n += vsnprintf(buffer + n, sizeof(buffer) - n, event->fmt, *event->vap);
-       else
+
+       if ((size_t)n >= sizeof(buffer))
                n = sizeof(buffer) - 1;
 
        buffer[n] = '\n';