1 files changed, 5 insertions, 4 deletions

diff --git a/libbb/copyfd.c b/libbb/copyfd.c
index c1962e3c6..0b850884b 100644
--- a/libbb/copyfd.c
+++ b/libbb/copyfd.c
@@ -29,11 +29,13 @@ static ssize_t bb_full_fd_action(int src_fd, int dst_fd, size_t size)
         RESERVE_CONFIG_BUFFER(buffer,BUFSIZ);
 
         if (src_fd < 0) goto out;
-
         while (!size || total < size)
         {
-                ssize_t wrote, xread = (size && size < BUFSIZ) ? size : BUFSIZ;
-                xread = safe_read(src_fd, buffer, xread);
+                ssize_t wrote, xread;
+                
+                xread = safe_read(src_fd, buffer,
+                                (!size || size - total > BUFSIZ) ? BUFSIZ : size - total);
+
                 if (xread > 0) {
                         /* A -1 dst_fd means we need to fake it... */
                         wrote = (dst_fd < 0) ? xread : bb_full_write(dst_fd, buffer, xread);
@@ -42,7 +44,6 @@ static ssize_t bb_full_fd_action(int src_fd, int dst_fd, size_t size)
                                 break;
                         }
                         total += wrote;
-                        size -= wrote;
                 } else if (xread < 0) {
                         bb_perror_msg(bb_msg_read_error);
                         break;