This is the mail archive of the
cygwin-patches
mailing list for the Cygwin project.
[PATCH] Cygwin: pty: Prevent potential errno overwriting.
- From: Takashi Yano <takashi dot yano at nifty dot ne dot jp>
- To: cygwin-patches at cygwin dot com
- Cc: Takashi Yano <takashi dot yano at nifty dot ne dot jp>
- Date: Mon, 10 Feb 2020 20:42:45 +0900
- Subject: [PATCH] Cygwin: pty: Prevent potential errno overwriting.
- Dkim-filter: OpenDKIM Filter v2.10.3 conuserg-06.nifty.com 01ABglRt029161
- In push_to_pcon_screenbuffer(), open() and ioctl() are called.
Since push_to_pcon_screenbuffer() is called in read() and write(),
errno which is set in read() and write() code may be overwritten
in open() or ioctl() call. This patch prevent this situation.
---
winsup/cygwin/fhandler_tty.cc | 3 +++
1 file changed, 3 insertions(+)
diff --git a/winsup/cygwin/fhandler_tty.cc b/winsup/cygwin/fhandler_tty.cc
index 260776a56..cfd4b1c44 100644
--- a/winsup/cygwin/fhandler_tty.cc
+++ b/winsup/cygwin/fhandler_tty.cc
@@ -1412,10 +1412,13 @@ fhandler_pty_slave::push_to_pcon_screenbuffer (const char *ptr, size_t len,
while (!GetConsoleMode (get_output_handle (), &dwMode))
{
termios_printf ("GetConsoleMode failed, %E");
+ int errno_save = errno;
/* Re-open handles */
this->open (0, 0);
/* Fix pseudo console window size */
this->ioctl (TIOCSWINSZ, &get_ttyp ()->winsize);
+ if (errno != errno_save)
+ set_errno (errno_save);
if (++retry_count > 3)
goto cleanup;
}
--
2.21.0