public inbox for cygwin-cvs@sourceware.org
help / color / mirror / Atom feed
* [newlib-cygwin] Cygwin: console: Fix segfault on shared_console_info access.
@ 2020-02-24 18:41 Corinna Vinschen
0 siblings, 0 replies; only message in thread
From: Corinna Vinschen @ 2020-02-24 18:41 UTC (permalink / raw)
To: cygwin-cvs
https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=17528b9d2c3147f5de0f604fc2702b2e0010c533
commit 17528b9d2c3147f5de0f604fc2702b2e0010c533
Author: Takashi Yano <takashi.yano@nifty.ne.jp>
Date: Tue Feb 25 01:12:16 2020 +0900
Cygwin: console: Fix segfault on shared_console_info access.
- Accessing shared_console_info before initialization causes access
violation because it is a NULL pointer. The cause of the problem
reported in https://cygwin.com/ml/cygwin/2020-02/msg00197.html is
this NULL pointer access in request_xterm_mode_output() when it is
called from close(). This patch makes sure that shared_console_info
is not NULL before calling request_xterm_mode_output().
Diff:
---
winsup/cygwin/fhandler_console.cc | 23 +++++++++++------------
winsup/cygwin/release/3.1.5 | 4 ++++
2 files changed, 15 insertions(+), 12 deletions(-)
diff --git a/winsup/cygwin/fhandler_console.cc b/winsup/cygwin/fhandler_console.cc
index 42040a9..328424a 100644
--- a/winsup/cygwin/fhandler_console.cc
+++ b/winsup/cygwin/fhandler_console.cc
@@ -1159,18 +1159,17 @@ fhandler_console::close ()
acquire_output_mutex (INFINITE);
- if (shared_console_info && myself->pid == con.owner &&
- wincap.has_con_24bit_colors () && !con_is_legacy)
- request_xterm_mode_output (false);
-
- /* Restore console mode if this is the last closure. */
- OBJECT_BASIC_INFORMATION obi;
- NTSTATUS status;
- status = NtQueryObject (get_handle (), ObjectBasicInformation,
- &obi, sizeof obi, NULL);
- if (NT_SUCCESS (status) && obi.HandleCount == 1)
- if (wincap.has_con_24bit_colors ())
- request_xterm_mode_output (false);
+ if (shared_console_info && wincap.has_con_24bit_colors ())
+ {
+ /* Restore console mode if this is the last closure. */
+ OBJECT_BASIC_INFORMATION obi;
+ NTSTATUS status;
+ status = NtQueryObject (get_handle (), ObjectBasicInformation,
+ &obi, sizeof obi, NULL);
+ if ((NT_SUCCESS (status) && obi.HandleCount == 1)
+ || myself->pid == con.owner)
+ request_xterm_mode_output (false);
+ }
release_output_mutex ();
diff --git a/winsup/cygwin/release/3.1.5 b/winsup/cygwin/release/3.1.5
index 796fd21..e34fdb8 100644
--- a/winsup/cygwin/release/3.1.5
+++ b/winsup/cygwin/release/3.1.5
@@ -5,3 +5,7 @@ Bug Fixes:
Don't move cursor to the right in case of a NUL character in the console
output stream, this is not backed by terminfo.
Addresses: https://cygwin.com/ml/cygwin/2020-02/msg00162.html
+
+- Fix a segfault when starting, e.g., mintty from a bash in a console
+ running xterm emulation.
+ Addresses: https://cygwin.com/ml/cygwin/2020-02/msg00197.html
^ permalink raw reply [flat|nested] only message in thread
only message in thread, other threads:[~2020-02-24 18:41 UTC | newest]
Thread overview: (only message) (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-24 18:41 [newlib-cygwin] Cygwin: console: Fix segfault on shared_console_info access Corinna Vinschen
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).