From f975120d20d51ca11217e4abbf16cc51ab8c9290 Mon Sep 17 00:00:00 2001 From: Takashi Yano Date: Sat, 22 Oct 2022 14:05:40 +0900 Subject: [PATCH 38/N] Cygwin: pty: Fix 'Bad address' error when running 'cmd.exe /c dir' - If the command executed is 'cmd.exe /c [...]', runpath in spawn.cc will be NULL. In this case, is_console_app(runpath) check causes access violation. This case also the command executed is obviously console app., therefore, treat it as console app to fix this issue. Addresses: https://github.com/msys2/msys2-runtime/issues/108 This is a backport of 08281cf4cc (Cygwin: pty: Fix 'Bad address' error when running 'cmd.exe /c dir', 2022-10-22). The original patch that was replaced by this commit had this additional information that is now sadly lost in Cygwin's history: In 2b4f986e49 (Cygwin: pty: Treat *.bat and *.cmd as a non-cygwin console app., 2022-07-31), we introduced a bug fix that specifically looks for a suffix of the command's file name. However, that file name might be set to `NULL`, namely when `null_app_name == true`, which is the case when we detected a command-line `cmd /c [...]`. But the commit mentioned above did not account for that possibility, instead assuming that it always has to check the file name for a `.bat` or `.cmd` suffix. As a consequence, `cmd /c [...]` invocations are completely broken in v3.3.6, resulting in a `Bad address` error. Signed-off-by: Johannes Schindelin --- winsup/cygwin/spawn.cc | 2 ++ 1 file changed, 2 insertions(+) diff --git a/winsup/cygwin/spawn.cc b/winsup/cygwin/spawn.cc index bc9dc5a..9636109 100644 --- a/winsup/cygwin/spawn.cc +++ b/winsup/cygwin/spawn.cc @@ -198,6 +198,8 @@ handle (int fd, bool writing) static bool is_console_app (WCHAR *filename) { + if (filename == NULL) + return true; /* The command executed is command.com or cmd.exe. */ HANDLE h; const int id_offset = 92; h = CreateFileW (filename, GENERIC_READ, FILE_SHARE_READ,