From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2155) id 7B44B3857811; Tue, 14 Sep 2021 15:06:24 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7B44B3857811 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Corinna Vinschen To: cygwin-cvs@sourceware.org Subject: [newlib-cygwin] Cygwin: pipes: call nt_create with handle references X-Act-Checkin: newlib-cygwin X-Git-Author: Corinna Vinschen X-Git-Refname: refs/heads/master X-Git-Oldrev: 8653eb1df330880aabc909f7eed043122bbeaf7d X-Git-Newrev: ea9c0bbedcd43a6f7f90936e2626270e2c8e591a Message-Id: <20210914150624.7B44B3857811@sourceware.org> Date: Tue, 14 Sep 2021 15:06:24 +0000 (GMT) X-BeenThere: cygwin-cvs@cygwin.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Cygwin core component git logs List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Sep 2021 15:06:24 -0000 https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=ea9c0bbedcd43a6f7f90936e2626270e2c8e591a commit ea9c0bbedcd43a6f7f90936e2626270e2c8e591a Author: Corinna Vinschen Date: Fri Sep 3 10:57:21 2021 +0200 Cygwin: pipes: call nt_create with handle references ...to avoid potential pointer mishandling. Signed-off-by: Corinna Vinschen Diff: --- winsup/cygwin/fhandler_pipe.cc | 55 ++++++++++++++++++------------------------ 1 file changed, 23 insertions(+), 32 deletions(-) diff --git a/winsup/cygwin/fhandler_pipe.cc b/winsup/cygwin/fhandler_pipe.cc index 1cf27333e..608c67c32 100644 --- a/winsup/cygwin/fhandler_pipe.cc +++ b/winsup/cygwin/fhandler_pipe.cc @@ -660,7 +660,7 @@ fhandler_pipe::create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w, simplicity, nt_create will omit the 'open_mode' and 'name' parameters, which aren't needed for our purposes. */ -static int nt_create (LPSECURITY_ATTRIBUTES, PHANDLE, PHANDLE, DWORD, +static int nt_create (LPSECURITY_ATTRIBUTES, HANDLE &, HANDLE &, DWORD, int64_t *); int @@ -671,7 +671,7 @@ fhandler_pipe::create (fhandler_pipe *fhs[2], unsigned psize, int mode) int res = -1; int64_t unique_id; - int ret = nt_create (sa, &r, &w, psize, &unique_id); + int ret = nt_create (sa, r, w, psize, &unique_id); if (ret) __seterrno_from_win_error (ret); else if ((fhs[0] = (fhandler_pipe *) build_fh_dev (*piper_dev)) == NULL) @@ -718,7 +718,7 @@ fhandler_pipe::create (fhandler_pipe *fhs[2], unsigned psize, int mode) } static int -nt_create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w, +nt_create (LPSECURITY_ATTRIBUTES sa_ptr, HANDLE &r, HANDLE &w, DWORD psize, int64_t *unique_id) { NTSTATUS status; @@ -729,10 +729,8 @@ nt_create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w, LARGE_INTEGER timeout; /* Default to error. */ - if (r) - *r = NULL; - if (w) - *w = NULL; + r = NULL; + w = NULL; status = fhandler_base::npfs_handle (npfsh); if (!NT_SUCCESS (status)) @@ -760,7 +758,7 @@ nt_create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w, Retrying will probably never be necessary, but we want to be as robust as possible. */ DWORD err = 0; - while (r && !*r) + while (!r) { static volatile ULONG pipe_unique_id; LONG id = InterlockedIncrement ((LONG *) &pipe_unique_id); @@ -779,7 +777,7 @@ nt_create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w, npfsh, sa_ptr->lpSecurityDescriptor); timeout.QuadPart = -500000; - status = NtCreateNamedPipeFile (r, access, &attr, &io, + status = NtCreateNamedPipeFile (&r, access, &attr, &io, FILE_SHARE_READ | FILE_SHARE_WRITE, FILE_CREATE, 0, pipe_type, FILE_PIPE_BYTE_STREAM_MODE, @@ -787,7 +785,7 @@ nt_create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w, if (NT_SUCCESS (status)) { - debug_printf ("pipe read handle %p", *r); + debug_printf ("pipe read handle %p", r); err = 0; break; } @@ -800,49 +798,42 @@ nt_create (LPSECURITY_ATTRIBUTES sa_ptr, PHANDLE r, PHANDLE w, /* The pipe is already open with compatible parameters. Pick a new name and retry. */ debug_printf ("pipe busy, retrying"); - *r = NULL; + r = NULL; break; case STATUS_ACCESS_DENIED: /* The pipe is already open with incompatible parameters. Pick a new name and retry. */ debug_printf ("pipe access denied, retrying"); - *r = NULL; + r = NULL; break; default: { __seterrno_from_nt_status (status); err = GetLastError (); debug_printf ("failed, %E"); - *r = INVALID_HANDLE_VALUE; + r = INVALID_HANDLE_VALUE; } } } if (err) { - *r = NULL; + r = NULL; return err; } - if (!w) - debug_printf ("pipe write handle NULL"); - else - { - debug_printf ("NtOpenFile: name %S", &pipename); - - access = GENERIC_WRITE | FILE_READ_ATTRIBUTES | SYNCHRONIZE; - status = NtOpenFile (w, access, &attr, &io, 0, 0); - if (!NT_SUCCESS (status)) - { - DWORD err = GetLastError (); - debug_printf ("NtOpenFile failed, r %p, %E", r); - if (r) - NtClose (*r); - *w = NULL; - return err; - } + debug_printf ("NtOpenFile: name %S", &pipename); - debug_printf ("pipe write handle %p", *w); + access = GENERIC_WRITE | FILE_READ_ATTRIBUTES | SYNCHRONIZE; + status = NtOpenFile (&w, access, &attr, &io, 0, 0); + if (!NT_SUCCESS (status)) + { + DWORD err = GetLastError (); + debug_printf ("NtOpenFile failed, r %p, %E", r); + if (r) + NtClose (r); + w = NULL; + return err; } /* Success. */