On Sep 18, 7:31 pm, jmor...@coverity.com ("Jesse Morris") wrote:
> The following bug has been logged online:
>
> Bug reference:      5065
> Logged by:          Jesse Morris
> Email address:      jmor...@coverity.com
> PostgreSQL version: 8.3.7, 8.4.1
> Operating system:   Windows Server 2003 R2
> Description:        pg_ctl start fails as administrator, with "could not
> locate matching postgres executable"
> Details:
>
> I am logged in as domain\jmorris, a member of the local Administrators
> group.
>
...
>
> From cmd.exe:
> initdb.exe works fine.
> pg_ctl start complains "FATAL: postgres - could not locate matching postgres
> executable"
>
> Instrumentation and investigation reveals that the failure is in
> find_other_exec (exec.c) as the error text implies, but ultimately in
> pipe_read_line; CreatePipe fails with error 5 (Access Denied).  
...

I went back to the version that supposedly initially fixed this issue,
but I couldn't get it to work either.  So I think the DACL adjustment
code was always broken.  The DACL stuff that both Cygwin and Active
Perl use to simulate *nix file permissions masks this error, so any
test framework that uses them would get false negatives on this bug.
Since these DACLs are inheritable, a workaround is to run pg_ctl as a
child process of Active Perl or Cygwin.   The comments indicated
pg_ctl & initdb were already trying to do the same thing themselves
(that is, add the current user to the DACLs) but it didn't actually
work on any of the systems I tried it on.

I think that a number of other people have seen this bug; search for
"FATAL: postgres - could not locate matching postgres executable."
But that message is so misleading is probably why it seems nobody has
properly diagnosed it as a permissions issue before.  I didn't do
anything to fix pg_ctl's error reporting.  :D

The patch:

------begin patch------

diff -rup unfixed/postgresql-8.4.1/src/bin/initdb/initdb.c fixed/
postgresql-8.4.1/src/bin/initdb/initdb.c
--- unfixed/postgresql-8.4.1/src/bin/initdb/initdb.c    2009-06-11
07:49:07.000000000 -0700
+++ fixed/postgresql-8.4.1/src/bin/initdb/initdb.c      2009-10-15
16:31:12.651226900 -0700
@@ -2392,6 +2392,10 @@ CreateRestrictedProcess(char *cmd, PROCE
                fprintf(stderr, "Failed to create restricted token: %lu\n",
GetLastError());
                return 0;
        }
+
+#ifndef __CYGWIN__
+    AddUserToTokenDacl(restrictedToken);
+#endif

        if (!CreateProcessAsUser(restrictedToken,
                                                         NULL,
@@ -2409,11 +2413,7 @@ CreateRestrictedProcess(char *cmd, PROCE
                fprintf(stderr, "CreateProcessAsUser failed: %lu\n", 
GetLastError
());
                return 0;
        }
-
-#ifndef __CYGWIN__
-       AddUserToDacl(processInfo->hProcess);
-#endif
-
+
        return ResumeThread(processInfo->hThread);
 }
 #endif
Only in fixed/postgresql-8.4.1/src/bin/initdb: initdb.c.bak
diff -rup unfixed/postgresql-8.4.1/src/bin/pg_ctl/pg_ctl.c fixed/
postgresql-8.4.1/src/bin/pg_ctl/pg_ctl.c
--- unfixed/postgresql-8.4.1/src/bin/pg_ctl/pg_ctl.c    2009-09-01
19:40:59.000000000 -0700
+++ fixed/postgresql-8.4.1/src/bin/pg_ctl/pg_ctl.c      2009-10-15
16:31:00.096971600 -0700
@@ -1389,7 +1389,10 @@ CreateRestrictedProcess(char *cmd, PROCE
                write_stderr("Failed to create restricted token: %lu\n",
GetLastError());
                return 0;
        }
-
+#ifndef __CYGWIN__
+       AddUserToTokenDacl(restrictedToken);
+#endif
+
        r = CreateProcessAsUser(restrictedToken, NULL, cmd, NULL, NULL,
TRUE, CREATE_SUSPENDED, NULL, NULL, &si, processInfo);

        Kernel32Handle = LoadLibrary("KERNEL32.DLL");
@@ -1488,9 +1491,6 @@ CreateRestrictedProcess(char *cmd, PROCE
                }
        }

-#ifndef __CYGWIN__
-       AddUserToDacl(processInfo->hProcess);
-#endif

        CloseHandle(restrictedToken);

Only in fixed/postgresql-8.4.1/src/bin/pg_ctl: pg_ctl.c.bak
diff -rup unfixed/postgresql-8.4.1/src/include/port.h fixed/
postgresql-8.4.1/src/include/port.h
--- unfixed/postgresql-8.4.1/src/include/port.h 2009-06-11
07:49:08.000000000 -0700
+++ fixed/postgresql-8.4.1/src/include/port.h   2009-10-15
14:02:36.860635900 -0700
@@ -81,7 +81,7 @@ extern int find_other_exec(const char *a

 /* Windows security token manipulation (in exec.c) */
 #ifdef WIN32
-extern BOOL AddUserToDacl(HANDLE hProcess);
+extern BOOL AddUserToTokenDacl(HANDLE hToken);
 #endif


diff -rup unfixed/postgresql-8.4.1/src/port/exec.c fixed/
postgresql-8.4.1/src/port/exec.c
--- unfixed/postgresql-8.4.1/src/port/exec.c    2009-06-11
07:49:15.000000000 -0700
+++ fixed/postgresql-8.4.1/src/port/exec.c      2009-10-15
16:02:04.352805300 -0700
@@ -664,11 +664,10 @@ set_pglocale_pgservice(const char *argv0
 #ifdef WIN32

 /*
- * AddUserToDacl(HANDLE hProcess)
+ * AddUserToTokenDacl(HANDLE hToken)
  *
- * This function adds the current user account to the default DACL
- * which gets attached to the restricted token used when we create
- * a restricted process.
+ * This function adds the current user account to the restricted
+ * token used when we create a restricted process.
  *
  * This is required because of some security changes in Windows
  * that appeared in patches to XP/2K3 and in Vista/2008.
@@ -681,13 +680,13 @@ set_pglocale_pgservice(const char *argv0
  * and CreateProcess() calls when running as Administrator.
  *
  * This function fixes this problem by modifying the DACL of the
- * specified process and explicitly re-adding the current user
account.
- * This is still secure because the Administrator account inherits
it's
- * privileges from the Administrators group - it doesn't have any of
- * it's own.
+ * token the process will use, and explicitly re-adding the current
+ * user account.  This is still secure because the Administrator
account
+ * inherits it's privileges from the Administrators group - it
doesn't
+ * have any of its own.
  */
 BOOL
-AddUserToDacl(HANDLE hProcess)
+AddUserToTokenDacl(HANDLE hToken)
 {
        int                     i;
        ACL_SIZE_INFORMATION asi;
@@ -695,7 +694,6 @@ AddUserToDacl(HANDLE hProcess)
        DWORD           dwNewAclSize;
        DWORD           dwSize = 0;
        DWORD           dwTokenInfoLength = 0;
-       HANDLE          hToken = NULL;
        PACL            pacl = NULL;
        PSID            psidUser = NULL;
        TOKEN_DEFAULT_DACL tddNew;
@@ -703,13 +701,6 @@ AddUserToDacl(HANDLE hProcess)
        TOKEN_INFORMATION_CLASS tic = TokenDefaultDacl;
        BOOL            ret = FALSE;

-       /* Get the token for the process */
-       if (!OpenProcessToken(hProcess, TOKEN_QUERY | TOKEN_ADJUST_DEFAULT,
&hToken))
-       {
-               log_error("could not open process token: %lu", GetLastError());
-               goto cleanup;
-       }
-
        /* Figure out the buffer size for the DACL info */
        if (!GetTokenInformation(hToken, tic, (LPVOID) NULL,
dwTokenInfoLength, &dwSize))
        {
@@ -785,8 +776,8 @@ AddUserToDacl(HANDLE hProcess)
        }

        /* Add the new ACE for the current user */
-       if (!AddAccessAllowedAce(pacl, ACL_REVISION, GENERIC_ALL, psidUser))
-       {
+       if (!AddAccessAllowedAceEx(pacl, ACL_REVISION, OBJECT_INHERIT_ACE,
GENERIC_ALL, psidUser))
+       {
                log_error("could not add access allowed ACE: %lu", 
GetLastError());
                goto cleanup;
        }
@@ -812,9 +803,6 @@ cleanup:
        if (ptdd)
                LocalFree((HLOCAL) ptdd);

-       if (hToken)
-               CloseHandle(hToken);
-
        return ret;
 }

diff -rup unfixed/postgresql-8.4.1/src/test/regress/pg_regress.c fixed/
postgresql-8.4.1/src/test/regress/pg_regress.c
--- unfixed/postgresql-8.4.1/src/test/regress/pg_regress.c      2009-06-11
07:49:15.000000000 -0700
+++ fixed/postgresql-8.4.1/src/test/regress/pg_regress.c        2009-10-15
14:03:51.609110000 -0700
@@ -1021,6 +1021,10 @@ spawn_process(const char *cmdline)
        cmdline2 = malloc(strlen(cmdline) + 8);
        sprintf(cmdline2, "cmd /c %s", cmdline);

+#ifndef __CYGWIN__
+       AddUserToTokenDacl(restrictedToken);
+#endif
+
        if (!CreateProcessAsUser(restrictedToken,
                                                         NULL,
                                                         cmdline2,
@@ -1038,10 +1042,6 @@ spawn_process(const char *cmdline)
                exit_nicely(2);
        }

-#ifndef __CYGWIN__
-       AddUserToDacl(pi.hProcess);
-#endif
-
        free(cmdline2);

        ResumeThread(pi.hThread);
------end patch------

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