From 10a525230fb18331dbcfd6a4a7248d76f55c331c Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Mon, 27 Jan 2020 11:02:05 +0900 Subject: [PATCH] Fix some memory leaks and improve restricted token handling on Windows The leaks have been detected by a Coverity run on Windows. No backpatch is done as the leaks are minor. While on it, make restricted token creation more consistent in its error handling by logging an error instead of a warning if missing advapi32.dll, which was missing in the NT4 days. Any modern platform should have this DLL around. Now, if the library is not there, an error is still reported back to the caller, and nothing is done do there is no behavior change done in this commit. Author: Ranier Vilela Discussion: https://postgr.es/m/CAEudQApa9MG0foPkgPX87fipk=vhnF2Xfg+CfUyR08h4R7Mywg@mail.gmail.com --- src/backend/libpq/auth.c | 14 ++++++++++++ src/backend/postmaster/postmaster.c | 6 +++++ src/common/restricted_token.c | 34 +++++++++++++++++++---------- 3 files changed, 42 insertions(+), 12 deletions(-) diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c index 511f891393..bd8c7f5811 100644 --- a/src/backend/libpq/auth.c +++ b/src/backend/libpq/auth.c @@ -1387,6 +1387,13 @@ pg_SSPI_recvauth(Port *port) mtype = pq_getbyte(); if (mtype != 'p') { + if (sspictx != NULL) + { + DeleteSecurityContext(sspictx); + free(sspictx); + } + FreeCredentialsHandle(&sspicred); + /* Only log error if client didn't disconnect. */ if (mtype != EOF) ereport(ERROR, @@ -1402,6 +1409,12 @@ pg_SSPI_recvauth(Port *port) { /* EOF - pq_getmessage already logged error */ pfree(buf.data); + if (sspictx != NULL) + { + DeleteSecurityContext(sspictx); + free(sspictx); + } + FreeCredentialsHandle(&sspicred); return STATUS_ERROR; } @@ -2517,6 +2530,7 @@ InitializeLDAPConnection(Port *port, LDAP **ldap) (errmsg("could not load function _ldap_start_tls_sA in wldap32.dll"), errdetail("LDAP over SSL is not supported on this platform."))); ldap_unbind(*ldap); + FreeLibrary(ldaphandle); return STATUS_ERROR; } diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 7a92dac525..b3986bee75 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -4719,6 +4719,8 @@ retry: if (cmdLine[sizeof(cmdLine) - 2] != '\0') { elog(LOG, "subprocess command line too long"); + UnmapViewOfFile(param); + CloseHandle(paramHandle); return -1; } @@ -4735,6 +4737,8 @@ retry: { elog(LOG, "CreateProcess call failed: %m (error code %lu)", GetLastError()); + UnmapViewOfFile(param); + CloseHandle(paramHandle); return -1; } @@ -4750,6 +4754,8 @@ retry: GetLastError()))); CloseHandle(pi.hProcess); CloseHandle(pi.hThread); + UnmapViewOfFile(param); + CloseHandle(paramHandle); return -1; /* log made by save_backend_variables */ } diff --git a/src/common/restricted_token.c b/src/common/restricted_token.c index 74ba7192a1..a3e0e85fef 100644 --- a/src/common/restricted_token.c +++ b/src/common/restricted_token.c @@ -40,8 +40,8 @@ typedef BOOL (WINAPI * __CreateRestrictedToken) (HANDLE, DWORD, DWORD, PSID_AND_ * * Returns restricted token on success and 0 on failure. * - * On NT4, or any other system not containing the required functions, will - * NOT execute anything. + * On any system not containing the required functions, do nothing + * but still report an error. */ HANDLE CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo) @@ -52,30 +52,36 @@ CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo) HANDLE restrictedToken; SID_IDENTIFIER_AUTHORITY NtAuthority = {SECURITY_NT_AUTHORITY}; SID_AND_ATTRIBUTES dropSids[2]; - __CreateRestrictedToken _CreateRestrictedToken = NULL; + __CreateRestrictedToken _CreateRestrictedToken; HANDLE Advapi32Handle; ZeroMemory(&si, sizeof(si)); si.cb = sizeof(si); Advapi32Handle = LoadLibrary("ADVAPI32.DLL"); - if (Advapi32Handle != NULL) + if (Advapi32Handle == NULL) { - _CreateRestrictedToken = (__CreateRestrictedToken) GetProcAddress(Advapi32Handle, "CreateRestrictedToken"); + pg_log_error("could not load advapi32.dll: error code %lu", + GetLastError()); + return 0; } + _CreateRestrictedToken = (__CreateRestrictedToken) GetProcAddress(Advapi32Handle, "CreateRestrictedToken"); + if (_CreateRestrictedToken == NULL) { - pg_log_warning("cannot create restricted tokens on this platform"); - if (Advapi32Handle != NULL) - FreeLibrary(Advapi32Handle); + pg_log_error("cannot create restricted tokens on this platform: error code %lu", + GetLastError()); + FreeLibrary(Advapi32Handle); return 0; } /* Open the current token to use as a base for the restricted one */ if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &origToken)) { - pg_log_error("could not open process token: error code %lu", GetLastError()); + pg_log_error("could not open process token: error code %lu", + GetLastError()); + FreeLibrary(Advapi32Handle); return 0; } @@ -88,7 +94,10 @@ CreateRestrictedProcess(char *cmd, PROCESS_INFORMATION *processInfo) SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_POWER_USERS, 0, 0, 0, 0, 0, 0, &dropSids[1].Sid)) { - pg_log_error("could not allocate SIDs: error code %lu", GetLastError()); + pg_log_error("could not allocate SIDs: error code %lu", + GetLastError()); + CloseHandle(origToken); + FreeLibrary(Advapi32Handle); return 0; } @@ -171,8 +180,8 @@ get_restricted_token(void) else { /* - * Successfully re-execed. Now wait for child process to capture - * exitcode. + * Successfully re-executed. Now wait for child process to capture + * the exit code. */ DWORD x; @@ -187,6 +196,7 @@ get_restricted_token(void) } exit(x); } + pg_free(cmdline); } #endif }