From f7797747fc8fa6e5d5513e6871ee56f7cf91c51c Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 14 Jun 2022 18:16:46 -0400 Subject: [PATCH] Avoid ecpglib core dump with out-of-order operations. If an application executed operations like EXEC SQL PREPARE without having first established a database connection, it could get a core dump instead of the expected clean failure. This occurred because we did "pthread_getspecific(actual_connection_key)" without ever having initialized the TSD key actual_connection_key. The results of that are probably platform-specific, but at least on Linux it often leads to a crash. To fix, add calls to ecpg_pthreads_init() in the code paths that might use actual_connection_key uninitialized. It's harmless (and hopefully inexpensive) to do that more than once. Per bug #17514 from Okano Naoki. The problem's ancient, so back-patch to all supported branches. Discussion: https://postgr.es/m/17514-edd4fad547c5692c@postgresql.org --- src/interfaces/ecpg/ecpglib/connect.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/src/interfaces/ecpg/ecpglib/connect.c b/src/interfaces/ecpg/ecpglib/connect.c index 1e27238856..96b29237b5 100644 --- a/src/interfaces/ecpg/ecpglib/connect.c +++ b/src/interfaces/ecpg/ecpglib/connect.c @@ -40,6 +40,8 @@ ecpg_get_connection_nr(const char *connection_name) if ((connection_name == NULL) || (strcmp(connection_name, "CURRENT") == 0)) { #ifdef ENABLE_THREAD_SAFETY + ecpg_pthreads_init(); /* ensure actual_connection_key is valid */ + ret = pthread_getspecific(actual_connection_key); /* @@ -47,8 +49,7 @@ ecpg_get_connection_nr(const char *connection_name) * connection and hope the user knows what they're doing (i.e. using * their own mutex to protect that connection from concurrent accesses */ - /* if !ret then we got the connection from TSD */ - if (NULL == ret) + if (ret == NULL) /* no TSD connection, going for global */ ret = actual_connection; #else @@ -78,6 +79,8 @@ ecpg_get_connection(const char *connection_name) if ((connection_name == NULL) || (strcmp(connection_name, "CURRENT") == 0)) { #ifdef ENABLE_THREAD_SAFETY + ecpg_pthreads_init(); /* ensure actual_connection_key is valid */ + ret = pthread_getspecific(actual_connection_key); /* @@ -85,8 +88,7 @@ ecpg_get_connection(const char *connection_name) * connection and hope the user knows what they're doing (i.e. using * their own mutex to protect that connection from concurrent accesses */ - /* if !ret then we got the connection from TSD */ - if (NULL == ret) + if (ret == NULL) /* no TSD connection here either, using global */ ret = actual_connection; #else