Fix use of free in walsender error handling after a sysid mismatch.

hlinnaka · hlinnaka · commit a7a3e71c8592 · 2014-05-06T15:16:51.000+03:00
Found via valgrind. The bug exists since the introduction of the walsender,
so backpatch to 9.0.

Andres Freund
diff --git a/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c b/src/backend/replication/libpqwalreceiver/libpqwalreceiver.c
@@ -151,6 +151,7 @@ libpqrcv_identify_system(TimeLineID *primary_tli)
 			 GetSystemIdentifier());
 	if (strcmp(primary_sysid, standby_sysid) != 0)
 	{
+		primary_sysid = pstrdup(primary_sysid);
 		PQclear(res);
 		ereport(ERROR,
 				(errmsg("database system identifier differs between the primary and standby"),

Original file line number	Diff line number	Diff line change
`@@ -151,6 +151,7 @@ libpqrcv_identify_system(TimeLineID *primary_tli)`
`151`	`151`	`GetSystemIdentifier());`
`152`	`152`	`if (strcmp(primary_sysid, standby_sysid) != 0)`
`153`	`153`	`{`
	`154`	`+ primary_sysid = pstrdup(primary_sysid);`
`154`	`155`	`PQclear(res);`
`155`	`156`	`ereport(ERROR,`
`156`	`157`	`(errmsg("database system identifier differs between the primary and standby"),`