From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 3 Aug 2025 17:01:17 +0000 (-0400)
Subject: Take a little more care in set_backtrace().
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5c8eda1f72a2b0a8c48ada9b872eb5ef581f7c81;p=thirdparty%2Fpostgresql.git

Take a little more care in set_backtrace().

Coverity complained that the "errtrace" string is leaked if we return
early because backtrace_symbols fails.  Another criticism that could
be leveled at this is that not providing any hint of what happened is
user-unfriendly.  Fix that.

The odds of a leak here are small, and typically it wouldn't matter
anyway since the leak will be in ErrorContext which will soon get
reset.  So I'm not feeling a need to back-patch.
---

diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 47af743990f..afce1a8e1f0 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -1128,12 +1128,15 @@ set_backtrace(ErrorData *edata, int num_skip)
 
 		nframes = backtrace(buf, lengthof(buf));
 		strfrms = backtrace_symbols(buf, nframes);
-		if (strfrms == NULL)
-			return;
-
-		for (int i = num_skip; i < nframes; i++)
-			appendStringInfo(&errtrace, "\n%s", strfrms[i]);
-		free(strfrms);
+		if (strfrms != NULL)
+		{
+			for (int i = num_skip; i < nframes; i++)
+				appendStringInfo(&errtrace, "\n%s", strfrms[i]);
+			free(strfrms);
+		}
+		else
+			appendStringInfoString(&errtrace,
+								   "insufficient memory for backtrace generation");
 	}
 #else
 	appendStringInfoString(&errtrace,