postgres.git / summary / log / commit / refs

commit    8ec00dc5cd70e0e579e9fbf8661bc46f5ccd8078
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Sat Jun 26 18:20:17 2021 +0000

    Remove undesirable libpq dependency on stringinfo.c.
    
    Commit c0cb87fbb unwisely introduced a dependency on the StringInfo
    machinery in fe-connect.c.  We must not use that in libpq, because
    it will do a summary exit(1) if it hits OOM, and that is not
    appropriate behavior for a general-purpose library.  The goal of
    allowing arbitrary line lengths in service files doesn't seem like
    it's worth a lot of effort, so revert back to the previous method
    of using a stack-allocated buffer and failing on buffer overflow.
    
    This isn't an exact revert though.  I kept that patch's refactoring
    to have a single exit path, as that seems cleaner than having each
    error path know what to do to clean up.  Also, I made the fixed-size
    buffer 1024 bytes not 256, just to push off the need for an expandable
    buffer some more.
    
    There is more to do here; in particular the lack of any mechanical
    check for this type of mistake now seems pretty hazardous.  But this
    fix gets us back to the level of robustness we had in v13, anyway.
    
    Discussion: https://postgr.es/m/daeb22ec6ca8ef61e94d766a9b35fb03cabed38e.camel@vmware.com


 src/interfaces/libpq/fe-connect.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 80703698b81..3faf05a7e71 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -28,7 +28,6 @@
 #include "fe-auth.h"
 #include "libpq-fe.h"
 #include "libpq-int.h"
-#include "lib/stringinfo.h"
 #include "mb/pg_wchar.h"
 #include "pg_config_paths.h"
 #include "port/pg_bswap.h"
@@ -5163,7 +5162,7 @@ parseServiceFile(const char *serviceFile,
 				i;
 	FILE	   *f;
 	char	   *line;
-	StringInfoData linebuf;
+	char		buf[1024];
 
 	*group_found = false;
 
@@ -5175,18 +5174,26 @@ parseServiceFile(const char *serviceFile,
 		return 1;
 	}
 
-	initStringInfo(&linebuf);
-
-	while (pg_get_line_buf(f, &linebuf))
+	while ((line = fgets(buf, sizeof(buf), f)) != NULL)
 	{
+		int			len;
+
 		linenr++;
 
-		/* ignore whitespace at end of line, especially the newline */
-		while (linebuf.len > 0 &&
-			   isspace((unsigned char) linebuf.data[linebuf.len - 1]))
-			linebuf.data[--linebuf.len] = '\0';
+		if (strlen(line) >= sizeof(buf) - 1)
+		{
+			appendPQExpBuffer(errorMessage,
+							  libpq_gettext("line %d too long in service file \"%s\"\n"),
+							  linenr,
+							  serviceFile);
+			result = 2;
+			goto exit;
+		}
 
-		line = linebuf.data;
+		/* ignore whitespace at end of line, especially the newline */
+		len = strlen(line);
+		while (len > 0 && isspace((unsigned char) line[len - 1]))
+			line[--len] = '\0';
 
 		/* ignore leading whitespace too */
 		while (*line && isspace((unsigned char) line[0]))
@@ -5303,7 +5310,6 @@ parseServiceFile(const char *serviceFile,
 
 exit:
 	fclose(f);
-	pfree(linebuf.data);
 
 	return result;
 }


[parent: d5a2c413fcdd]