Fix failure to advance content pointer in sendFileWithContent.

robertmhaas · robertmhaas · commit 8b5ba2f3f40a · 2022-12-12T10:33:02.000-05:00
If sendFileWithContent were used to send a file larger than the bbsink buffer size, this would result in corruption. The only files that are sent via sendFileWithContent are the backup label file, the tablespace map file, and .done files for WAL segments included in the backup. Of these, it seems that only the tablespace_map file can become large enough to cause a problem, and then only if you have a lot of tablespaces. If you do have that situation, you might end up with a corrupted tablespace_map file, which would be bad. My commit bef47ff introduced this problem. Report and patch by Antonin Houska. Discussion: http://postgr.es/m/15764.1670528645@antos
diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c
@@ -1057,6 +1057,7 @@ sendFileWithContent(bbsink *sink, const char *filename, const char *content,
 		memcpy(sink->bbs_buffer, content, nbytes);
 		bbsink_archive_contents(sink, nbytes);
 		bytes_done += nbytes;
+		content += nbytes;
 	}
 
 	_tarWritePadding(sink, len);

Original file line number	Diff line number	Diff line change
`@@ -1057,6 +1057,7 @@ sendFileWithContent(bbsink sink, const char filename, const char *content,`
`1057`	`1057`	`memcpy(sink->bbs_buffer, content, nbytes);`
`1058`	`1058`	`bbsink_archive_contents(sink, nbytes);`
`1059`	`1059`	`bytes_done += nbytes;`
	`1060`	`+ content += nbytes;`
`1060`	`1061`	`}`
`1061`	`1062`
`1062`	`1063`	`_tarWritePadding(sink, len);`