Restrict file mode creation mask during tmpfile().

Per Coverity.  Back-patch to 9.0 (all supported versions).

Michael Paquier, reviewed (in earlier versions) by Heikki Linnakangas.

diff --git a/src/bin/pg_dump/pg_backup_tar.c b/src/bin/pg_dump/pg_backup_tar.c
index 0e3186caac9d2b72c217cd3df3725dcb3e7cef7d..3e584459c9866f9e24a1884c055d7ac49c748599 100644 (file)
--- a/src/bin/pg_dump/pg_backup_tar.c
+++ b/src/bin/pg_dump/pg_backup_tar.c
@@ -380,8 +380,18 @@ tarOpen(ArchiveHandle *AH, const char *filename, char mode)
    }
    else
    {
+       int         old_umask;
+
        tm = pg_malloc0(sizeof(TAR_MEMBER));
 
+       /*
+        * POSIX does not require, but permits, tmpfile() to restrict file
+        * permissions.  Given an OS crash after we write data, the filesystem
+        * might retain the data but forget tmpfile()'s unlink().  If so, the
+        * file mode protects confidentiality of the data written.
+        */
+       old_umask = umask(S_IRWXG | S_IRWXO);
+
 #ifndef WIN32
        tm->tmpFH = tmpfile();
 #else
@@ -416,6 +426,8 @@ tarOpen(ArchiveHandle *AH, const char *filename, char mode)
        if (tm->tmpFH == NULL)
            exit_horribly(modulename, "could not generate temporary file name: %s\n", strerror(errno));
 
+       umask(old_umask);
+
 #ifdef HAVE_LIBZ
 
        if (AH->compression != 0)