From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Thu, 25 Jul 2019 14:22:17 +0000 (-0300)
Subject: Get new entropy on each attempt __gen_tempname (BZ #15813)
X-Git-Tag: changelog-ends-here~161
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e1df30fbc2e2167a982c0e77a7ebee28f4dd0800;p=thirdparty%2Fglibc.git

Get new entropy on each attempt __gen_tempname (BZ #15813)

This is missing bit for fully fix BZ#15813 (the other two were fixed
by 359653aaacad463).

Checked on x86_64-linux-gnu.

	[BZ #15813]
	sysdeps/posix/tempname.c (__gen_tempname): get entrypy on each
	attempt.
---

diff --git a/ChangeLog b/ChangeLog
index cdb9e148817..17918a129c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2019-08-01  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
+
+	[BZ #15813]
+	sysdeps/posix/tempname.c (__gen_tempname): get entropy on each
+	attempt.
+
 2019-08-01  Carlos O'Donell <carlos@redhat.com>
 
 	* version.h (RELEASE): Set to "stable".
diff --git a/sysdeps/posix/tempname.c b/sysdeps/posix/tempname.c
index de346949b2b..310df3c4ca0 100644
--- a/sysdeps/posix/tempname.c
+++ b/sysdeps/posix/tempname.c
@@ -186,7 +186,6 @@ __gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
 {
   int len;
   char *XXXXXX;
-  uint64_t value;
   unsigned int count;
   int fd = -1;
   int save_errno = errno;
@@ -218,13 +217,13 @@ __gen_tempname (char *tmpl, int suffixlen, int flags, int kind)
   /* This is where the Xs start.  */
   XXXXXX = &tmpl[len - 6 - suffixlen];
 
-  /* Get some more or less random data.  */
-  RANDOM_BITS (value);
-  value ^= (uint64_t)__getpid () << 32;
-
-  for (count = 0; count < attempts; value += 7777, ++count)
+  uint64_t pid = (uint64_t) __getpid () << 32;
+  for (count = 0; count < attempts; ++count)
     {
-      uint64_t v = value;
+      uint64_t v;
+      /* Get some more or less random data.  */
+      RANDOM_BITS (v);
+      v ^= pid;
 
       /* Fill in the random bits.  */
       XXXXXX[0] = letters[v % 62];