From: Siddhesh Poyarekar <siddhesh@redhat.com>
Date: Tue, 14 Oct 2014 15:35:33 +0000 (+0530)
Subject: Fix infinite loop in check_pf (BZ #12926)
X-Git-Tag: glibc-2.21~497
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fda389c8f0311dd5786be91a7b54b9f935fcafa1;p=thirdparty%2Fglibc.git

Fix infinite loop in check_pf (BZ #12926)

The recvmsg could return 0 under some conditions and cause the
make_request function to be stuck in an infinite loop.

Thank you Jim King <jim.king@simplivity.com> for posting Paul's patch
on the list.
---

diff --git a/ChangeLog b/ChangeLog
index e40ba1f346c..73db0841e14 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-10-14  Paul Pluzhnikov  <ppluzhnikov@google.com>
+
+	[BZ #12926]
+	* sysdeps/unix/sysv/linux/check_pf.c (make_request): Avoid
+	infinite loop when __recvmsg returns 0.
+
 2014-10-10  Joseph Myers  <joseph@codesourcery.com>
 
 	* CANCEL-FCT-WAIVE: Remove file.
diff --git a/NEWS b/NEWS
index accc1441d6b..987f3066556 100644
--- a/NEWS
+++ b/NEWS
@@ -9,7 +9,7 @@ Version 2.21
 
 * The following bugs are resolved with this release:
 
-  6652, 14171, 17266, 17363, 17370, 17371, 17411, 17460.
+  6652, 12926, 14171, 17266, 17363, 17370, 17371, 17411, 17460.
 
 Version 2.20
 
diff --git a/sysdeps/unix/sysv/linux/check_pf.c b/sysdeps/unix/sysv/linux/check_pf.c
index c7fd9b0376a..976f249e209 100644
--- a/sysdeps/unix/sysv/linux/check_pf.c
+++ b/sysdeps/unix/sysv/linux/check_pf.c
@@ -180,7 +180,7 @@ make_request (int fd, pid_t pid)
 	};
 
       ssize_t read_len = TEMP_FAILURE_RETRY (__recvmsg (fd, &msg, 0));
-      if (read_len < 0)
+      if (read_len <= 0)
 	goto out_fail2;
 
       if (msg.msg_flags & MSG_TRUNC)