diff --git a/quota-3.17-quotactl_null_corruption.patch b/quota-3.17-quotactl_null_corruption.patch
new file mode 100644
index 0000000..3deaf9f
--- /dev/null
+++ b/quota-3.17-quotactl_null_corruption.patch
@@ -0,0 +1,25 @@
+Avoid memory corruption of NULL address.
+
+Backport of
+<https://sourceforge.net/tracker/?func=detail&aid=2996418&group_id=18136&atid=118136>
+and n+2nd CVS commit.
+
+diff --git a/quotasys.c b/quotasys.c
+index 9a7f440..0a4a609 100644
+--- a/quotasys.c
++++ b/quotasys.c
+@@ -707,9 +707,12 @@ void init_kernel_interface(void)
+ 	kernel_formats = 0;
+ 	if (!stat("/proc/fs/xfs/stat", &st))
+ 		kernel_formats |= (1 << QF_XFS);
+-	else
+-		if (!quotactl(QCMD(Q_XGETQSTAT, 0), NULL, 0, NULL) || (errno != EINVAL && errno != ENOSYS))
++	else {
++		fs_quota_stat_t dummy;
++
++		if (!quotactl(QCMD(Q_XGETQSTAT, 0), "/dev/root", 0, (void *)&dummy) || (errno != EINVAL && errno != ENOSYS))
+ 			kernel_formats |= (1 << QF_XFS);
++	}
+ 	/* Detect new kernel interface; Assume generic interface unless we can prove there is not one... */
+ 	if (!stat("/proc/sys/fs/quota", &st) || errno != ENOENT) {
+ 		kernel_iface = IFACE_GENERIC;
diff --git a/quota.spec b/quota.spec
index 08d022e..4190385 100644
--- a/quota.spec
+++ b/quota.spec
@@ -5,7 +5,7 @@ Name: quota
 Summary: System administration tools for monitoring users' disk usage
 Epoch: 1
 Version: 3.17
-Release: 11%{?dist}
+Release: 12%{?dist}
 License: BSD and GPLv2+
 URL: http://sourceforge.net/projects/linuxquota/
 Group: System Environment/Base
@@ -15,7 +15,7 @@ Conflicts: kernel < 2.4
 BuildRequires: e2fsprogs-devel gettext tcp_wrappers-devel nss-devel
 BuildRequires: openldap-devel openssl-devel dbus-devel libnl-devel
 Source0: http://downloads.sourceforge.net/linuxquota/%{name}-%{version}.tar.gz
-Patch0:	quota-3.06-warnquota.patch
+Patch0: quota-3.06-warnquota.patch
 Patch1: quota-3.06-no-stripping.patch
 Patch2: quota-3.06-man-page.patch
 Patch3: quota-3.06-pie.patch
@@ -24,10 +24,12 @@ Patch5: quota-3.16-helpoption.patch
 Patch6: quota-3.16-quotaoffhelp.patch
 Patch7: quota-3.17-quotactlmanpage.patch
 Patch8: quota-3.17-ftbfs.patch
+# Bug #528581, remove in upstream 4.00
+Patch9: quota-3.17-quotactl_null_corruption.patch
 
 %description
 The quota package contains system administration tools for monitoring
-and limiting user and or group disk usage per filesystem.
+and limiting user and or group disk usage per file system.
 
 %package devel
 Summary: Development files for quota
@@ -36,7 +38,7 @@ Requires: quota =  %{epoch}:%{version}-%{release}
 
 %description devel
 The quota package contains system administration tools for monitoring
-and limiting user and or group disk usage per filesystem.
+and limiting user and or group disk usage per file system.
 
 This package contains development header files for implementing quotas
 on remote machines.
@@ -55,6 +57,7 @@ on remote machines.
 %patch6 -p1 -b .usage
 %patch7 -p1 -b .quotactlman
 %patch8 -p1
+%patch9 -p1 -b .quotactl_null_corruption
 
 #fix typos/mistakes in localized documentation
 for pofile in $(find ./po/*.p*)
@@ -117,6 +120,11 @@ rm -rf %{buildroot}
 %attr(0644,root,root) %{_mandir}/man3/*
 
 %changelog
+* Tue May 10 2010 Petr Pisar <ppisar@redhat.com> 1:3.17-12
+- Prevent corruptive read/write from/to NULL address in rpc.rquotad
+  (Resolves #528581, example in #532342)
+- Fix spelling in summary
+
 * Fri Mar 12 2010 Daniel Novotny <dnovotny@redhat.com> 1:3.17-11
 - the require from previous fix deleted altogether (it will
   be resolved automatically)
@@ -125,7 +133,7 @@ rm -rf %{buildroot}
 - Requires: e2fsprogs changed to e2fsprogs-libs (#570005)
 
 * Tue Feb 23 2010 Daniel Novotny <dnovotny@redhat.com> 1:3.17-9
-- fix #565124 -  FTBFS quota-3.17-8.fc13: ImplicitDSOLinking
+- fix #565124 - FTBFS quota-3.17-8.fc13: ImplicitDSOLinking
 
 * Mon Sep 29 2009 Ondrej Vasik <ovasik@redhat.com> 1:3.17-8
 - add buildrequires for quota_nld, enable-netlink to build