rpms/kernel/F-10 ecryptfs-prevent-lower-dentry-from-going-negative-during-unlink.patch, NONE, 1.1.2.1 kernel.spec, 1.1206.2.97, 1.1206.2.98

[Chuck Ebbert]

Author: cebbert

Update of /cvs/pkgs/rpms/kernel/F-10
In directory cvs1.fedora.phx.redhat.com:/tmp/cvs-serv16692

Modified Files:
      Tag: private-fedora-10-2_6_27
	kernel.spec 
Added Files:
      Tag: private-fedora-10-2_6_27
	ecryptfs-prevent-lower-dentry-from-going-negative-during-unlink.patch 
Log Message:
eCryptfs: Prevent lower dentry from going negative during unlink (CVE-2009-2908)

ecryptfs-prevent-lower-dentry-from-going-negative-during-unlink.patch:
 inode.c |    2 ++
 1 file changed, 2 insertions(+)

--- NEW FILE ecryptfs-prevent-lower-dentry-from-going-negative-during-unlink.patch ---
>From 9c2d2056647790c5034d722bd24e9d913ebca73c Mon Sep 17 00:00:00 2001
From: Tyler Hicks <tyhicks at linux.vnet.ibm.com>
Date: Tue, 22 Sep 2009 12:52:17 -0500
Subject: eCryptfs: Prevent lower dentry from going negative during unlink
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

From: Tyler Hicks <tyhicks at linux.vnet.ibm.com>

commit 9c2d2056647790c5034d722bd24e9d913ebca73c upstream.

When calling vfs_unlink() on the lower dentry, d_delete() turns the
dentry into a negative dentry when the d_count is 1.  This eventually
caused a NULL pointer deref when a read() or write() was done and the
negative dentry's d_inode was dereferenced in
ecryptfs_read_update_atime() or ecryptfs_getxattr().

Placing mutt's tmpdir in an eCryptfs mount is what initially triggered
the oops and I was able to reproduce it with the following sequence:

open("/tmp/upper/foo", O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW, 0600) = 3
link("/tmp/upper/foo", "/tmp/upper/bar") = 0
unlink("/tmp/upper/foo")                = 0
open("/tmp/upper/bar", O_RDWR|O_CREAT|O_NOFOLLOW, 0600) = 4
unlink("/tmp/upper/bar")                = 0
write(4, "eCryptfs test\n"..., 14 <unfinished ...>
+++ killed by SIGKILL +++

https://bugs.launchpad.net/ecryptfs/+bug/387073

Reported-by: Loïc Minier <loic.minier at canonical.com>
Cc: Serge Hallyn <serue at us.ibm.com>
Cc: Dave Kleikamp <shaggy at linux.vnet.ibm.com>
Cc: ecryptfs-devel at lists.launchpad.net
Signed-off-by: Tyler Hicks <tyhicks at linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>

---
 fs/ecryptfs/inode.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -443,6 +443,7 @@ static int ecryptfs_unlink(struct inode 
 	struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
 	struct dentry *lower_dir_dentry;
 
+	dget(lower_dentry);
 	lower_dir_dentry = lock_parent(lower_dentry);
 	rc = vfs_unlink(lower_dir_inode, lower_dentry);
 	if (rc) {
@@ -456,6 +457,7 @@ static int ecryptfs_unlink(struct inode 
 	d_drop(dentry);
 out_unlock:
 	unlock_dir(lower_dir_dentry);
+	dput(lower_dentry);
 	return rc;
 }
 


Index: kernel.spec
===================================================================
RCS file: /cvs/pkgs/rpms/kernel/F-10/kernel.spec,v
retrieving revision 1.1206.2.97
retrieving revision 1.1206.2.98
diff -u -p -r1.1206.2.97 -r1.1206.2.98
--- kernel.spec	5 Oct 2009 21:42:17 -0000	1.1206.2.97
+++ kernel.spec	7 Oct 2009 11:14:39 -0000	1.1206.2.98
@@ -792,6 +792,9 @@ Patch15200: appletalk-fix-skb-leak-when-
 # fix stack randomization (#526882)
 Patch15300: x86-increase-min_gap-to-include-randomized-stack.patch
 
+# CVE-2009-2908
+Patch15400: ecryptfs-prevent-lower-dentry-from-going-negative-during-unlink.patch
+
 %endif
 
 BuildRoot: %{_tmppath}/kernel-%{KVERREL}-root
@@ -1433,6 +1436,9 @@ ApplyPatch appletalk-fix-skb-leak-when-i
 # backport of stack randomization fix from 2.6.31.2
 ApplyPatch x86-increase-min_gap-to-include-randomized-stack.patch
 
+# CVE-2009-2908
+ApplyPatch ecryptfs-prevent-lower-dentry-from-going-negative-during-unlink.patch
+
 # END OF PATCH APPLICATIONS
 
 %endif
@@ -2008,6 +2014,9 @@ fi
 %kernel_variant_files -k vmlinux %{with_kdump} kdump
 
 %changelog
+* Wed Oct 07 2009  Chuck Ebbert <cebbert at redhat.com>  2.6.27.36-170.2.98
+- eCryptfs: Prevent lower dentry from going negative during unlink (CVE-2009-2908)
+
 * Mon Oct 05 2009  Chuck Ebbert <cebbert at redhat.com>  2.6.27.36-170.2.97
 - Linux 2.6.27.36