[3.8.y.z extended stable] Patch "xfs: ioctl check for capabilities in the current user namespace" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    xfs: ioctl check for capabilities in the current user namespace

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.27.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From c23ab20680d3f5443d4711c01c286591d8ac6c7a Mon Sep 17 00:00:00 2001
From: Dwight Engen <dwight.engen at oracle.com>
Date: Thu, 15 Aug 2013 14:08:00 -0400
Subject: xfs: ioctl check for capabilities in the current user namespace

commit fd5e2aa8653665ae1cc60f7aca1069abdbcad3f6 upstream.

Use inode_capable() to check if SUID|SGID bits should be cleared to match
similar check in inode_change_ok().

The check for CAP_LINUX_IMMUTABLE was not modified since all other file
systems also check against init_user_ns rather than current_user_ns.

Only allow changing of projid from init_user_ns.

Reviewed-by: Dave Chinner <dchinner at redhat.com>
Reviewed-by: Gao feng <gaofeng at cn.fujitsu.com>
Signed-off-by: Dwight Engen <dwight.engen at oracle.com>
Signed-off-by: Ben Myers <bpm at sgi.com>
[ kamal: 3.8-stable prereq for
  23adbe1 fs,userns: Change inode_capable to capable_wrt_inode_uidgid ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 fs/xfs/xfs_ioctl.c  | 11 +++++++++--
 kernel/capability.c |  1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index cdaef2d..ec74a78 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -976,15 +976,22 @@ xfs_ioctl_setattr(
 	 * to the file owner ID, except in cases where the
 	 * CAP_FSETID capability is applicable.
 	 */
-	if (current_fsuid() != ip->i_d.di_uid && !capable(CAP_FOWNER)) {
+	if (!inode_owner_or_capable(VFS_I(ip))) {
 		code = XFS_ERROR(EPERM);
 		goto error_return;
 	}

 	/*
 	 * Do a quota reservation only if projid is actually going to change.
+	 * Only allow changing of projid from init_user_ns since it is a
+	 * non user namespace aware identifier.
 	 */
 	if (mask & FSX_PROJID) {
+		if (current_user_ns() != &init_user_ns) {
+			code = XFS_ERROR(EINVAL);
+			goto error_return;
+		}
+
 		if (XFS_IS_QUOTA_RUNNING(mp) &&
 		    XFS_IS_PQUOTA_ON(mp) &&
 		    xfs_get_projid(ip) != fa->fsx_projid) {
@@ -1098,7 +1105,7 @@ xfs_ioctl_setattr(
 		 * cleared upon successful return from chown()
 		 */
 		if ((ip->i_d.di_mode & (S_ISUID|S_ISGID)) &&
-		    !capable(CAP_FSETID))
+		    !inode_capable(VFS_I(ip), CAP_FSETID))
 			ip->i_d.di_mode &= ~(S_ISUID|S_ISGID);

 		/*
diff --git a/kernel/capability.c b/kernel/capability.c
index f6c2ce5..a4b6744 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -464,3 +464,4 @@ bool inode_capable(const struct inode *inode, int cap)

 	return ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid);
 }
+EXPORT_SYMBOL(inode_capable);
--
1.9.1