[ 3.5.y.z extended stable ] Patch "xfs: kill suid/sgid through the truncate path." has been added to staging queue

[Luis Henriques]

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

    xfs: kill suid/sgid through the truncate path.

to the linux-3.5.y-queue branch of the 3.5.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-3.5.y-queue

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

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 28cc501f86b082db8a8d828b217d4b984af6541b Mon Sep 17 00:00:00 2001
From: Dave Chinner <dchinner at redhat.com>
Date: Mon, 27 May 2013 16:38:25 +1000
Subject: [PATCH] xfs: kill suid/sgid through the truncate path.

commit 2962f5a5dcc56f69cbf62121a7be67cc15d6940b upstream.

XFS has failed to kill suid/sgid bits correctly when truncating
files of non-zero size since commit c4ed4243 ("xfs: split
xfs_setattr") introduced in the 3.1 kernel. Fix it.

Fix it.

Signed-off-by: Dave Chinner <dchinner at redhat.com>
Reviewed-by: Brian Foster <bfoster at redhat.com>
Signed-off-by: Ben Myers <bpm at sgi.com>

(cherry picked from commit 56c19e89b38618390addfc743d822f99519055c6)
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/xfs/xfs_iops.c | 47 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 32 insertions(+), 15 deletions(-)

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 1a25fd8..1ad330c 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -454,6 +454,28 @@ xfs_vn_getattr(
 	return 0;
 }

+static void
+xfs_setattr_mode(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	struct iattr		*iattr)
+{
+	struct inode	*inode = VFS_I(ip);
+	umode_t		mode = iattr->ia_mode;
+
+	ASSERT(tp);
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+		mode &= ~S_ISGID;
+
+	ip->i_d.di_mode &= S_IFMT;
+	ip->i_d.di_mode |= mode & ~S_IFMT;
+
+	inode->i_mode &= S_IFMT;
+	inode->i_mode |= mode & ~S_IFMT;
+}
+
 int
 xfs_setattr_nonsize(
 	struct xfs_inode	*ip,
@@ -605,18 +627,8 @@ xfs_setattr_nonsize(
 	/*
 	 * Change file access modes.
 	 */
-	if (mask & ATTR_MODE) {
-		umode_t mode = iattr->ia_mode;
-
-		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
-			mode &= ~S_ISGID;
-
-		ip->i_d.di_mode &= S_IFMT;
-		ip->i_d.di_mode |= mode & ~S_IFMT;
-
-		inode->i_mode &= S_IFMT;
-		inode->i_mode |= mode & ~S_IFMT;
-	}
+	if (mask & ATTR_MODE)
+		xfs_setattr_mode(tp, ip, iattr);

 	/*
 	 * Change file access or modified times.
@@ -713,9 +725,8 @@ xfs_setattr_size(
 		return XFS_ERROR(error);

 	ASSERT(S_ISREG(ip->i_d.di_mode));
-	ASSERT((mask & (ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET|
-			ATTR_MTIME_SET|ATTR_KILL_SUID|ATTR_KILL_SGID|
-			ATTR_KILL_PRIV|ATTR_TIMES_SET)) == 0);
+	ASSERT((mask & (ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_ATIME_SET|
+			ATTR_MTIME_SET|ATTR_KILL_PRIV|ATTR_TIMES_SET)) == 0);

 	if (!(flags & XFS_ATTR_NOLOCK)) {
 		lock_flags |= XFS_IOLOCK_EXCL;
@@ -856,6 +867,12 @@ xfs_setattr_size(
 		xfs_iflags_set(ip, XFS_ITRUNCATED);
 	}

+	/*
+	 * Change file access modes.
+	 */
+	if (mask & ATTR_MODE)
+		xfs_setattr_mode(tp, ip, iattr);
+
 	if (mask & ATTR_CTIME) {
 		inode->i_ctime = iattr->ia_ctime;
 		ip->i_d.di_ctime.t_sec = iattr->ia_ctime.tv_sec;
--
1.8.1.2