[ 3.8.y.z extended stable ] Patch "xfs: kill suid/sgid through the truncate path." 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: kill suid/sgid through the truncate path.

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 3.8.13.2.

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 fdb8095b7f0283d0effbdafb23932a2ff912a221 Mon Sep 17 00:00:00 2001
From: Dave Chinner <dchinner at redhat.com>
Date: Mon, 27 May 2013 16:38:25 +1000
Subject: 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: Kamal Mostafa <kamal 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 d82efaa..ca9ecaa 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -455,6 +455,28 @@ 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,
@@ -606,18 +628,8 @@ 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.
@@ -714,9 +726,8 @@ 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;
@@ -860,6 +871,12 @@ xfs_setattr_size(
 		xfs_inode_clear_eofblocks_tag(ip);
 	}

+	/*
+	 * 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