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@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
(cherry picked from commit 56c19e89b38618390addfc743d822f99519055c6)
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 23ce927..bd2fb43 100644 (file)
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -507,6 +507,28 @@ 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,
@@ -658,18 +680,8 @@ 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.
@@ -768,9 +780,8 @@ 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);
 
        lock_flags = XFS_ILOCK_EXCL;
        if (!(flags & XFS_ATTR_NOLOCK))
@@ -902,6 +913,12 @@ 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;