]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
Fix permission checking for the new utimensat() system call
authorLinus Torvalds <torvalds@woody.linux-foundation.org>
Sun, 8 Jul 2007 19:02:55 +0000 (12:02 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Sun, 8 Jul 2007 19:02:55 +0000 (12:02 -0700)
Commit 1c710c896eb461895d3c399e15bb5f20b39c9073 added the utimensat()
system call, but didn't handle the case of checking for the writability
of the target right, when the target was a file descriptor, not a
filename.

We cannot use vfs_permission(MAY_WRITE) for that case, and need to
simply check whether the file descriptor is writable.  The oops from
using the wrong function was noticed and narrowed down by Markus
Trippelsdorf.

Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/utimes.c

index 480f7c8c29da13ee10941f5cf5e560faffbde0a6..b3c88952465fa28cce7e0bb213fceaf59873fdf9 100644 (file)
@@ -106,9 +106,16 @@ long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags
                 if (IS_IMMUTABLE(inode))
                         goto dput_and_out;
 
-               if (current->fsuid != inode->i_uid &&
-                   (error = vfs_permission(&nd, MAY_WRITE)) != 0)
-                       goto dput_and_out;
+               if (current->fsuid != inode->i_uid) {
+                       if (f) {
+                               if (!(f->f_mode & FMODE_WRITE))
+                                       goto dput_and_out;
+                       } else {
+                               error = vfs_permission(&nd, MAY_WRITE);
+                               if (error)
+                                       goto dput_and_out;
+                       }
+               }
        }
        mutex_lock(&inode->i_mutex);
        error = notify_change(dentry, &newattrs);