tree 65a1d746f84cb8aa9be2a69c59eb627859b9fa0d
parent 440b3c6c160f7d0a985f24ad1f4c24e00ee2d936
author Miklos Szeredi <mszeredi@suse.cz> 1265800553 +0100
committer Al Viro <viro@zeniv.linux.org.uk> 1267643280 -0500

vfs: add NOFOLLOW flag to umount(2)

Add a new UMOUNT_NOFOLLOW flag to umount(2).  This is needed to prevent
symlink attacks in unprivileged unmounts (fuse, samba, ncpfs).

Additionally, return -EINVAL if an unknown flag is used (and specify
an explicitly unused flag: UMOUNT_UNUSED).  This makes it possible for
the caller to determine if a flag is supported or not.

CC: Eugene Teo <eugene@redhat.com>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>