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 <[email protected]>
CC: Michael Kerrisk <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>
Signed-off-by: Al Viro <[email protected]>
2 files changed
