| Message ID | 87y3moiqc9.fsf@xmission.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
diff --git a/fs/namei.c b/fs/namei.c index f0c7a7b9b6ca..f47118ed36e7 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1142,9 +1142,6 @@ static int follow_automount(struct path *path, struct nameidata *nd, return -ENOENT; } - if (path->dentry->d_sb->s_user_ns != &init_user_ns) - return -EACCES; - nd->total_link_count++; if (nd->total_link_count >= 40) return -ELOOP;
When vfs_submount was added the test to limit automounts from filesystems that with s_user_ns != &init_user_ns accidentially left in follow_automount. The test was never about any security concerns and was always about how do we implement this for filesystems whose s_user_ns != &init_user_ns. At the moment this check makes no difference as there are no filesystems that both set FS_USERNS_MOUNT and implement d_automount. Remove this check now while I am thinking about it so there will not be odd booby traps for someone who does want to make this combination work. vfs_submount still needs improvements to allow this combination to work, and vfs_submount contains a check that presents a warning. The autofs4 filesystem could be modified to set FS_USERNS_MOUNT and it would need not work on this code path, as userspace performs the mounts. Fixes: 93faccbbfa95 ("fs: Better permission checking for submounts") Fixes: aeaa4a79ff6a ("fs: Call d_automount with the filesystems creds") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> --- fs/namei.c | 3 --- 1 file changed, 3 deletions(-)