Messages in this thread | | | From | Amir Goldstein <> | Date | Tue, 28 Aug 2018 21:42:09 +0300 | Subject | Re: [PATCH v5 2/3] overlayfs: check CAP_MKNOD before issuing vfs_whiteout |
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On Tue, Aug 28, 2018 at 8:43 PM Amir Goldstein <amir73il@gmail.com> wrote: > > On Tue, Aug 28, 2018 at 7:53 PM Mark Salyzyn <salyzyn@android.com> wrote: > > > > Assumption never checked, should fail if the mounter creds are not > > sufficient. > > > > Signed-off-by: Mark Salyzyn <salyzyn@android.com> > > Cc: Miklos Szeredi <miklos@szeredi.hu> > > Cc: Jonathan Corbet <corbet@lwn.net> > > Cc: Vivek Goyal <vgoyal@redhat.com> > > Cc: Eric W. Biederman <ebiederm@xmission.com> > > Cc: Amir Goldstein <amir73il@gmail.com> > > Cc: Randy Dunlap <rdunlap@infradead.org> > > Cc: Stephen Smalley <sds@tycho.nsa.gov> > > Cc: linux-unionfs@vger.kernel.org > > Cc: linux-doc@vger.kernel.org > > Cc: linux-kernel@vger.kernel.org > > > > v5 > > - dependency of "overlayfs: override_creds=off option bypass creator_cred" > > --- > > fs/overlayfs/overlayfs.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h > > index 7538b9b56237..bf3a80157d42 100644 > > --- a/fs/overlayfs/overlayfs.h > > +++ b/fs/overlayfs/overlayfs.h > > @@ -176,7 +176,7 @@ static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry, > > > > static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry) > > { > > - int err = vfs_whiteout(dir, dentry); > > + int err = capable(CAP_MKNOD) ? vfs_whiteout(dir, dentry) : -EPERM; > > Should that be ns_capable()? Should the test go into vfs_whiteout()? > I feel there is no convention at all. >
Nevermind, I don't think creating a whiteout poses any risk, so don't think we need to worry about CAP_MKNOD.
Thanks, Amir.
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