Fwd: [PATCH v2] cifs: fix use-after-free on the link name

From: Steve French
Date: Sat Nov 05 2022 - 00:39:33 EST


tentatively merged into cifs-2.6.git for-next pending additional testing

On Fri, Nov 4, 2022 at 12:57 PM Paulo Alcantara via samba-technical
<samba-technical@xxxxxxxxxxxxxxx> wrote:
>
> ChenXiaoSong <chenxiaosong2@xxxxxxxxxx> writes:
>
> > When opened a symlink, link name is from 'inode->i_link', but it may be
> > reset to a new value when revalidate the dentry. If some processes get the
> > link name on the race scenario, then UAF will happen on link name.
> >
> > Fix this by implementing 'get_link' interface to duplicate the link name.
> >
> > Fixes: 76894f3e2f71 ("cifs: improve symlink handling for smb2+")
> > Signed-off-by: ChenXiaoSong <chenxiaosong2@xxxxxxxxxx>
> > ---
> > fs/cifs/cifsfs.c | 26 +++++++++++++++++++++++++-
> > fs/cifs/inode.c | 5 -----
> > 2 files changed, 25 insertions(+), 6 deletions(-)
>
> Reviewed-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
>


--
Thanks,

Steve


--
Thanks,

Steve