* FAILED: patch "[PATCH] ovl: check whiteout in ovl_create_over_whiteout()" failed to apply to 4.14-stable tree
@ 2018-11-15 0:08 gregkh
2018-11-15 9:40 ` Miklos Szeredi
0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2018-11-15 0:08 UTC (permalink / raw)
To: mszeredi, stable, xiakaixu1987; +Cc: stable
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 5e1275808630ea3b2c97c776f40e475017535f72 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@redhat.com>
Date: Wed, 31 Oct 2018 12:15:23 +0100
Subject: [PATCH] ovl: check whiteout in ovl_create_over_whiteout()
Kaixuxia repors that it's possible to crash overlayfs by removing the
whiteout on the upper layer before creating a directory over it. This is a
reproducer:
mkdir lower upper work merge
touch lower/file
mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merge
rm merge/file
ls -al merge/file
rm upper/file
ls -al merge/
mkdir merge/file
Before commencing with a vfs_rename(..., RENAME_EXCHANGE) verify that the
lookup of "upper" is positive and is a whiteout, and return ESTALE
otherwise.
Reported by: kaixuxia <xiakaixu1987@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: e9be9d5e76e3 ("overlay filesystem")
Cc: <stable@vger.kernel.org> # v3.18
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index ce1857fb5434..c6289147c787 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -462,6 +462,10 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
if (IS_ERR(upper))
goto out_unlock;
+ err = -ESTALE;
+ if (d_is_negative(upper) || !IS_WHITEOUT(d_inode(upper)))
+ goto out_dput;
+
newdentry = ovl_create_temp(workdir, cattr);
err = PTR_ERR(newdentry);
if (IS_ERR(newdentry))
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: FAILED: patch "[PATCH] ovl: check whiteout in ovl_create_over_whiteout()" failed to apply to 4.14-stable tree
2018-11-15 0:08 FAILED: patch "[PATCH] ovl: check whiteout in ovl_create_over_whiteout()" failed to apply to 4.14-stable tree gregkh
@ 2018-11-15 9:40 ` Miklos Szeredi
2018-11-19 15:07 ` Greg Kroah-Hartman
0 siblings, 1 reply; 3+ messages in thread
From: Miklos Szeredi @ 2018-11-15 9:40 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: stable, xiakaixu1987
[-- Attachment #1: Type: text/plain, Size: 391 bytes --]
On Thu, Nov 15, 2018 at 1:08 AM <gregkh@linuxfoundation.org> wrote:
>
>
> The patch below does not apply to the 4.14-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.
Attaching backport. Should also apply cleanly to v4.10..v4.17.
Thanks,
Miklos
[-- Attachment #2: 4.14.y-ovl-check-whiteout-in-ovl_create_over_whiteout.patch --]
[-- Type: application/x-patch, Size: 1434 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: FAILED: patch "[PATCH] ovl: check whiteout in ovl_create_over_whiteout()" failed to apply to 4.14-stable tree
2018-11-15 9:40 ` Miklos Szeredi
@ 2018-11-19 15:07 ` Greg Kroah-Hartman
0 siblings, 0 replies; 3+ messages in thread
From: Greg Kroah-Hartman @ 2018-11-19 15:07 UTC (permalink / raw)
To: Miklos Szeredi; +Cc: stable, xiakaixu1987
On Thu, Nov 15, 2018 at 10:40:09AM +0100, Miklos Szeredi wrote:
> On Thu, Nov 15, 2018 at 1:08 AM <gregkh@linuxfoundation.org> wrote:
> >
> >
> > The patch below does not apply to the 4.14-stable tree.
> > If someone wants it applied there, or to any other stable or longterm
> > tree, then please email the backport, including the original git commit
> > id to <stable@vger.kernel.org>.
>
> Attaching backport. Should also apply cleanly to v4.10..v4.17.
Now applied, thanks.
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-11-20 1:31 UTC | newest]
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2018-11-15 0:08 FAILED: patch "[PATCH] ovl: check whiteout in ovl_create_over_whiteout()" failed to apply to 4.14-stable tree gregkh
2018-11-15 9:40 ` Miklos Szeredi
2018-11-19 15:07 ` Greg Kroah-Hartman
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