* Patch "netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets" has been added to the 4.14-stable tree
@ 2018-03-13 11:14 gregkh
2018-03-13 11:29 ` Florian Westphal
0 siblings, 1 reply; 4+ messages in thread
From: gregkh @ 2018-03-13 11:14 UTC (permalink / raw)
To: fw, gregkh, pablo, syzbot+845a53d13171abf8bf29; +Cc: stable, stable-commits
This is a note to let you know that I've just added the patch titled
netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
netfilter-ebtables-config_compat-don-t-trust-userland-offsets.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From b71812168571fa55e44cdd0254471331b9c4c4c6 Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Mon, 19 Feb 2018 01:24:15 +0100
Subject: netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets
From: Florian Westphal <fw@strlen.de>
commit b71812168571fa55e44cdd0254471331b9c4c4c6 upstream.
We need to make sure the offsets are not out of range of the
total size.
Also check that they are in ascending order.
The WARN_ON triggered by syzkaller (it sets panic_on_warn) is
changed to also bail out, no point in continuing parsing.
Briefly tested with simple ruleset of
-A INPUT --limit 1/s' --log
plus jump to custom chains using 32bit ebtables binary.
Reported-by: <syzbot+845a53d13171abf8bf29@syzkaller.appspotmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bridge/netfilter/ebtables.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -2053,7 +2053,9 @@ static int ebt_size_mwt(struct compat_eb
if (match_kern)
match_kern->match_size = ret;
- WARN_ON(type == EBT_COMPAT_TARGET && size_left);
+ if (WARN_ON(type == EBT_COMPAT_TARGET && size_left))
+ return -EINVAL;
+
match32 = (struct compat_ebt_entry_mwt *) buf;
}
@@ -2109,6 +2111,15 @@ static int size_entry_mwt(struct ebt_ent
*
* offsets are relative to beginning of struct ebt_entry (i.e., 0).
*/
+ for (i = 0; i < 4 ; ++i) {
+ if (offsets[i] >= *total)
+ return -EINVAL;
+ if (i == 0)
+ continue;
+ if (offsets[i-1] > offsets[i])
+ return -EINVAL;
+ }
+
for (i = 0, j = 1 ; j < 4 ; j++, i++) {
struct compat_ebt_entry_mwt *match32;
unsigned int size;
Patches currently in stable-queue which might be from fw@strlen.de are
queue-4.14/netfilter-add-back-stackpointer-size-checks.patch
queue-4.14/netfilter-ipv6-fix-use-after-free-write-in-nf_nat_ipv6_manip_pkt.patch
queue-4.14/netfilter-ebtables-config_compat-don-t-trust-userland-offsets.patch
queue-4.14/netfilter-bridge-ebt_among-add-missing-match-size-checks.patch
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Patch "netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets" has been added to the 4.14-stable tree
2018-03-13 11:14 Patch "netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets" has been added to the 4.14-stable tree gregkh
@ 2018-03-13 11:29 ` Florian Westphal
2018-03-13 11:31 ` Greg KH
0 siblings, 1 reply; 4+ messages in thread
From: Florian Westphal @ 2018-03-13 11:29 UTC (permalink / raw)
To: gregkh; +Cc: fw, pablo, stable
gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> wrote:
> netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets
>
> to the 4.14-stable tree which can be found at:
> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
This needs
commit 932909d9b28d27e807ff8eecb68c7748f6701628
("netfilter: ebtables: fix erroneous reject of last rule")
as a followup fix, else it becomes impossible to add rules
to the last builtin base chain.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Patch "netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets" has been added to the 4.14-stable tree
2018-03-13 11:29 ` Florian Westphal
@ 2018-03-13 11:31 ` Greg KH
2018-03-13 11:35 ` Florian Westphal
0 siblings, 1 reply; 4+ messages in thread
From: Greg KH @ 2018-03-13 11:31 UTC (permalink / raw)
To: Florian Westphal; +Cc: pablo, stable
On Tue, Mar 13, 2018 at 12:29:30PM +0100, Florian Westphal wrote:
> gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> wrote:
> > netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets
> >
> > to the 4.14-stable tree which can be found at:
> > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>
> This needs
>
> commit 932909d9b28d27e807ff8eecb68c7748f6701628
> ("netfilter: ebtables: fix erroneous reject of last rule")
>
> as a followup fix, else it becomes impossible to add rules
> to the last builtin base chain.
That's not in Linus's tree yet :(
Is it in Dave's tree to be sent to Linus soon?
thanks,
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Patch "netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets" has been added to the 4.14-stable tree
2018-03-13 11:31 ` Greg KH
@ 2018-03-13 11:35 ` Florian Westphal
0 siblings, 0 replies; 4+ messages in thread
From: Florian Westphal @ 2018-03-13 11:35 UTC (permalink / raw)
To: Greg KH; +Cc: Florian Westphal, pablo, stable
Greg KH <gregkh@linuxfoundation.org> wrote:
> On Tue, Mar 13, 2018 at 12:29:30PM +0100, Florian Westphal wrote:
> > gregkh@linuxfoundation.org <gregkh@linuxfoundation.org> wrote:
> > > netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets
> > >
> > > to the 4.14-stable tree which can be found at:
> > > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> >
> > This needs
> >
> > commit 932909d9b28d27e807ff8eecb68c7748f6701628
> > ("netfilter: ebtables: fix erroneous reject of last rule")
> >
> > as a followup fix, else it becomes impossible to add rules
> > to the last builtin base chain.
>
> That's not in Linus's tree yet :(
>
> Is it in Dave's tree to be sent to Linus soon?
It got placed into net.git yesterday...
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-03-13 11:14 Patch "netfilter: ebtables: CONFIG_COMPAT: don't trust userland offsets" has been added to the 4.14-stable tree gregkh
2018-03-13 11:29 ` Florian Westphal
2018-03-13 11:31 ` Greg KH
2018-03-13 11:35 ` Florian Westphal
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