This is a note to let you know that I've just added the patch titled
net/sched: act_mpls: ensure LSE is pullable before reading it
to the 5.9-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:
net-sched-act_mpls-ensure-lse-is-pullable-before-reading-it.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Sun Dec 6 10:19:03 AM CET 2020
From: Davide Caratti <dcaratti@xxxxxxxxxx>
Date: Thu, 3 Dec 2020 10:37:52 +0100
Subject: net/sched: act_mpls: ensure LSE is pullable before reading it
From: Davide Caratti <dcaratti@xxxxxxxxxx>
[ Upstream commit 9608fa653059c3f72faab0c148ac8773c46e7314 ]
when 'act_mpls' is used to mangle the LSE, the current value is read from
the packet dereferencing 4 bytes at mpls_hdr(): ensure that the label is
contained in the skb "linear" area.
Found by code inspection.
v2:
- use MPLS_HLEN instead of sizeof(new_lse), thanks to Jakub Kicinski
Fixes: 2a2ea50870ba ("net: sched: add mpls manipulation actions to TC")
Signed-off-by: Davide Caratti <dcaratti@xxxxxxxxxx>
Acked-by: Guillaume Nault <gnault@xxxxxxxxxx>
Link: https://lore.kernel.org/r/3243506cba43d14858f3bd21ee0994160e44d64a.1606987058.git.dcaratti@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/act_mpls.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/sched/act_mpls.c
+++ b/net/sched/act_mpls.c
@@ -88,6 +88,9 @@ static int tcf_mpls_act(struct sk_buff *
goto drop;
break;
case TCA_MPLS_ACT_MODIFY:
+ if (!pskb_may_pull(skb,
+ skb_network_offset(skb) + MPLS_HLEN))
+ goto drop;
new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
if (skb_mpls_update_lse(skb, new_lse))
goto drop;
Patches currently in stable-queue which might be from dcaratti@xxxxxxxxxx are
queue-5.9/net-openvswitch-ensure-lse-is-pullable-before-reading-it.patch
queue-5.9/net-skbuff-ensure-lse-is-pullable-before-decrementing-the-mpls-ttl.patch
queue-5.9/mptcp-fix-null-ptr-dereference-on-bad-mpj.patch
queue-5.9/net-sched-act_mpls-ensure-lse-is-pullable-before-reading-it.patch
