This is a note to let you know that I've just added the patch titled
net_sched: cls_route: remove from list when handle is 0
to the 5.18-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-cls_route-remove-from-list-when-handle-is-0.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9ad36309e2719a884f946678e0296be10f0bb4c1 Mon Sep 17 00:00:00 2001
From: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
Date: Tue, 9 Aug 2022 14:05:18 -0300
Subject: net_sched: cls_route: remove from list when handle is 0
From: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
commit 9ad36309e2719a884f946678e0296be10f0bb4c1 upstream.
When a route filter is replaced and the old filter has a 0 handle, the old
one won't be removed from the hashtable, while it will still be freed.
The test was there since before commit 1109c00547fc ("net: sched: RCU
cls_route"), when a new filter was not allocated when there was an old one.
The old filter was reused and the reinserting would only be necessary if an
old filter was replaced. That was still wrong for the same case where the
old handle was 0.
Remove the old filter from the list independently from its handle value.
This fixes CVE-2022-2588, also reported as ZDI-CAN-17440.
Reported-by: Zhenpeng Lin <zplin@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
Reviewed-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Acked-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220809170518.164662-1-cascardo@xxxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/cls_route.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -526,7 +526,7 @@ static int route4_change(struct net *net
rcu_assign_pointer(f->next, f1);
rcu_assign_pointer(*fp, f);
- if (fold && fold->handle && f->handle != fold->handle) {
+ if (fold) {
th = to_hash(fold->handle);
h = from_hash(fold->handle >> 16);
b = rtnl_dereference(head->table[th]);
Patches currently in stable-queue which might be from cascardo@xxxxxxxxxxxxx are
queue-5.18/netfilter-nf_tables-do-not-allow-chain_id-to-refer-to-another-table.patch
queue-5.18/netfilter-nf_tables-do-not-allow-set_id-to-refer-to-another-table.patch
queue-5.18/posix-cpu-timers-cleanup-cpu-timers-before-freeing-them-during-exec.patch
queue-5.18/net_sched-cls_route-remove-from-list-when-handle-is-0.patch
queue-5.18/netfilter-nf_tables-do-not-allow-rule_id-to-refer-to-another-chain.patch
