From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Jamal Hadi Salim <jhs@mojatatu.com>,
Stephen Hemminger <stephen@networkplumber.org>,
"David S. Miller" <davem@davemloft.net>
Subject: [PATCH 5.15 03/14] net_sched: cls_route: disallow handle of 0
Date: Fri, 19 Aug 2022 17:40:19 +0200 [thread overview]
Message-ID: <20220819153711.787764500@linuxfoundation.org> (raw)
In-Reply-To: <20220819153711.658766010@linuxfoundation.org>
From: Jamal Hadi Salim <jhs@mojatatu.com>
commit 02799571714dc5dd6948824b9d080b44a295f695 upstream.
Follows up on:
https://lore.kernel.org/all/20220809170518.164662-1-cascardo@canonical.com/
handle of 0 implies from/to of universe realm which is not very
sensible.
Lets see what this patch will do:
$sudo tc qdisc add dev $DEV root handle 1:0 prio
//lets manufacture a way to insert handle of 0
$sudo tc filter add dev $DEV parent 1:0 protocol ip prio 100 \
route to 0 from 0 classid 1:10 action ok
//gets rejected...
Error: handle of 0 is not valid.
We have an error talking to the kernel, -1
//lets create a legit entry..
sudo tc filter add dev $DEV parent 1:0 protocol ip prio 100 route from 10 \
classid 1:10 action ok
//what did the kernel insert?
$sudo tc filter ls dev $DEV parent 1:0
filter protocol ip pref 100 route chain 0
filter protocol ip pref 100 route chain 0 fh 0x000a8000 flowid 1:10 from 10
action order 1: gact action pass
random type none pass val 0
index 1 ref 1 bind 1
//Lets try to replace that legit entry with a handle of 0
$ sudo tc filter replace dev $DEV parent 1:0 protocol ip prio 100 \
handle 0x000a8000 route to 0 from 0 classid 1:10 action drop
Error: Replacing with handle of 0 is invalid.
We have an error talking to the kernel, -1
And last, lets run Cascardo's POC:
$ ./poc
0
0
-22
-22
-22
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/sched/cls_route.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -424,6 +424,11 @@ static int route4_set_parms(struct net *
return -EINVAL;
}
+ if (!nhandle) {
+ NL_SET_ERR_MSG(extack, "Replacing with handle of 0 is invalid");
+ return -EINVAL;
+ }
+
h1 = to_hash(nhandle);
b = rtnl_dereference(head->table[h1]);
if (!b) {
@@ -477,6 +482,11 @@ static int route4_change(struct net *net
int err;
bool new = true;
+ if (!handle) {
+ NL_SET_ERR_MSG(extack, "Creating with handle of 0 is invalid");
+ return -EINVAL;
+ }
+
if (opt == NULL)
return handle ? -EINVAL : 0;
next prev parent reply other threads:[~2022-08-19 15:42 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-19 15:40 [PATCH 5.15 00/14] 5.15.62-rc1 review Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 01/14] io_uring: use original request task for inflight tracking Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 02/14] tee: add overflow check in register_shm_helper() Greg Kroah-Hartman
2022-08-19 15:40 ` Greg Kroah-Hartman [this message]
2022-08-19 15:40 ` [PATCH 5.15 04/14] ksmbd: prevent out of bound read for SMB2_WRITE Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 05/14] ksmbd: fix heap-based overflow in set_ntacl_dacl() Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 06/14] Revert "x86/ftrace: Use alternative RET encoding" Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 07/14] x86/ibt,ftrace: Make function-graph play nice Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 08/14] x86/ftrace: Use alternative RET encoding Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 09/14] btrfs: only write the sectors in the vertical stripe which has data stripes Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 10/14] btrfs: raid56: dont trust any cached sector in __raid56_parity_recover() Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 11/14] kexec_file: drop weak attribute from functions Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 12/14] kexec: clean up arch_kexec_kernel_verify_sig Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 13/14] kexec, KEYS: make the code in bzImage64_verify_sig generic Greg Kroah-Hartman
2022-08-19 15:40 ` [PATCH 5.15 14/14] arm64: kexec_file: use more system keyrings to verify kernel image signature Greg Kroah-Hartman
2022-08-20 0:42 ` [PATCH 5.15 00/14] 5.15.62-rc1 review Shuah Khan
2022-08-20 8:27 ` Naresh Kamboju
2022-08-20 18:17 ` Greg Kroah-Hartman
2022-08-20 10:05 ` Bagas Sanjaya
2022-08-20 10:42 ` Sudip Mukherjee (Codethink)
2022-08-20 22:23 ` Ron Economos
2022-08-21 0:56 ` Guenter Roeck
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