mainline inclusion
from mainline-v6.3-rc1
commit ca22da2f
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I64END
CVE: CVE-2022-4269

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.2-rc7&id=ca22da2fbd693b54dc8e3b7b54ccc9f7e9ba3640

--------------------------------

William reports kernel soft-lockups on some OVS topologies when TC mirred
egress->ingress action is hit by local TCP traffic [1].
The same can also be reproduced with SCTP (thanks Xin for verifying), when
client and server reach themselves through mirred egress to ingress, and
one of the two peers sends a "heartbeat" packet (from within a timer).

Enqueueing to backlog proved to fix this soft lockup; however, as Cong
noticed [2], we should preserve - when possible - the current mirred
behavior that counts as "overlimits" any eventual packet drop subsequent to
the mirred forwarding action [3]. A compromise solution might use the
backlog only when tcf_mirred_act() has a nest level greater than one:
change tcf_mirred_forward() accordingly.

Also, add a kselftest that can reproduce the lockup and verifies TC mirred
ability to account for further packet drops after TC mirred egress->ingress
(when the nest level is 1).

 [1] https://lore.kernel.org/netdev/33dc43f587ec1388ba456b4915c75f02a8aae226.1663945716.git.dcaratti@redhat.com/
 [2] https://lore.kernel.org/netdev/Y0w%2FWWY60gqrtGLp@pop-os.localdomain/
 [3] such behavior is not guaranteed: for example, if RPS or skb RX
     timestamping is enabled on the mirred target device, the kernel
     can defer receiving the skb and return NET_RX_SUCCESS inside
     tcf_mirred_forward().
Reported-by: NWilliam Zhao <wizhao@redhat.com>
CC: Xin Long <lucien.xin@gmail.com>
Signed-off-by: NDavide Caratti <dcaratti@redhat.com>
Reviewed-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Conflicts:
	net/sched/act_mirred.c
	tools/testing/selftests/net/forwarding/tc_actions.sh
Signed-off-by: NZiyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: NLiu Jian <liujian56@huawei.com>
Reviewed-by: NWang Weiyang <wangweiyang2@huawei.com>
Signed-off-by: NJialin Zhang <zhangjialin11@huawei.com>