net: sched: protect against stack overflow in TC act_mirred
mainline inclusion from mainline-v5.3-rc1 commit e2ca070f 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=v6.3-rc2&id=e2ca070f89ecd983bd98e05d936a678a4151f2fd -------------------------------- TC hooks allow the application of filters and actions to packets at both ingress and egress of the network stack. It is possible, with poor configuration, that this can produce loops whereby an ingress hook calls a mirred egress action that has an egress hook that redirects back to the first ingress etc. The TC core classifier protects against loops when doing reclassifies but there is no protection against a packet looping between multiple hooks and recursively calling act_mirred. This can lead to stack overflow panics. Add a per CPU counter to act_mirred that is incremented for each recursive call of the action function when processing a packet. If a limit is passed then the packet is dropped and CPU counter reset. Note that this patch does not protect against loops in TC datapaths. Its aim is to prevent stack overflow kernel panics that can be a consequence of such loops. Signed-off-by:John Hurley <john.hurley@netronome.com> Reviewed-by:
Simon Horman <simon.horman@netronome.com> Signed-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
Ziyang Xuan <william.xuanziyang@huawei.com> Reviewed-by:
Liu Jian <liujian56@huawei.com> Reviewed-by:
Wang Weiyang <wangweiyang2@huawei.com> Signed-off-by:
Yongqiang Liu <liuyongqiang13@huawei.com>
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