From: Cong Wang <xiyou.wangcong@gmail.com>
To: Davide Caratti <dcaratti@redhat.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>,
Jiri Pirko <jiri@resnulli.us>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, wenxu <wenxu@ucloud.cn>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Subject: Re: [PATCH net 2/2] net/sched: sch_frag: fix stack OOB read while fragmenting IPv4 packets
Date: Tue, 20 Apr 2021 12:27:19 -0700 [thread overview]
Message-ID: <CAM_iQpVz9H3ebCKaXhTf2NzTzU_+pEUQhxNP+OCVX1KY0gaxzg@mail.gmail.com> (raw)
In-Reply-To: <80dbe764b5ae660bba3cf6edcb045a74b0f85853.1618844973.git.dcaratti@redhat.com>
On Mon, Apr 19, 2021 at 8:24 AM Davide Caratti <dcaratti@redhat.com> wrote:
>
> when 'act_mirred' tries to fragment IPv4 packets that had been previously
> re-assembled using 'act_ct', splats like the following can be observed on
> kernels built with KASAN:
[...]
> for IPv4 packets, sch_fragment() uses a temporary struct dst_entry. Then,
> in the following call graph:
>
> ip_do_fragment()
> ip_skb_dst_mtu()
> ip_dst_mtu_maybe_forward()
> ip_mtu_locked()
>
> the pointer to struct dst_entry is used as pointer to struct rtable: this
> turns the access to struct members like rt_mtu_locked into an OOB read in
> the stack. Fix this changing the temporary variable used for IPv4 packets
> in sch_fragment(), similarly to what is done for IPv6 few lines below.
>
> Fixes: c129412f74e9 ("net/sched: sch_frag: add generic packet fragment support.")
> Cc: <stable@vger.kernel.org> # 5.11
> Reported-by: Shuang Li <shuali@redhat.com>
> Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Thanks.
next prev parent reply other threads:[~2021-04-20 19:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-19 15:22 [PATCH net 0/2] fix stack OOB read while fragmenting IPv4 packets Davide Caratti
2021-04-19 15:23 ` [PATCH net 1/2] openvswitch: " Davide Caratti
2021-04-21 9:27 ` Eelco Chaudron
2021-04-21 15:05 ` Davide Caratti
2021-04-22 9:17 ` Eelco Chaudron
2021-04-19 15:23 ` [PATCH net 2/2] net/sched: sch_frag: " Davide Caratti
2021-04-19 17:38 ` Marcelo Ricardo Leitner
2021-04-19 18:46 ` Cong Wang
2021-04-20 8:59 ` Davide Caratti
2021-04-20 19:25 ` Cong Wang
2021-04-20 19:27 ` Cong Wang [this message]
2021-04-23 12:11 ` [PATCH net 0/2] " Davide Caratti
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