From: Daniel Borkmann <daniel@iogearbox.net>
To: Nikolay Aleksandrov <razor@blackwall.org>, netdev@vger.kernel.org
Cc: kuba@kernel.org, davem@davemloft.net, stable@vger.kernel.org,
Jason Wang <jasowang@redhat.com>,
Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
"Michael S. Tsirkin" <mst@redhat.com>,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH net v3] virtio_net: fix wrong buf address calculation when using xdp
Date: Mon, 25 Apr 2022 15:10:33 +0200 [thread overview]
Message-ID: <00a5d84e-298e-3ca4-c6da-826e6fe586de@iogearbox.net> (raw)
In-Reply-To: <20220425103703.3067292-1-razor@blackwall.org>
On 4/25/22 12:37 PM, Nikolay Aleksandrov wrote:
> We received a report[1] of kernel crashes when Cilium is used in XDP
> mode with virtio_net after updating to newer kernels. After
> investigating the reason it turned out that when using mergeable bufs
> with an XDP program which adjusts xdp.data or xdp.data_meta page_to_buf()
> calculates the build_skb address wrong because the offset can become less
> than the headroom so it gets the address of the previous page (-X bytes
> depending on how lower offset is):
> page_to_skb: page addr ffff9eb2923e2000 buf ffff9eb2923e1ffc offset 252 headroom 256
[...]
> CC: stable@vger.kernel.org
> CC: Jason Wang <jasowang@redhat.com>
> CC: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> CC: Daniel Borkmann <daniel@iogearbox.net>
> CC: "Michael S. Tsirkin" <mst@redhat.com>
> CC: virtualization@lists.linux-foundation.org
> Fixes: 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr")
> Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Thanks everyone!
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
WARNING: multiple messages have this Message-ID (diff)
From: Daniel Borkmann <daniel@iogearbox.net>
To: Nikolay Aleksandrov <razor@blackwall.org>, netdev@vger.kernel.org
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
stable@vger.kernel.org,
virtualization@lists.linux-foundation.org, kuba@kernel.org,
davem@davemloft.net
Subject: Re: [PATCH net v3] virtio_net: fix wrong buf address calculation when using xdp
Date: Mon, 25 Apr 2022 15:10:33 +0200 [thread overview]
Message-ID: <00a5d84e-298e-3ca4-c6da-826e6fe586de@iogearbox.net> (raw)
In-Reply-To: <20220425103703.3067292-1-razor@blackwall.org>
On 4/25/22 12:37 PM, Nikolay Aleksandrov wrote:
> We received a report[1] of kernel crashes when Cilium is used in XDP
> mode with virtio_net after updating to newer kernels. After
> investigating the reason it turned out that when using mergeable bufs
> with an XDP program which adjusts xdp.data or xdp.data_meta page_to_buf()
> calculates the build_skb address wrong because the offset can become less
> than the headroom so it gets the address of the previous page (-X bytes
> depending on how lower offset is):
> page_to_skb: page addr ffff9eb2923e2000 buf ffff9eb2923e1ffc offset 252 headroom 256
[...]
> CC: stable@vger.kernel.org
> CC: Jason Wang <jasowang@redhat.com>
> CC: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
> CC: Daniel Borkmann <daniel@iogearbox.net>
> CC: "Michael S. Tsirkin" <mst@redhat.com>
> CC: virtualization@lists.linux-foundation.org
> Fixes: 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr")
> Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Thanks everyone!
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
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Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2022-04-25 13:10 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-25 10:37 [PATCH net v3] virtio_net: fix wrong buf address calculation when using xdp Nikolay Aleksandrov
2022-04-25 10:37 ` Nikolay Aleksandrov
2022-04-25 11:37 ` Xuan Zhuo
2022-04-25 11:37 ` Xuan Zhuo
2022-04-25 13:10 ` Daniel Borkmann [this message]
2022-04-25 13:10 ` Daniel Borkmann
2022-04-25 13:52 ` Michael S. Tsirkin
2022-04-25 13:52 ` Michael S. Tsirkin
2022-04-26 2:22 ` Jason Wang
2022-04-26 2:22 ` Jason Wang
2022-04-26 13:00 ` patchwork-bot+netdevbpf
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