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author | Eric Dumazet <edumazet@google.com> | 2021-04-13 05:41:35 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2021-04-13 15:09:31 -0700 |
commit | 38ec4944b593fd90c5ef42aaaa53e66ae5769d04 (patch) | |
tree | ada126e3929b87d7b29b858478f5b8f5bf70475c /drivers/net/xen-netback | |
parent | b166a20b07382b8bc1dcee2a448715c9c2c81b5b (diff) | |
download | linux-38ec4944b593fd90c5ef42aaaa53e66ae5769d04.tar.gz linux-38ec4944b593fd90c5ef42aaaa53e66ae5769d04.tar.bz2 linux-38ec4944b593fd90c5ef42aaaa53e66ae5769d04.zip |
gro: ensure frag0 meets IP header alignment
After commit 0f6925b3e8da ("virtio_net: Do not pull payload in skb->head")
Guenter Roeck reported one failure in his tests using sh architecture.
After much debugging, we have been able to spot silent unaligned accesses
in inet_gro_receive()
The issue at hand is that upper networking stacks assume their header
is word-aligned. Low level drivers are supposed to reserve NET_IP_ALIGN
bytes before the Ethernet header to make that happen.
This patch hardens skb_gro_reset_offset() to not allow frag0 fast-path
if the fragment is not properly aligned.
Some arches like x86, arm64 and powerpc do not care and define NET_IP_ALIGN
as 0, this extra check will be a NOP for them.
Note that if frag0 is not used, GRO will call pskb_may_pull()
as many times as needed to pull network and transport headers.
Fixes: 0f6925b3e8da ("virtio_net: Do not pull payload in skb->head")
Fixes: 78a478d0efd9 ("gro: Inline skb_gro_header and cache frag0 virtual address")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/xen-netback')
0 files changed, 0 insertions, 0 deletions