diff options
| author | Eric Dumazet <edumazet@google.com> | 2021-04-13 05:41:35 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-08-04 12:23:44 +0200 |
| commit | d94d95ae0dd0086f465442fad48fbb2fa1bd7ed3 (patch) | |
| tree | fe6e9cdd18485413b1257ab14f79922505d87cdb /include/linux/skbuff.h | |
| parent | 16851e34b621bc7e652c508bb28c47948fb86958 (diff) | |
gro: ensure frag0 meets IP header alignment
commit 38ec4944b593fd90c5ef42aaaa53e66ae5769d04 upstream.
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>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/linux/skbuff.h')
| -rw-r--r-- | include/linux/skbuff.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 06176ef2a842..5f2e6451ece5 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -2789,6 +2789,15 @@ static inline void skb_propagate_pfmemalloc(struct page *page, } /** + * skb_frag_off() - Returns the offset of a skb fragment + * @frag: the paged fragment + */ +static inline unsigned int skb_frag_off(const skb_frag_t *frag) +{ + return frag->page_offset; +} + +/** * skb_frag_page - retrieve the page referred to by a paged fragment * @frag: the paged fragment * |