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| author | Jason Wang <jasowang@redhat.com> | 2017-10-27 11:05:44 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-10-28 19:05:28 +0900 |
| commit | 63b9ab65bd76e5de6479bb14b4014b64aa1a317a (patch) | |
| tree | 3822be64ed1349f2d394198b022fe482ddaa47e7 | |
| parent | 8ab190fbe96178449d8195c3582aa10ce684c386 (diff) | |
| download | lwn-63b9ab65bd76e5de6479bb14b4014b64aa1a317a.tar.gz lwn-63b9ab65bd76e5de6479bb14b4014b64aa1a317a.zip | |
tuntap: properly align skb->head before building skb
An unaligned alloc_frag->offset caused by previous allocation will
result an unaligned skb->head. This will lead unaligned
skb_shared_info and then unaligned dataref which requires to be
aligned for accessing on some architecture. Fix this by aligning
alloc_frag->offset before the frag refilling.
Fixes: 0bbd7dad34f8 ("tun: make tun_build_skb() thread safe")
Cc: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: Wei Wei <dotweiba@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Reported-by: Wei Wei <dotweiba@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/tun.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index b9973fb868b7..5550f56cb895 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1286,6 +1286,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, buflen += SKB_DATA_ALIGN(len + pad); rcu_read_unlock(); + alloc_frag->offset = ALIGN((u64)alloc_frag->offset, SMP_CACHE_BYTES); if (unlikely(!skb_page_frag_refill(buflen, alloc_frag, GFP_KERNEL))) return ERR_PTR(-ENOMEM); |