From: Wei Wang <wei...@google.com>
Date: Thu, 4 Oct 2018 10:12:37 -0700
> From: Wei Wang <wei...@google.com>
>
> In rawv6_send_hdrinc(), in order to avoid an extra dst_hold(), we
> directly assign the dst to skb and set passed in dst to NULL to avoid
> double free.
> However, in error case, we free skb and then do stats update with the
> dst pointer passed in. This causes use-after-free on the dst.
> Fix it by taking rcu read lock right before dst could get released to
> make sure dst does not get freed until the stats update is done.
> Note: we don't have this issue in ipv4 cause dst is not used for stats
> update in v4.
>
> Syzkaller reported following crash:
...
> Fixes: 1789a640f556 ("raw: avoid two atomics in xmit")
> Signed-off-by: Wei Wang <wei...@google.com>
> Signed-off-by: Eric Dumazet <eduma...@google.com>
Applied and queued up for -stable, thanks.
