1. 05 5月, 2019 2 次提交
    • M
      ipv6: A few fixes on dereferencing rt->from · 7ea4f000
      Martin KaFai Lau 提交于
      [ Upstream commit 886b7a50100a50f1cbd08a6f8ec5884dfbe082dc ]
      
      It is a followup after the fix in
      commit 9c69a1320515 ("route: Avoid crash from dereferencing NULL rt->from")
      
      rt6_do_redirect():
      1. NULL checking is needed on rt->from because a parallel
         fib6_info delete could happen that sets rt->from to NULL.
         (e.g. rt6_remove_exception() and fib6_drop_pcpu_from()).
      
      2. fib6_info_hold() is not enough.  Same reason as (1).
         Meaning, holding dst->__refcnt cannot ensure
         rt->from is not NULL or rt->from->fib6_ref is not 0.
      
         Instead of using fib6_info_hold_safe() which ip6_rt_cache_alloc()
         is already doing, this patch chooses to extend the rcu section
         to keep "from" dereference-able after checking for NULL.
      
      inet6_rtm_getroute():
      1. NULL checking is also needed on rt->from for a similar reason.
         Note that inet6_rtm_getroute() is using RTNL_FLAG_DOIT_UNLOCKED.
      
      Fixes: a68886a6 ("net/ipv6: Make from in rt6_info rcu protected")
      Signed-off-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NWei Wang <weiwan@google.com>
      Reviewed-by: NDavid Ahern <dsahern@gmail.com>
      Reviewed-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7ea4f000
    • S
      ipv4: ip_do_fragment: Preserve skb_iif during fragmentation · 3f611a47
      Shmulik Ladkani 提交于
      [ Upstream commit d2f0c961148f65bc73eda72b9fa3a4e80973cb49 ]
      
      Previously, during fragmentation after forwarding, skb->skb_iif isn't
      preserved, i.e. 'ip_copy_metadata' does not copy skb_iif from given
      'from' skb.
      
      As a result, ip_do_fragment's creates fragments with zero skb_iif,
      leading to inconsistent behavior.
      
      Assume for example an eBPF program attached at tc egress (post
      forwarding) that examines __sk_buff->ingress_ifindex:
       - the correct iif is observed if forwarding path does not involve
         fragmentation/refragmentation
       - a bogus iif is observed if forwarding path involves
         fragmentation/refragmentatiom
      
      Fix, by preserving skb_iif during 'ip_copy_metadata'.
      Signed-off-by: NShmulik Ladkani <shmulik.ladkani@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3f611a47
  2. 04 5月, 2019 38 次提交