lkml.org 
[lkml]   [2016]   [Jan]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.10 37/53] net: possible use after free in dst_release
    Date
    3.10-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Francesco Ruggeri <fruggeri@aristanetworks.com>

    [ Upstream commit 07a5d38453599052aff0877b16bb9c1585f08609 ]

    dst_release should not access dst->flags after decrementing
    __refcnt to 0. The dst_entry may be in dst_busy_list and
    dst_gc_task may dst_destroy it before dst_release gets a chance
    to access dst->flags.

    Fixes: d69bbf88c8d0 ("net: fix a race in dst_release()")
    Fixes: 27b75c95f10d ("net: avoid RCU for NOCACHE dst")
    Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
    Acked-by: Eric Dumazet <edumazet@google.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    ---
    net/core/dst.c | 3 ++-
    1 file changed, 2 insertions(+), 1 deletion(-)

    --- a/net/core/dst.c
    +++ b/net/core/dst.c
    @@ -280,10 +280,11 @@ void dst_release(struct dst_entry *dst)
    {
    if (dst) {
    int newrefcnt;
    + unsigned short nocache = dst->flags & DST_NOCACHE;

    newrefcnt = atomic_dec_return(&dst->__refcnt);
    WARN_ON(newrefcnt < 0);
    - if (!newrefcnt && unlikely(dst->flags & DST_NOCACHE))
    + if (!newrefcnt && unlikely(nocache))
    call_rcu(&dst->rcu_head, dst_destroy_rcu);
    }
    }

    \
     
     \ /
      Last update: 2016-01-27 21:21    [W:3.568 / U:0.236 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site