ipv6: Initialize rt6_info properly in ip6_blackhole_route()

ip6_blackhole_route() does not initialize the newly allocated
rt6_info properly.  This patch:
1. Call rt6_info_init() to initialize rt6i_siblings and rt6i_uncached

2. The current rt->dst._metrics init code is incorrect:
   - 'rt->dst._metrics = ort->dst._metris' is not always safe
   - Not sure what dst_copy_metrics() is trying to do here
     considering ip6_rt_blackhole_cow_metrics() always returns
     NULL

   Fix:
   - Always do dst_copy_metrics()
   - Replace ip6_rt_blackhole_cow_metrics() with
     dst_cow_metrics_generic()

3. Mask out the RTF_PCPU bit from the newly allocated blackhole route.
   This bug triggers an oops (reported by Phil Sutter) in rt6_get_cookie().
   It is because RTF_PCPU is set while rt->dst.from is NULL.

Fixes: d52d3997f843 ("ipv6: Create percpu rt6_info")
Signed-off-by: Martin KaFai Lau <[email protected]>
Reported-by: Phil Sutter <[email protected]>
Tested-by: Phil Sutter <[email protected]>
Cc: Hannes Frederic Sowa <[email protected]>
Cc: Julian Anastasov <[email protected]>
Cc: Phil Sutter <[email protected]>
Cc: Steffen Klassert <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions