4.18-stable review patch. If anyone has any objections, please let me know.
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From: Peter Oskolkov posk@google.com
[ Upstream commit 30bfd93062814d6767e452a8f5ddcd97f7e38c7e ]
DST_NOCOUNT in dst_entry::flags tracks whether the entry counts toward route cache size (net->ipv6.sysctl.ip6_rt_max_size).
If the flag is NOT set, dst_ops::pcpuc_entries counter is incremented in dist_init() and decremented in dst_destroy().
This flag is tied to allocation/deallocation of dst_entry and should not be copied from another dst/route. Otherwise it can happen that dst_ops::pcpuc_entries counter grows until no new routes can be allocated because the counter reached ip6_rt_max_size due to DST_NOCOUNT not set and thus no counter decrements on gc-ed routes.
Fixes: 3b6761d18bc1 ("net/ipv6: Move dst flags to booleans in fib entries") Cc: David Ahern dsahern@gmail.com Acked-by: Wei Wang weiwan@google.com Signed-off-by: Peter Oskolkov posk@google.com Reviewed-by: David Ahern dsahern@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/route.c | 2 -- 1 file changed, 2 deletions(-)
--- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -946,8 +946,6 @@ static void ip6_rt_init_dst_reject(struc
static void ip6_rt_init_dst(struct rt6_info *rt, struct fib6_info *ort) { - rt->dst.flags |= fib6_info_dst_flags(ort); - if (ort->fib6_flags & RTF_REJECT) { ip6_rt_init_dst_reject(rt, ort); return;