Commit 30bfd930 authored by Peter Oskolkov's avatar Peter Oskolkov Committed by David S. Miller

net/ipv6: do not copy dst flags on rt init

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: 3b6761d1 ("net/ipv6: Move dst flags to booleans in fib entries")
Cc: David Ahern <>
Acked-by: default avatarWei Wang <>
Signed-off-by: default avatarPeter Oskolkov <>
Reviewed-by: default avatarDavid Ahern <>
Signed-off-by: default avatarDavid S. Miller <>
parent 922005c7
......@@ -946,8 +946,6 @@ static void ip6_rt_init_dst_reject(struct rt6_info *rt, struct fib6_info *ort)
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);
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