@@ -442,6 +442,7 @@ void fib6_select_path(const struct net *net, struct fib6_result *res,
{
struct fib6_info *first, *match = res->f6i;
struct fib6_info *sibling;
+ int hash;
if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
goto out;
@@ -468,7 +469,8 @@ void fib6_select_path(const struct net *net, struct fib6_result *res,
if (!first)
goto out;
- if (fl6->mp_hash <= atomic_read(&first->fib6_nh->fib_nh_upper_bound) &&
+ hash = fl6->mp_hash;
+ if (hash <= atomic_read(&first->fib6_nh->fib_nh_upper_bound) &&
rt6_score_route(first->fib6_nh, first->fib6_flags, oif,
strict) >= 0) {
match = first;
@@ -481,7 +483,7 @@ void fib6_select_path(const struct net *net, struct fib6_result *res,
int nh_upper_bound;
nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
- if (fl6->mp_hash > nh_upper_bound)
+ if (hash > nh_upper_bound)
continue;
if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
break;
Nexthops whose link is down are not supposed to be considered during path selection when the "ignore_routes_with_linkdown" sysctl is set. This is done by assigning them a negative region boundary. However, when comparing the computed hash (unsigned) with the region boundary (signed), the negative region boundary is treated as unsigned, resulting in incorrect nexthop selection. Fix by treating the computed hash as signed. Note that the computed hash is always in range of [0, 2^31 - 1]. Fixes: 3d709f69a3e7 ("ipv6: Use hash-threshold instead of modulo-N") Signed-off-by: Ido Schimmel <idosch@nvidia.com> --- net/ipv6/route.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)