diff --git a/net/ipv6/route.c b/net/ipv6/route.c index d6fc22f7d7a6..575bd0f1b008 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1667,6 +1667,7 @@ static int rt6_insert_exception(struct rt6_info *nrt, struct in6_addr *src_key = NULL; struct rt6_exception *rt6_ex; struct fib6_nh *nh = res->nh; + int max_depth; int err = 0; spin_lock_bh(&rt6_exception_lock); @@ -1721,7 +1722,9 @@ static int rt6_insert_exception(struct rt6_info *nrt, bucket->depth++; net->ipv6.rt6_stats->fib_rt_cache++; - if (bucket->depth > FIB6_MAX_DEPTH) + /* Randomize max depth to avoid some side channels attacks. */ + max_depth = FIB6_MAX_DEPTH + prandom_u32_max(FIB6_MAX_DEPTH); + while (bucket->depth > max_depth) rt6_exception_remove_oldest(bucket); out: