From: Mahesh Bandewar maheshb@google.com
[ Upstream commit 66eb9f86e50547ec2a8ff7a75997066a74ef584b ]
Every address gets added with TENTATIVE flag even for the addresses with IFA_F_NODAD flag and dad-work is scheduled for them. During this DAD process we realize it's an address with NODAD and complete the process without sending any probe. However the TENTATIVE flags stays on the address for sometime enough to cause misinterpretation when we receive a NS. While processing NS, if the address has TENTATIVE flag, we mark it DADFAILED and endup with an address that was originally configured as NODAD with DADFAILED.
We can't avoid scheduling dad_work for addresses with NODAD but we can avoid adding TENTATIVE flag to avoid this racy situation.
Signed-off-by: Mahesh Bandewar maheshb@google.com Acked-by: David Ahern dsahern@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- net/ipv6/addrconf.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 92174881844d..0613be57513e 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -957,7 +957,10 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, INIT_HLIST_NODE(&ifa->addr_lst); ifa->scope = scope; ifa->prefix_len = pfxlen; - ifa->flags = flags | IFA_F_TENTATIVE; + ifa->flags = flags; + /* No need to add the TENTATIVE flag for addresses with NODAD */ + if (!(flags & IFA_F_NODAD)) + ifa->flags |= IFA_F_TENTATIVE; ifa->valid_lft = valid_lft; ifa->prefered_lft = prefered_lft; ifa->cstamp = ifa->tstamp = jiffies;