[PATCH net] mpls: fix clearing of dead nh_flags on link up

[PATCH net] mpls: fix clearing of dead nh_flags on link up

[Roopa Prabhu]

From: Roopa Prabhu <roopa@cumulusnetworks.com>

recent fixes to use WRITE_ONCE for nh_flags on link up,
accidently ended up leaving the deadflags on a nh. This patch
fixes the WRITE_ONCE to use freshly evaluated nh_flags.

Fixes: 39eb8cd17588 ("net: mpls: rt_nhn_alive and nh_flags should be accessed using READ_ONCE")
Reported-by: Satish Ashok <sashok@cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
---
 net/mpls/af_mpls.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 94b3317..b51582d 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -1483,7 +1483,7 @@ static void mpls_ifup(struct net_device *dev, unsigned int flags)
 				continue;
 			alive++;
 			nh_flags &= ~flags;
-			WRITE_ONCE(nh->nh_flags, flags);
+			WRITE_ONCE(nh->nh_flags, nh_flags);
 		} endfor_nexthops(rt);
 
 		WRITE_ONCE(rt->rt_nhn_alive, alive);
-- 
1.9.1

Re: [PATCH net] mpls: fix clearing of dead nh_flags on link up

[David Ahern]

On 5/31/17 12:50 AM, Roopa Prabhu wrote:
> From: Roopa Prabhu <roopa@cumulusnetworks.com>
> 
> recent fixes to use WRITE_ONCE for nh_flags on link up,
> accidently ended up leaving the deadflags on a nh. This patch
> fixes the WRITE_ONCE to use freshly evaluated nh_flags.
> 
> Fixes: 39eb8cd17588 ("net: mpls: rt_nhn_alive and nh_flags should be accessed using READ_ONCE")
> Reported-by: Satish Ashok <sashok@cumulusnetworks.com>
> Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
> ---
>  net/mpls/af_mpls.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Acked-by: David Ahern <dsahern@gmail.com>

Re: [PATCH net] mpls: fix clearing of dead nh_flags on link up

[David Miller]

From: Roopa Prabhu <roopa@cumulusnetworks.com>
Date: Tue, 30 May 2017 23:50:36 -0700

> From: Roopa Prabhu <roopa@cumulusnetworks.com>
> 
> recent fixes to use WRITE_ONCE for nh_flags on link up,
> accidently ended up leaving the deadflags on a nh. This patch
> fixes the WRITE_ONCE to use freshly evaluated nh_flags.
> 
> Fixes: 39eb8cd17588 ("net: mpls: rt_nhn_alive and nh_flags should be accessed using READ_ONCE")
> Reported-by: Satish Ashok <sashok@cumulusnetworks.com>
> Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>

Applied, thanks.