[PATCH 3.16 141/192] ipv4/fib: don't warn when primary address is missing if in_dev is dead

[Ben Hutchings]

3.16.49-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Paolo Abeni <pabeni@xxxxxxxxxx>

[ Upstream commit 391a20333b8393ef2e13014e6e59d192c5594471 ]

After commit fbd40ea0180a ("ipv4: Don't do expensive useless work
during inetdev destroy.") when deleting an interface,
fib_del_ifaddr() can be executed without any primary address
present on the dead interface.

The above is safe, but triggers some "bug: prim == NULL" warnings.

This commit avoids warning if the in_dev is dead

Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 net/ipv4/fib_frontend.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -797,7 +797,11 @@ void fib_del_ifaddr(struct in_ifaddr *if
 	if (ifa->ifa_flags & IFA_F_SECONDARY) {
 		prim = inet_ifa_byprefix(in_dev, any, ifa->ifa_mask);
 		if (prim == NULL) {
-			pr_warn("%s: bug: prim == NULL\n", __func__);
+			/* if the device has been deleted, we don't perform
+			 * address promotion
+			 */
+			if (!in_dev->dead)
+				pr_warn("%s: bug: prim == NULL\n", __func__);
 			return;
 		}
 		if (iprim && iprim != prim) {