From: Roopa Prabhu <ro...@cumulusnetworks.com>
Date: Thu, 7 Apr 2016 21:28:38 -0700
> From: Roopa Prabhu <ro...@cumulusnetworks.com>
>
> find_outdev calls inet{,6}_fib_lookup_dev() or dev_get_by_index() to
> find the output device. In case of an error, inet{,6}_fib_lookup_dev()
> returns error pointer and dev_get_by_index() returns NULL. But the function
> only checks for NULL and thus can end up calling dev_put on an ERR_PTR.
> This patch adds an additional check for err ptr after the NULL check.
>
> Before: Trying to add an mpls route with no oif from user, no available
> path to 10.1.1.8 and no default route:
> $ip -f mpls route add 100 as 200 via inet 10.1.1.8
> [ 822.337195] BUG: unable to handle kernel NULL pointer dereference at
> 00000000000003a3
...
> After patch:
> $ip -f mpls route add 100 as 200 via inet 10.1.1.8
> RTNETLINK answers: Network is unreachable
>
> Signed-off-by: Roopa Prabhu <ro...@cumulusnetworks.com>
> Reported-by: David Miller <da...@davemloft.net>
Applied, thanks.
