diff options
Diffstat (limited to 'net/mctp/route.c')
| -rw-r--r-- | net/mctp/route.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/net/mctp/route.c b/net/mctp/route.c index 1f3dccbb7aed..b19c63a5691a 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -998,14 +998,29 @@ int mctp_route_lookup(struct net *net, unsigned int dnet, mtu = mtu ?: rt->mtu; if (rt->dst_type == MCTP_ROUTE_DIRECT) { - mctp_eid_t saddr = mctp_dev_saddr(rt->dev); + mctp_eid_t saddr; + + /* rt->dev may be going away concurrently: its last + * reference is dropped in mctp_dev_put(), which frees + * mdev->addrs that mctp_dev_saddr() reads, and + * mctp_dst_from_route() takes a reference on it. Pin + * it before use, and skip a device that is already + * dead rather than resurrecting it. + */ + if (!refcount_inc_not_zero(&rt->dev->refs)) + break; + + saddr = mctp_dev_saddr(rt->dev); /* cannot do gateway-ed routes without a src */ - if (saddr == MCTP_ADDR_NULL && depth != 0) + if (saddr == MCTP_ADDR_NULL && depth != 0) { + mctp_dev_put(rt->dev); break; + } if (dst) mctp_dst_from_route(dst, daddr, saddr, mtu, rt); + mctp_dev_put(rt->dev); rc = 0; break; |