From: Parav Pandit Date: Wed, 7 Mar 2018 06:07:41 +0000 (+0200) Subject: IB/core: Fix possible crash to access NULL netdev X-Git-Tag: v6.6-pxa1908~14647^2~5 X-Git-Url: https://git.dujemihanovic.xyz/?a=commitdiff_plain;h=bb7f8f199c354c4cf155b1d6d55f86eaaed7fa5a;p=linux.git IB/core: Fix possible crash to access NULL netdev resolved_dev returned might be NULL as ifindex is transient number. Ignoring NULL check of resolved_dev might crash the kernel. Therefore perform NULL check before accessing resolved_dev. Additionally rdma_resolve_ip_route() invokes addr_resolve() which performs check and address translation for loopback ifindex. Therefore, checking it again in rdma_resolve_ip_route() is not helpful. Therefore, the code is simplified to avoid IFF_LOOPBACK check. Fixes: 200298326b27 ("IB/core: Validate route when we init ah") Reviewed-by: Daniel Jurgens Signed-off-by: Parav Pandit Signed-off-by: Leon Romanovsky Signed-off-by: Doug Ledford --- diff --git a/drivers/infiniband/core/sa_query.c b/drivers/infiniband/core/sa_query.c index 8cf15d4a8ac4..9f029a1ca5ea 100644 --- a/drivers/infiniband/core/sa_query.c +++ b/drivers/infiniband/core/sa_query.c @@ -1291,10 +1291,9 @@ int ib_init_ah_attr_from_path(struct ib_device *device, u8 port_num, resolved_dev = dev_get_by_index(dev_addr.net, dev_addr.bound_dev_if); - if (resolved_dev->flags & IFF_LOOPBACK) { - dev_put(resolved_dev); - resolved_dev = idev; - dev_hold(resolved_dev); + if (!resolved_dev) { + dev_put(idev); + return -ENODEV; } ndev = ib_get_ndev_from_path(rec); rcu_read_lock();