From: Leon Romanovsky <leonro@mellanox.com>
Date: Sun, 1 Jul 2018 19:36:24 +0300
Subject: RDMA/i40w: Hold read semaphore while looking after VMA
Patch-mainline: v4.19-rc1
Git-commit: 5d9a2b0e28759e319a623da33940dbb3ce952b7d
References: bsc#1058659 FATE#322535

VMA lookup is supposed to be performed while mmap_sem is held.

Fixes: f26c7c83395b ("i40iw: Add 2MB page support")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/infiniband/hw/i40iw/i40iw_verbs.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/infiniband/hw/i40iw/i40iw_verbs.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_verbs.c
@@ -1426,6 +1426,7 @@ static void i40iw_set_hugetlb_values(u64
 	struct vm_area_struct *vma;
 	struct hstate *h;
 
+	down_read(&current->mm->mmap_sem);
 	vma = find_vma(current->mm, addr);
 	if (vma && is_vm_hugetlb_page(vma)) {
 		h = hstate_vma(vma);
@@ -1434,6 +1435,7 @@ static void i40iw_set_hugetlb_values(u64
 			iwmr->page_msk = huge_page_mask(h);
 		}
 	}
+	up_read(&current->mm->mmap_sem);
 }
 
 /**