From: Cho KyongHo <pullip.cho@samsung.com>
Date: Thu, 5 Jan 2017 13:59:33 +0000 (+0900)
Subject: [COMMON] iommu/exynos: fix possible NULL pointer dereference
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5ea147f9719ed80234ff3dcf8b204319e1bc045e;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

[COMMON] iommu/exynos: fix possible NULL pointer dereference

find_vma() may return NULL. It should be checked even though
exynos_iovmm_map_userptr() requires the callers to acquire mmap_sem.

SVACE WGID 87553

Change-Id: Ice3239234dc46177bce5963444f0c4cbc094fe40
Signed-off-by: Cho KyongHo <pullip.cho@samsung.com>
---

diff --git a/drivers/iommu/exynos-iovmm.c b/drivers/iommu/exynos-iovmm.c
index b61ad53f9a6b..178d942d8b34 100644
--- a/drivers/iommu/exynos-iovmm.c
+++ b/drivers/iommu/exynos-iovmm.c
@@ -513,7 +513,7 @@ dma_addr_t exynos_iovmm_map_userptr(struct device *dev, unsigned long vaddr,
 	struct exynos_vm_region *region;
 
 	vma = find_vma(current->mm, vaddr);
-	if (vaddr < vma->vm_start) {
+	if (!vma || (vaddr < vma->vm_start)) {
 		dev_err(dev, "%s: invalid address %#lx\n", __func__, vaddr);
 		goto err;
 	}