From: jie@chenjie6@huwei.com <jie@chenjie6@huwei.com>
Date: Sat, 11 Aug 2018 00:23:06 +0000 (-0700)
Subject: mm/memory.c: check return value of ioremap_prot
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=fbee7b5b8c28ed02b6d6603eef27730c148a4481;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git

mm/memory.c: check return value of ioremap_prot

[ Upstream commit 24eee1e4c47977bdfb71d6f15f6011e7b6188d04 ]

ioremap_prot() can return NULL which could lead to an oops.

Link: http://lkml.kernel.org/r/1533195441-58594-1-git-send-email-chenjie6@huawei.com
Signed-off-by: chen jie <chenjie6@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: chenjie <chenjie6@huawei.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/mm/memory.c b/mm/memory.c
index d5bb1465d30c..42db644f5ec4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3701,6 +3701,9 @@ int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
 		return -EINVAL;
 
 	maddr = ioremap_prot(phys_addr, PAGE_ALIGN(len + offset), prot);
+	if (!maddr)
+		return -ENOMEM;
+
 	if (write)
 		memcpy_toio(maddr + offset, buf, len);
 	else