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From 415e0feec4f927af0059f72a6831f6c5a104f0fc Mon Sep 17 00:00:00 2001
From: Hauke Mehrtens <hauke@hauke-m.de>
Date: Mon, 17 Jun 2019 00:13:08 +0200
Subject: [PATCH] MIPS: Fix bounds check virt_addr_valid

The bounds check used the uninitialized variable vaddr, it should use
the given parameter kaddr instead. When using the uninitialized value
the compiler assumed it to be 0 and optimized this function to just
return 0 in all cases.

This should make the function check the range of the given address and
only do the page map check in case it is in the expected range of
virtual addresses.

Fixes: 074a1e1167af ("MIPS: Bounds check virt_addr_valid")
Cc: stable@vger.kernel.org # v4.12+
Cc: Paul Burton <paul.burton@mips.com>
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
---
 arch/mips/mm/mmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/mm/mmap.c
+++ b/arch/mips/mm/mmap.c
@@ -203,7 +203,7 @@ unsigned long arch_randomize_brk(struct
 
 int __virt_addr_valid(const volatile void *kaddr)
 {
-	unsigned long vaddr = (unsigned long)vaddr;
+	unsigned long vaddr = (unsigned long)kaddr;
 
 	if ((vaddr < PAGE_OFFSET) || (vaddr >= MAP_BASE))
 		return 0;