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(-)
diff --git a/arch/mips/mm/mmap.c b/arch/mips/mm/mmap.c index 50ee7213b432..d79f2b432318 100644 --- a/arch/mips/mm/mmap.c +++ b/arch/mips/mm/mmap.c @@ -203,7 +203,7 @@ unsigned long arch_randomize_brk(struct mm_struct *mm)
bool __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 false;