From: Hauke Mehrtens hauke@hauke-m.de
commit d6ed083f5cc621e15c15b56c3b585fd524dbcb0f upstream.
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 Signed-off-by: Paul Burton paul.burton@mips.com Cc: ralf@linux-mips.org Cc: jhogan@kernel.org Cc: f4bug@amsat.org Cc: linux-mips@vger.kernel.org Cc: ysu@wavecomp.com Cc: jcristau@debian.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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;