From: Iwona Winiarska iwona.winiarska@intel.com
commit 8b07e990fb254fcbaa919616ac77f981cb48c73d upstream.
The check mixes pages (vm_pgoff) with bytes (vm_start, vm_end) on one side of the comparison, and uses resource address (rather than just the resource size) on the other side of the comparison. This can allow malicious userspace to easily bypass the boundary check and map pages that are located outside memory-region reserved by the driver.
Fixes: 01c60dcea9f7 ("drivers/misc: Add Aspeed P2A control driver") Cc: stable@vger.kernel.org Signed-off-by: Iwona Winiarska iwona.winiarska@intel.com Reviewed-by: Andrew Jeffery andrew@aj.id.au Tested-by: Andrew Jeffery andrew@aj.id.au Reviewed-by: Joel Stanley joel@aj.id.au Signed-off-by: Joel Stanley joel@jms.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/soc/aspeed/aspeed-p2a-ctrl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/soc/aspeed/aspeed-p2a-ctrl.c +++ b/drivers/soc/aspeed/aspeed-p2a-ctrl.c @@ -110,7 +110,7 @@ static int aspeed_p2a_mmap(struct file * vsize = vma->vm_end - vma->vm_start; prot = vma->vm_page_prot;
- if (vma->vm_pgoff + vsize > ctrl->mem_base + ctrl->mem_size) + if (vma->vm_pgoff + vma_pages(vma) > ctrl->mem_size >> PAGE_SHIFT) return -EINVAL;
/* ast2400/2500 AHB accesses are not cache coherent */