From 991b64b89b661c1d567c5737f37fd7a423ea12ba Mon Sep 17 00:00:00 2001 From: Iwona Winiarska Date: Wed, 4 Aug 2021 01:48:19 +0200 Subject: [PATCH] soc: aspeed: p2a-ctrl: Fix boundary check for mmap 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 Reviewed-by: Andrew Jeffery Tested-by: Andrew Jeffery Reviewed-by: Joel Stanley Signed-off-by: Joel Stanley Signed-off-by: Greg Kroah-Hartman --- drivers/soc/aspeed/aspeed-p2a-ctrl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/soc/aspeed/aspeed-p2a-ctrl.c b/drivers/soc/aspeed/aspeed-p2a-ctrl.c index b60fbeaffcbd0..20b5fb2a207cc 100644 --- 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 *file, struct vm_area_struct *vma) 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 */