From: Iwona Winiarska Date: Tue, 3 Aug 2021 23:48:18 +0000 (+0200) Subject: soc: aspeed: lpc-ctrl: Fix boundary check for mmap X-Git-Tag: v5.13.19~351 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=306b5b24496def5a2a9e18e9d945755052fb0fd4;p=thirdparty%2Fkernel%2Fstable.git soc: aspeed: lpc-ctrl: Fix boundary check for mmap commit b49a0e69a7b1a68c8d3f64097d06dabb770fec96 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: 6c4e97678501 ("drivers/misc: Add Aspeed LPC 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 --- diff --git a/drivers/soc/aspeed/aspeed-lpc-ctrl.c b/drivers/soc/aspeed/aspeed-lpc-ctrl.c index c557ffd0992c7..55e46fa6cf424 100644 --- a/drivers/soc/aspeed/aspeed-lpc-ctrl.c +++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c @@ -51,7 +51,7 @@ static int aspeed_lpc_ctrl_mmap(struct file *file, struct vm_area_struct *vma) unsigned long vsize = vma->vm_end - vma->vm_start; pgprot_t prot = vma->vm_page_prot; - if (vma->vm_pgoff + vsize > lpc_ctrl->mem_base + lpc_ctrl->mem_size) + if (vma->vm_pgoff + vma_pages(vma) > lpc_ctrl->mem_size >> PAGE_SHIFT) return -EINVAL; /* ast2400/2500 AHB accesses are not cache coherent */