lkml.org 
[lkml]   [2021]   [Sep]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.10 024/306] soc: aspeed: lpc-ctrl: Fix boundary check for mmap
Date
From: Iwona Winiarska <iwona.winiarska@intel.com>

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 <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-lpc-ctrl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/soc/aspeed/aspeed-lpc-ctrl.c
+++ b/drivers/soc/aspeed/aspeed-lpc-ctrl.c
@@ -46,7 +46,7 @@ static int aspeed_lpc_ctrl_mmap(struct f
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 */

\
 
 \ /
  Last update: 2021-09-16 18:06    [W:1.541 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site