This is a note to let you know that I've just added the patch titled
soc: aspeed: p2a-ctrl: Fix boundary check for mmap
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
soc-aspeed-p2a-ctrl-fix-boundary-check-for-mmap.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 8b07e990fb254fcbaa919616ac77f981cb48c73d Mon Sep 17 00:00:00 2001
From: Iwona Winiarska <iwona.winiarska@xxxxxxxxx>
Date: Wed, 4 Aug 2021 01:48:19 +0200
Subject: soc: aspeed: p2a-ctrl: Fix boundary check for mmap
From: Iwona Winiarska <iwona.winiarska@xxxxxxxxx>
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@xxxxxxxxxxxxxxx
Signed-off-by: Iwona Winiarska <iwona.winiarska@xxxxxxxxx>
Reviewed-by: Andrew Jeffery <andrew@xxxxxxxx>
Tested-by: Andrew Jeffery <andrew@xxxxxxxx>
Reviewed-by: Joel Stanley <joel@xxxxxxxx>
Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 */
Patches currently in stable-queue which might be from iwona.winiarska@xxxxxxxxx are
queue-5.4/soc-aspeed-lpc-ctrl-fix-boundary-check-for-mmap.patch
queue-5.4/soc-aspeed-p2a-ctrl-fix-boundary-check-for-mmap.patch
