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authorIwona Winiarska <iwona.winiarska@intel.com>2021-08-04 01:48:19 +0200
committerJoel Stanley <joel@jms.id.au>2021-08-17 18:00:44 +0930
commit8b07e990fb254fcbaa919616ac77f981cb48c73d (patch)
treed293d1a79b058fdd9e62887a0ca9a146077aa9ba
parentsoc: aspeed: lpc-ctrl: Fix boundary check for mmap (diff)
downloadlinux-dev-8b07e990fb254fcbaa919616ac77f981cb48c73d.tar.xz
linux-dev-8b07e990fb254fcbaa919616ac77f981cb48c73d.zip
soc: aspeed: p2a-ctrl: Fix boundary check for mmap
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>
-rw-r--r--drivers/soc/aspeed/aspeed-p2a-ctrl.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/soc/aspeed/aspeed-p2a-ctrl.c b/drivers/soc/aspeed/aspeed-p2a-ctrl.c
index b60fbeaffcbd..20b5fb2a207c 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 */