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authorIwona Winiarska <iwona.winiarska@intel.com>2021-08-04 02:48:19 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-09-18 14:40:08 +0300
commit01e6c64bbc5d3553421cf217afef1ae47744edda (patch)
tree42bbb133d9e7d64eb4ecbb2189c69f9a095698f5
parent3fdf2feb6cbe76c6867224ed8527b356e805352c (diff)
downloadlinux-01e6c64bbc5d3553421cf217afef1ae47744edda.tar.xz
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 <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>
-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 */