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SubjectRe: [PATCH 3/5] uprobes: fix overflow in vma_address/find_active_uprobe
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On Sun, 2012-07-08 at 22:30 +0200, Oleg Nesterov wrote:
> vma->vm_pgoff is "unsigned long", it should be promoted to loff_t
> before the multiplication to avoid the overflow.
[]
> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
[]
> @@ -117,7 +117,7 @@ static loff_t vma_address(struct vm_area_struct *vma, loff_t offset)
> loff_t vaddr;
>
> vaddr = vma->vm_start + offset;
> - vaddr -= vma->vm_pgoff << PAGE_SHIFT;
> + vaddr -= (loff_t)vma->vm_pgoff << PAGE_SHIFT;
>
> return vaddr;
> }
> @@ -1450,7 +1450,7 @@ static struct uprobe *find_active_uprobe(unsigned long bp_vaddr, int *is_swbp)
>
> inode = vma->vm_file->f_mapping->host;
> offset = bp_vaddr - vma->vm_start;
> - offset += (vma->vm_pgoff << PAGE_SHIFT);
> + offset += ((loff_t)vma->vm_pgoff << PAGE_SHIFT);

It's be nice to take remove the unnecessary parenthesis
and make it consistent with the vaddr use above it too.




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