Now we have range_in_vma_desc(), update remap_pfn_range_prepare() to check
whether the input range in contained within the specified VMA, so we can
fail at prepare time if an invalid range is specified.

This covers the I/O remap mmap actions also which ultimately call into this
function, and other mmap action types either already span the full VMA or
check this already.

Signed-off-by: Lorenzo Stoakes (Oracle) <[email protected]>
---
 mm/memory.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mm/memory.c b/mm/memory.c
index 849d5d9eeb83..de0dd17759e2 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3142,6 +3142,9 @@ int remap_pfn_range_prepare(struct vm_area_desc *desc)
        const bool is_cow = vma_desc_is_cow_mapping(desc);
        int err;
 
+       if (!range_in_vma_desc(desc, start, end))
+               return -EFAULT;
+
        err = get_remap_pgoff(is_cow, start, end, desc->start, desc->end, pfn,
                              &desc->pgoff);
        if (err)
-- 
2.53.0


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