Commit deb521c4 authored Oct 19, 2012 by Linus Torvalds

remap_file_pages: correctly handle the case of a NULL vm_ops pointer



In commit 0b173bc4 ("mm: kill vma flag VM_CAN_NONLINEAR") we
replaced the VM_CAN_NONLINEAR test with checking whether the mapping has
a '->remap_pages()' vm operation, but there is no guarantee that there
it even has a vm_ops pointer at all.

Add the appropriate test for NULL vm_ops.

Reported-by: Sasha Levin <levinsasha928@gmail.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 17dbe27d

mm/fremap.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -169,7 +169,7 @@ SYSCALL_DEFINE5(remap_file_pages, unsigned long, start, unsigned long, size,
		if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR))
		goto out;

		if (!vma->vm_ops->remap_pages)
		if (!vma->vm_ops \|\| !vma->vm_ops->remap_pages)
		goto out;

		if (start < vma->vm_start \|\| start + size > vma->vm_end)

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