From: Linus Torvalds Date: Fri, 19 Oct 2012 20:37:57 +0000 (-0700) Subject: remap_file_pages: correctly handle the case of a NULL vm_ops pointer X-Git-Tag: upstream/snapshot3+hdmi~6381 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=deb521c44fa529b24cc78a64702757a683f82487;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git remap_file_pages: correctly handle the case of a NULL vm_ops pointer In commit 0b173bc4daa8 ("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 Cc: Konstantin Khlebnikov Cc: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/fremap.c b/mm/fremap.c index 3899a86..a0aaf0e 100644 --- a/mm/fremap.c +++ b/mm/fremap.c @@ -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)