Re: [PATCH] hugetlb: fix null-ptr-deref in hugetlb_vma_lock_write

[Rik van Riel]

On Mon, 2023-11-13 at 17:20 -0800, Mike Kravetz wrote:
> 
> Mask off low bit flags before checking for NULL pointer.  In
> addition,
> the reserve map only 'belongs' to the OWNER (parent in parent/child
> relationships) so also check for the OWNER flag.
> 
> Reported-by: syzbot+6ada951e7c0f7bc8a71e@xxxxxxxxxxxxxxxxxxxxxxxxx
> Closes:
> https://lore.kernel.org/linux-mm/00000000000078d1e00608d7878b@xxxxxxxxxx/
> Fixes: bf4916922c60 ("hugetlbfs: extend hugetlb_vma_lock to private
> VMAs")
> Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
> 

Reviewed-by: Rik van Riel <riel@xxxxxxxxxxx>

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