Messages in this thread |  | | From | Muchun Song <> | Date | Sun, 23 May 2021 10:45:11 +0800 | Subject | Re: [External] [PATCH] userfaultfd: hugetlbfs: fix new flag usage in error path |
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On Sat, May 22, 2021 at 7:40 AM Mike Kravetz <mike.kravetz@oracle.com> wrote: > > In commit d6995da31122 ("hugetlb: use page.private for hugetlb specific > page flags") the use of PagePrivate to indicate a reservation count > should be restored at free time was changed to the hugetlb specific flag > HPageRestoreReserve. Changes to a userfaultfd error path as well as a > VM_BUG_ON() in remove_inode_hugepages() were overlooked. > > Users could see incorrect hugetlb reserve counts if they experience an > error with a UFFDIO_COPY operation. Specifically, this would be the > result of an unlikely copy_huge_page_from_user error. There is not an > increased chance of hitting the VM_BUG_ON. > > Fixes: d6995da31122 ("hugetlb: use page.private for hugetlb specific page flags") > Cc: <stable@vger.kernel.org> > Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Thanks Mike.
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