Messages in this thread | | | Date | Mon, 22 Apr 2024 17:09:26 +0200 | Subject | Re: [PATCH] mm/userfaultfd: Reset ptes when close() for wr-protected ones | From | David Hildenbrand <> |
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On 22.04.24 15:33, Peter Xu wrote: > Userfaultfd unregister includes a step to remove wr-protect bits from all > the relevant pgtable entries, but that only covered an explicit > UFFDIO_UNREGISTER ioctl, not a close() on the userfaultfd itself. Cover > that too. > > Link: https://lore.kernel.org/all/000000000000ca4df20616a0fe16@google.com/ > Analyzed-by: David Hildenbrand <david@redhat.com> > Reported-by: syzbot+d8426b591c36b21c750e@syzkaller.appspotmail.com > Signed-off-by: Peter Xu <peterx@redhat.com> > --- > fs/userfaultfd.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c > index 3e6ddda6f159..d2c3879745e5 100644 > --- a/fs/userfaultfd.c > +++ b/fs/userfaultfd.c > @@ -898,6 +898,10 @@ static int userfaultfd_release(struct inode *inode, struct file *file) > prev = vma; > continue; > } > + /* Reset ptes for the whole vma range if wr-protected */ > + if (userfaultfd_wp(vma)) > + uffd_wp_range(vma, vma->vm_start, > + vma->vm_end - vma->vm_start, false); > new_flags = vma->vm_flags & ~__VM_UFFD_FLAGS; > vma = vma_modify_flags_uffd(&vmi, prev, vma, vma->vm_start, > vma->vm_end, new_flags,
LGTM
Reviewed-by: David Hildenbrand <david@redhat.com>
-- Cheers,
David / dhildenb
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