Messages in this thread | | | Date | Tue, 20 Aug 2019 12:05:25 -0400 | From | Andrea Arcangeli <> | Subject | Re: [PATCH] userfaultfd_release: always remove uffd flags and clear vm_userfaultfd_ctx |
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On Tue, Aug 20, 2019 at 06:02:38PM +0200, Oleg Nesterov wrote: > userfaultfd_release() should clear vm_flags/vm_userfaultfd_ctx even > if mm->core_state != NULL. > > Otherwise a page fault can see userfaultfd_missing() == T and use an > already freed userfaultfd_ctx. > > Reported-by: Kefeng Wang <wangkefeng.wang@huawei.com> > Fixes: 04f5866e41fb ("coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping") > Cc: stable@vger.kernel.org > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > --- > fs/userfaultfd.c | 25 +++++++++++++------------ > 1 file changed, 13 insertions(+), 12 deletions(-)
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Thanks, Andrea
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