On Tue, Feb 15, 2022 at 12:19 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > After exit_mmap frees all vmas in the mm, mm->mmap needs to be reset, > otherwise it points to a vma that was freed and when reused leads to > a use-after-free bug. > > Reported-by: syzbot+2ccf63a4bd07cf39cab0@xxxxxxxxxxxxxxxxxxxxxxxxx > Suggested-by: Michal Hocko <mhocko@xxxxxxxx> > Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx> Looks good to me. Reviewed-by: Yang Shi <shy828301@xxxxxxxxx> > --- > mm/mmap.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/mmap.c b/mm/mmap.c > index 1e8fdb0b51ed..d445c1b9d606 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -3186,6 +3186,7 @@ void exit_mmap(struct mm_struct *mm) > vma = remove_vma(vma); > cond_resched(); > } > + mm->mmap = NULL; > mmap_write_unlock(mm); > vm_unacct_memory(nr_accounted); > } > -- > 2.35.1.265.g69c8d7142f-goog >
