On Tue, 15 Feb 2022 12:19:22 -0800 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. > > ... > > --- 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); > } https://lore.kernel.org/all/00000000000072ef2c05d7f81950@xxxxxxxxxx/ It would be nice to have a Fixes: for this. Is it specific to process_mrelease(), or should we backport further?
