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> --- 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
