From: Andrea Arcangeli aarcange@redhat.com
Upstream 04f5866e41fb70690e28397487d8bd8eea7d712a commit.
Signed-off-by: Michal Hocko mhocko@suse.com
Hi, this is based on the backport I have done for out 4.4 based distribution kernel. Please double check that I haven't missed anything before applying to the stable tree. I have also CCed Joel for the binder part which is not in the current upstream anymore but I believe it needs the check as well.
Review feedback welcome.
drivers/android/binder.c | 6 ++++++ fs/proc/task_mmu.c | 18 ++++++++++++++++++ fs/userfaultfd.c | 10 ++++++++-- include/linux/mm.h | 21 +++++++++++++++++++++ mm/huge_memory.c | 2 +- mm/mmap.c | 7 ++++++- 6 files changed, 60 insertions(+), 4 deletions(-)
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 260ce0e60187..1fb1cddbd19a 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -570,6 +570,12 @@ static int binder_update_page_range(struct binder_proc *proc, int allocate,
if (mm) { down_write(&mm->mmap_sem);
if (!mmget_still_valid(mm)) {if (allocate == 0)goto free_range;
Please cross check, free_range: should not end-up with modifications in vma.
goto err_no_vma;}- vma = proc->vma; if (vma && mm != proc->vma_vm_mm) { pr_err("%d: vma mm and task mm mismatch\n",