From: Todd Kjos <tkjos@xxxxxxxxxxx>
This reverts commit 6bf7d3c5c0c5dad650bfc4345ed553c18b69d59e.
The commit message is for a different patch. Reverting and then adding
the same patch back with the correct commit message.
Reported-by: Ben Hutchings <ben.hutchings@xxxxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.19
Signed-off-by: Todd Kjos <tkjos@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/android/binder_alloc.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -958,13 +958,14 @@ enum lru_status binder_alloc_free_page(s
index = page - alloc->pages;
page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
-
- mm = alloc->vma_vm_mm;
- if (!mmget_not_zero(mm))
- goto err_mmget;
- if (!down_write_trylock(&mm->mmap_sem))
- goto err_down_write_mmap_sem_failed;
vma = binder_alloc_get_vma(alloc);
+ if (vma) {
+ if (!mmget_not_zero(alloc->vma_vm_mm))
+ goto err_mmget;
+ mm = alloc->vma_vm_mm;
+ if (!down_write_trylock(&mm->mmap_sem))
+ goto err_down_write_mmap_sem_failed;
+ }
list_lru_isolate(lru, item);
spin_unlock(lock);
@@ -977,9 +978,10 @@ enum lru_status binder_alloc_free_page(s
PAGE_SIZE);
trace_binder_unmap_user_end(alloc, index);
+
+ up_write(&mm->mmap_sem);
+ mmput(mm);
}
- up_write(&mm->mmap_sem);
- mmput(mm);
trace_binder_unmap_kernel_start(alloc, index);
