vma_close frees qfrs but not clears q->qfrs, which still points to the freed object, leading to subsequent mmap fail. So vma_close clears q->qfrs as well.
Suggested-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Zhangfei Gao zhangfei.gao@linaro.org --- drivers/misc/uacce/uacce.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c index 338b59ef5493..930c252753a0 100644 --- a/drivers/misc/uacce/uacce.c +++ b/drivers/misc/uacce/uacce.c @@ -200,12 +200,15 @@ static int uacce_fops_release(struct inode *inode, struct file *filep) static void uacce_vma_close(struct vm_area_struct *vma) { struct uacce_queue *q = vma->vm_private_data; - struct uacce_qfile_region *qfr = NULL;
- if (vma->vm_pgoff < UACCE_MAX_REGION) - qfr = q->qfrs[vma->vm_pgoff]; + if (vma->vm_pgoff < UACCE_MAX_REGION) { + struct uacce_qfile_region *qfr = q->qfrs[vma->vm_pgoff];
- kfree(qfr); + mutex_lock(&q->mutex); + q->qfrs[vma->vm_pgoff] = NULL; + mutex_unlock(&q->mutex); + kfree(qfr); + } }
static const struct vm_operations_struct uacce_vm_ops = {