uacce: vma_close clears q->qfrs when freeing qfrs

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>
Link: https://lore.kernel.org/r/20230511095921.9331-3-zhangfei.gao@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
index 338b59ef5493dfc7648c058175f86c61a0b56940..930c252753a073ac13b8a8d09899f60d37c46b47 100644 (file)
--- 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 = {