BACKPORT: staging: ion: Prevent incorrect reference counting behavour
Supply additional check in order to prevent unexpected results.
Bug: 205573273
Fixes: b892bf75b2034 ("ion: Switch ion to use dma-buf")
Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[Lee: Patch now applies to ion_buffer.c instead of ion.c]
Change-Id: Ia6afdd9ca502caa9cad6619d438fc6c8e8457679
(cherry picked from commit 27da8d16e4f0a0ef37da356599eb36adec542643)
diff --git a/drivers/staging/android/ion/ion_buffer.c b/drivers/staging/android/ion/ion_buffer.c
index e22330f..9dfb94e 100644
--- a/drivers/staging/android/ion/ion_buffer.c
+++ b/drivers/staging/android/ion/ion_buffer.c
@@ -249,6 +249,9 @@
void *vaddr;
if (buffer->kmap_cnt) {
+ if (buffer->kmap_cnt == INT_MAX)
+ return ERR_PTR(-EOVERFLOW);
+
buffer->kmap_cnt++;
return buffer->vaddr;
}
