Supply additional checks in order to prevent unexpected results.

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 --- Destined for v4.4.y and v4.9.y

drivers/staging/android/ion/ion.c | 6 ++++++ 1 file changed, 6 insertions(+)

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 806e9b30b9dc8..aac9b38b8c25c 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -489,6 +489,9 @@ static void *ion_buffer_kmap_get(struct ion_buffer *buffer) void *vaddr;

if (buffer->kmap_cnt) { + if (buffer->kmap_cnt == INT_MAX) + return ERR_PTR(-EOVERFLOW); + buffer->kmap_cnt++; return buffer->vaddr; } @@ -509,6 +512,9 @@ static void *ion_handle_kmap_get(struct ion_handle *handle) void *vaddr;

if (handle->kmap_cnt) { + if (handle->kmap_cnt == INT_MAX) + return ERR_PTR(-EOVERFLOW); + handle->kmap_cnt++; return buffer->vaddr; }