[PATCH 1/1] staging: ion: Prevent incorrect reference counting behavour

Supply additional checks in order to prevent unexpected results.

Fixes: b892bf75b2034 ("ion: Switch ion to use dma-buf") Signed-off-by: Lee Jones lee.jones@linaro.org --- drivers/staging/android/ion/ion.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 806e9b30b9dc8..30f359faba575 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -509,6 +509,9 @@ static void *ion_handle_kmap_get(struct ion_handle *handle) void *vaddr;

if (handle->kmap_cnt) { + if (handle->kmap_cnt + 1 < handle->kmap_cnt) + return ERR_PTR(-EOVERFLOW); + handle->kmap_cnt++; return buffer->vaddr; }