[PATCH 4.19 43/53] staging: ion: Prevent incorrect reference counting behavour

Supply additional check 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/staging/android/ion/ion.c | 3 +++ 1 file changed, 3 insertions(+)

--- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -140,6 +140,9 @@ static void *ion_buffer_kmap_get(struct void *vaddr;

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