tee: shm: fix use-after-free via temporarily dropped reference

[linux-2.6-microblaze.git] / drivers / tee / tee_shm.c

diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 556960a..07d3be6 100644 (file)
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -360,9 +360,10 @@ int tee_shm_get_fd(struct tee_shm *shm)
        if (!(shm->flags & TEE_SHM_DMA_BUF))
                return -EINVAL;
 
+       get_dma_buf(shm->dmabuf);
        fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
-       if (fd >= 0)
-               get_dma_buf(shm->dmabuf);
+       if (fd < 0)
+               dma_buf_put(shm->dmabuf);
        return fd;
 }