habanalabs: Avoid double free in error flow
authorTomer Tayar <ttayar@habana.ai>
Thu, 1 Aug 2019 13:57:36 +0000 (13:57 +0000)
committerOded Gabbay <oded.gabbay@gmail.com>
Mon, 12 Aug 2019 06:00:34 +0000 (09:00 +0300)
In case kernel context init fails during device initialization, both
hl_ctx_put() and kfree() are called, ending with a double free of the
kernel context.
Calling kfree() is needed only when a failure happens between the
allocation of the kernel context and its initialization, so move it to
there and remove it from the error flow.

Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
drivers/misc/habanalabs/device.c

index 0c4894d..7a8f9d0 100644 (file)
@@ -970,7 +970,8 @@ int hl_device_init(struct hl_device *hdev, struct class *hclass)
        rc = hl_ctx_init(hdev, hdev->kernel_ctx, true);
        if (rc) {
                dev_err(hdev->dev, "failed to initialize kernel context\n");
-               goto free_ctx;
+               kfree(hdev->kernel_ctx);
+               goto mmu_fini;
        }
 
        rc = hl_cb_pool_init(hdev);
@@ -1053,8 +1054,6 @@ release_ctx:
        if (hl_ctx_put(hdev->kernel_ctx) != 1)
                dev_err(hdev->dev,
                        "kernel ctx is still alive on initialization failure\n");
-free_ctx:
-       kfree(hdev->kernel_ctx);
 mmu_fini:
        hl_mmu_fini(hdev);
 eq_fini: