FAILED: patch "[PATCH] drm/amdgpu: fix memory leak in" failed to apply to 4.2-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 4.2-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 7a574557e62dc3d2d7ed55fa0b99e7d5bb403878 Mon Sep 17 00:00:00 2001
From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Date: Thu, 8 Oct 2015 19:28:01 +0530
Subject: [PATCH] drm/amdgpu: fix memory leak in
 amdgpu_vm_update_page_directory
MIME-Version: 1.0
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If amdgpu_ib_get() fails we returned the error code but we missed
freeing ib.

Cc: "Christian König" <christian.koenig@amd.com>
Cc: Jammy Zhou <Jammy.Zhou@amd.com>
Cc: Chunming Zhou <david1.zhou@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "monk.liu" <monk.liu@amd.com>
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 1e14531353e0..53d551f2d839 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -455,8 +455,10 @@ int amdgpu_vm_update_page_directory(struct amdgpu_device *adev,
 		return -ENOMEM;
 
 	r = amdgpu_ib_get(ring, NULL, ndw * 4, ib);
-	if (r)
+	if (r) {
+		kfree(ib);
 		return r;
+	}
 	ib->length_dw = 0;
 
 	/* walk over the address space and update the page directory */