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From:   Lee Jones <lee.jones@linaro.org>
To:     lee.jones@linaro.org
Cc:     linux-kernel@vger.kernel.org,
        Felix Kuehling <Felix.Kuehling@amd.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>, amd-gfx@lists.freedesktop.org,
        dri-devel@lists.freedesktop.org
Subject: [PATCH 1/1] drm/amdkfd: Protect the Client whilst it is being operated on
Date:   Thu, 17 Mar 2022 13:16:10 +0000
Message-Id: <20220317131610.554347-1-lee.jones@linaro.org>
MIME-Version: 1.0
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Precedence: bulk

Presently the Client can be freed whilst still in use.

Use the already provided lock to prevent this.

Cc: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
 drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c
index e4beebb1c80a2..3b9ac1e87231f 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c
@@ -145,8 +145,11 @@ static int kfd_smi_ev_release(struct inode *inode, struct file *filep)
 	spin_unlock(&dev->smi_lock);
 
 	synchronize_rcu();
+
+	spin_lock(&client->lock);
 	kfifo_free(&client->fifo);
 	kfree(client);
+	spin_unlock(&client->lock);
 
 	return 0;
 }
@@ -247,11 +250,13 @@ int kfd_smi_event_open(struct kfd_dev *dev, uint32_t *fd)
 		return ret;
 	}
 
+	spin_lock(&client->lock);
 	ret = anon_inode_getfd(kfd_smi_name, &kfd_smi_ev_fops, (void *)client,
 			       O_RDWR);
 	if (ret < 0) {
 		kfifo_free(&client->fifo);
 		kfree(client);
+		spin_unlock(&client->lock);
 		return ret;
 	}
 	*fd = ret;
@@ -264,6 +269,7 @@ int kfd_smi_event_open(struct kfd_dev *dev, uint32_t *fd)
 	spin_lock(&dev->smi_lock);
 	list_add_rcu(&client->list, &dev->smi_clients);
 	spin_unlock(&dev->smi_lock);
+	spin_unlock(&client->lock);
 
 	return 0;
 }
-- 
2.35.1.894.gb6a874cedc-goog