[PATCH 02/12] drm/v3d: Fix potential memory leak in the timestamp extension

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>

If fetching of userspace memory fails during the main loop, all drm sync
objs looked up until that point will be leaked because of the missing
drm_syncobj_put.

Fix it by exporting and using a common cleanup helper.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at igalia.com>
Fixes: 9ba0ff3e083f ("drm/v3d: Create a CPU job extension for the timestamp query job")
Cc: Maíra Canal <mcanal at igalia.com>
Cc: Iago Toral Quiroga <itoral at igalia.com>
Cc: <stable at vger.kernel.org> # v6.8+
---
 drivers/gpu/drm/v3d/v3d_drv.h    |  2 ++
 drivers/gpu/drm/v3d/v3d_sched.c  | 22 +++++++++++++------
 drivers/gpu/drm/v3d/v3d_submit.c | 36 ++++++++++++++++++++++----------
 3 files changed, 43 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
index 099b962bdfde..95651c3c926f 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.h
+++ b/drivers/gpu/drm/v3d/v3d_drv.h
@@ -563,6 +563,8 @@ void v3d_mmu_insert_ptes(struct v3d_bo *bo);
 void v3d_mmu_remove_ptes(struct v3d_bo *bo);
 
 /* v3d_sched.c */
+void __v3d_timestamp_query_info_free(struct v3d_timestamp_query_info *qinfo,
+				     unsigned int count);
 void v3d_job_update_stats(struct v3d_job *job, enum v3d_queue queue);
 int v3d_sched_init(struct v3d_dev *v3d);
 void v3d_sched_fini(struct v3d_dev *v3d);
diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c
index 03df37a3acf5..e45d3ddc6f82 100644
--- a/drivers/gpu/drm/v3d/v3d_sched.c
+++ b/drivers/gpu/drm/v3d/v3d_sched.c
@@ -73,18 +73,28 @@ v3d_sched_job_free(struct drm_sched_job *sched_job)
 	v3d_job_cleanup(job);
 }
 
+void
+__v3d_timestamp_query_info_free(struct v3d_timestamp_query_info *qinfo,
+				unsigned int count)
+{
+	if (qinfo->queries) {
+		unsigned int i;
+
+		for (i = 0; i < count; i++)
+			drm_syncobj_put(qinfo->queries[i].syncobj);
+
+		kvfree(qinfo->queries);
+	}
+}
+
 static void
 v3d_cpu_job_free(struct drm_sched_job *sched_job)
 {
 	struct v3d_cpu_job *job = to_cpu_job(sched_job);
-	struct v3d_timestamp_query_info *timestamp_query = &job->timestamp_query;
 	struct v3d_performance_query_info *performance_query = &job->performance_query;
 
-	if (timestamp_query->queries) {
-		for (int i = 0; i < timestamp_query->count; i++)
-			drm_syncobj_put(timestamp_query->queries[i].syncobj);
-		kvfree(timestamp_query->queries);
-	}
+	__v3d_timestamp_query_info_free(&job->timestamp_query,
+					job->timestamp_query.count);
 
 	if (performance_query->queries) {
 		for (int i = 0; i < performance_query->count; i++)
diff --git a/drivers/gpu/drm/v3d/v3d_submit.c b/drivers/gpu/drm/v3d/v3d_submit.c
index 263fefc1d04f..2818afdd4807 100644
--- a/drivers/gpu/drm/v3d/v3d_submit.c
+++ b/drivers/gpu/drm/v3d/v3d_submit.c
@@ -452,6 +452,7 @@ v3d_get_cpu_timestamp_query_params(struct drm_file *file_priv,
 {
 	u32 __user *offsets, *syncs;
 	struct drm_v3d_timestamp_query timestamp;
+	int err;
 
 	if (!job) {
 		DRM_DEBUG("CPU job extension was attached to a GPU job.\n");
@@ -484,15 +485,15 @@ v3d_get_cpu_timestamp_query_params(struct drm_file *file_priv,
 		u32 offset, sync;
 
 		if (copy_from_user(&offset, offsets++, sizeof(offset))) {
-			kvfree(job->timestamp_query.queries);
-			return -EFAULT;
+			err = -EFAULT;
+			goto error;
 		}
 
 		job->timestamp_query.queries[i].offset = offset;
 
 		if (copy_from_user(&sync, syncs++, sizeof(sync))) {
-			kvfree(job->timestamp_query.queries);
-			return -EFAULT;
+			err = -EFAULT;
+			goto error;
 		}
 
 		job->timestamp_query.queries[i].syncobj = drm_syncobj_find(file_priv, sync);
@@ -500,6 +501,10 @@ v3d_get_cpu_timestamp_query_params(struct drm_file *file_priv,
 	job->timestamp_query.count = timestamp.count;
 
 	return 0;
+
+error:
+	__v3d_timestamp_query_info_free(qinfo, i);
+	return err;
 }
 
 static int
@@ -509,6 +514,7 @@ v3d_get_cpu_reset_timestamp_params(struct drm_file *file_priv,
 {
 	u32 __user *syncs;
 	struct drm_v3d_reset_timestamp_query reset;
+	int err;
 
 	if (!job) {
 		DRM_DEBUG("CPU job extension was attached to a GPU job.\n");
@@ -539,8 +545,8 @@ v3d_get_cpu_reset_timestamp_params(struct drm_file *file_priv,
 		job->timestamp_query.queries[i].offset = reset.offset + 8 * i;
 
 		if (copy_from_user(&sync, syncs++, sizeof(sync))) {
-			kvfree(job->timestamp_query.queries);
-			return -EFAULT;
+			err = -EFAULT;
+			goto error;
 		}
 
 		job->timestamp_query.queries[i].syncobj = drm_syncobj_find(file_priv, sync);
@@ -548,6 +554,10 @@ v3d_get_cpu_reset_timestamp_params(struct drm_file *file_priv,
 	job->timestamp_query.count = reset.count;
 
 	return 0;
+
+error:
+	__v3d_timestamp_query_info_free(qinfo, i);
+	return err;
 }
 
 /* Get data for the copy timestamp query results job submission. */
@@ -558,7 +568,7 @@ v3d_get_cpu_copy_query_results_params(struct drm_file *file_priv,
 {
 	u32 __user *offsets, *syncs;
 	struct drm_v3d_copy_timestamp_query copy;
-	int i;
+	int i, err;
 
 	if (!job) {
 		DRM_DEBUG("CPU job extension was attached to a GPU job.\n");
@@ -591,15 +601,15 @@ v3d_get_cpu_copy_query_results_params(struct drm_file *file_priv,
 		u32 offset, sync;
 
 		if (copy_from_user(&offset, offsets++, sizeof(offset))) {
-			kvfree(job->timestamp_query.queries);
-			return -EFAULT;
+			err = -EFAULT;
+			goto error;
 		}
 
 		job->timestamp_query.queries[i].offset = offset;
 
 		if (copy_from_user(&sync, syncs++, sizeof(sync))) {
-			kvfree(job->timestamp_query.queries);
-			return -EFAULT;
+			err = -EFAULT;
+			goto error;
 		}
 
 		job->timestamp_query.queries[i].syncobj = drm_syncobj_find(file_priv, sync);
@@ -613,6 +623,10 @@ v3d_get_cpu_copy_query_results_params(struct drm_file *file_priv,
 	job->copy.stride = copy.stride;
 
 	return 0;
+
+error:
+	__v3d_timestamp_query_info_free(qinfo, i);
+	return err;
 }
 
 static int
-- 
2.44.0