drm/v3d: Fix potential memory leak in the performance extension

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@igalia.com>
Fixes: bae7cb5 ("drm/v3d: Create a CPU job extension for the reset performance query job")
Cc: Maíra Canal <mcanal@igalia.com>
Cc: Iago Toral Quiroga <itoral@igalia.com>
Cc: stable@vger.kernel.org # v6.8+
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240711135340.84617-4-tursulin@igalia.com
(cherry picked from commit 484de39)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Author: Tvrtko Ursulin

drivers/gpu/drm/v3d/v3d_drv.h

@@ -558,6 +558,8 @@ void v3d_mmu_remove_ptes(struct v3d_bo *bo);
 /* v3d_sched.c */
 void v3d_timestamp_query_info_free(struct v3d_timestamp_query_info *query_info,
 				   unsigned int count);
+void v3d_performance_query_info_free(struct v3d_performance_query_info *query_info,
+				     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);

drivers/gpu/drm/v3d/v3d_sched.c

@@ -87,20 +87,30 @@ v3d_timestamp_query_info_free(struct v3d_timestamp_query_info *query_info,
 	}
 }
 
+void
+v3d_performance_query_info_free(struct v3d_performance_query_info *query_info,
+				unsigned int count)
+{
+	if (query_info->queries) {
+		unsigned int i;
+
+		for (i = 0; i < count; i++)
+			drm_syncobj_put(query_info->queries[i].syncobj);
+
+		kvfree(query_info->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_performance_query_info *performance_query = &job->performance_query;
 
 	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++)
-			drm_syncobj_put(performance_query->queries[i].syncobj);
-		kvfree(performance_query->queries);
-	}
+	v3d_performance_query_info_free(&job->performance_query,
+					job->performance_query.count);
 
 	v3d_job_cleanup(&job->base);
 }

drivers/gpu/drm/v3d/v3d_submit.c

@@ -640,6 +640,8 @@ v3d_get_cpu_reset_performance_params(struct drm_file *file_priv,
 	u32 __user *syncs;
 	u64 __user *kperfmon_ids;
 	struct drm_v3d_reset_performance_query reset;
+	unsigned int i, j;
+	int err;
 
 	if (!job) {
 		DRM_DEBUG("CPU job extension was attached to a GPU job.\n");
@@ -668,39 +670,43 @@ v3d_get_cpu_reset_performance_params(struct drm_file *file_priv,
 	syncs = u64_to_user_ptr(reset.syncs);
 	kperfmon_ids = u64_to_user_ptr(reset.kperfmon_ids);
 
-	for (int i = 0; i < reset.count; i++) {
+	for (i = 0; i < reset.count; i++) {
 		u32 sync;
 		u64 ids;
 		u32 __user *ids_pointer;
 		u32 id;
 
 		if (copy_from_user(&sync, syncs++, sizeof(sync))) {
-			kvfree(job->performance_query.queries);
-			return -EFAULT;
+			err = -EFAULT;
+			goto error;
 		}
 
-		job->performance_query.queries[i].syncobj = drm_syncobj_find(file_priv, sync);
-
 		if (copy_from_user(&ids, kperfmon_ids++, sizeof(ids))) {
-			kvfree(job->performance_query.queries);
-			return -EFAULT;
+			err = -EFAULT;
+			goto error;
 		}
 
 		ids_pointer = u64_to_user_ptr(ids);
 
-		for (int j = 0; j < reset.nperfmons; j++) {
+		for (j = 0; j < reset.nperfmons; j++) {
 			if (copy_from_user(&id, ids_pointer++, sizeof(id))) {
-				kvfree(job->performance_query.queries);
-				return -EFAULT;
+				err = -EFAULT;
+				goto error;
 			}
 
 			job->performance_query.queries[i].kperfmon_ids[j] = id;
 		}
+
+		job->performance_query.queries[i].syncobj = drm_syncobj_find(file_priv, sync);
 	}
 	job->performance_query.count = reset.count;
 	job->performance_query.nperfmons = reset.nperfmons;
 
 	return 0;
+
+error:
+	v3d_performance_query_info_free(&job->performance_query, i);
+	return err;
 }
 
 static int
@@ -711,6 +717,8 @@ v3d_get_cpu_copy_performance_query_params(struct drm_file *file_priv,
 	u32 __user *syncs;
 	u64 __user *kperfmon_ids;
 	struct drm_v3d_copy_performance_query copy;
+	unsigned int i, j;
+	int err;
 
 	if (!job) {
 		DRM_DEBUG("CPU job extension was attached to a GPU job.\n");
@@ -742,34 +750,34 @@ v3d_get_cpu_copy_performance_query_params(struct drm_file *file_priv,
 	syncs = u64_to_user_ptr(copy.syncs);
 	kperfmon_ids = u64_to_user_ptr(copy.kperfmon_ids);
 
-	for (int i = 0; i < copy.count; i++) {
+	for (i = 0; i < copy.count; i++) {
 		u32 sync;
 		u64 ids;
 		u32 __user *ids_pointer;
 		u32 id;
 
 		if (copy_from_user(&sync, syncs++, sizeof(sync))) {
-			kvfree(job->performance_query.queries);
-			return -EFAULT;
+			err = -EFAULT;
+			goto error;
 		}
 
-		job->performance_query.queries[i].syncobj = drm_syncobj_find(file_priv, sync);
-
 		if (copy_from_user(&ids, kperfmon_ids++, sizeof(ids))) {
-			kvfree(job->performance_query.queries);
-			return -EFAULT;
+			err = -EFAULT;
+			goto error;
 		}
 
 		ids_pointer = u64_to_user_ptr(ids);
 
-		for (int j = 0; j < copy.nperfmons; j++) {
+		for (j = 0; j < copy.nperfmons; j++) {
 			if (copy_from_user(&id, ids_pointer++, sizeof(id))) {
-				kvfree(job->performance_query.queries);
-				return -EFAULT;
+				err = -EFAULT;
+				goto error;
 			}
 
 			job->performance_query.queries[i].kperfmon_ids[j] = id;
 		}
+
+		job->performance_query.queries[i].syncobj = drm_syncobj_find(file_priv, sync);
 	}
 	job->performance_query.count = copy.count;
 	job->performance_query.nperfmons = copy.nperfmons;
@@ -782,6 +790,10 @@ v3d_get_cpu_copy_performance_query_params(struct drm_file *file_priv,
 	job->copy.stride = copy.stride;
 
 	return 0;
+
+error:
+	v3d_performance_query_info_free(&job->performance_query, i);
+	return err;
 }
 
 /* Whenever userspace sets ioctl extensions, v3d_get_extensions parses data