drm/v3d: Fix potential memory leak in the timestamp 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 <[email protected]>
Fixes: 9ba0ff3e083f ("drm/v3d: Create a CPU job extension for the timestamp query job")
Cc: Maíra Canal <[email protected]>
Cc: Iago Toral Quiroga <[email protected]>
Cc: [email protected] # v6.8+
Reviewed-by: Maíra Canal <[email protected]>
Signed-off-by: Maíra Canal <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
(cherry picked from commit 753ce4fea62182c77e1691ab4f9022008f25b62e)
Signed-off-by: Thomas Zimmermann <[email protected]>

3 files changed, 48 insertions, 19 deletions

diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
index a2c516fe6d79..c46eed35d26b 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.h
+++ b/drivers/gpu/drm/v3d/v3d_drv.h
@@ -556,6 +556,8 @@ 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 *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);
diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c
index 7cd8c335cd9b..3da4fa49552b 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 *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_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..121bf1314b80 100644
--- a/drivers/gpu/drm/v3d/v3d_submit.c
+++ b/drivers/gpu/drm/v3d/v3d_submit.c
@@ -452,6 +452,8 @@ v3d_get_cpu_timestamp_query_params(struct drm_file *file_priv,
 {
 	u32 __user *offsets, *syncs;
 	struct drm_v3d_timestamp_query timestamp;
+	unsigned int i;
+	int err;
 
 	if (!job) {
 		DRM_DEBUG("CPU job extension was attached to a GPU job.\n");
@@ -480,19 +482,19 @@ v3d_get_cpu_timestamp_query_params(struct drm_file *file_priv,
 	offsets = u64_to_user_ptr(timestamp.offsets);
 	syncs = u64_to_user_ptr(timestamp.syncs);
 
-	for (int i = 0; i < timestamp.count; i++) {
+	for (i = 0; i < timestamp.count; i++) {
 		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 +502,10 @@ 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(&job->timestamp_query, i);
+	return err;
 }
 
 static int
@@ -509,6 +515,8 @@ v3d_get_cpu_reset_timestamp_params(struct drm_file *file_priv,
 {
 	u32 __user *syncs;
 	struct drm_v3d_reset_timestamp_query reset;
+	unsigned int i;
+	int err;
 
 	if (!job) {
 		DRM_DEBUG("CPU job extension was attached to a GPU job.\n");
@@ -533,14 +541,14 @@ v3d_get_cpu_reset_timestamp_params(struct drm_file *file_priv,
 
 	syncs = u64_to_user_ptr(reset.syncs);
 
-	for (int i = 0; i < reset.count; i++) {
+	for (i = 0; i < reset.count; i++) {
 		u32 sync;
 
 		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 +556,10 @@ 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(&job->timestamp_query, i);
+	return err;
 }
 
 /* Get data for the copy timestamp query results job submission. */
@@ -558,7 +570,8 @@ 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;
+	unsigned int i;
+	int err;
 
 	if (!job) {
 		DRM_DEBUG("CPU job extension was attached to a GPU job.\n");
@@ -591,15 +604,15 @@ 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 +626,10 @@ 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(&job->timestamp_query, i);
+	return err;
 }
 
 static int