[PATCH] drm/amd: fix potential memleak in err branch

From: Bernard Zhao <bernard@vivo.com>
To: "Felix Kuehling" <Felix.Kuehling@amd.com>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"David Airlie" <airlied@linux.ie>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Cc: opensource.kernel@vivo.com, Bernard Zhao <bernard@vivo.com>
Subject: [PATCH] drm/amd: fix potential memleak in err branch
Date: Fri, 19 Jun 2020 19:45:33 +0800	[thread overview]
Message-ID: <20200619114533.2612-1-bernard@vivo.com> (raw)

The function kobject_init_and_add alloc memory like:
kobject_init_and_add->kobject_add_varg->kobject_set_name_vargs
->kvasprintf_const->kstrdup_const->kstrdup->kmalloc_track_caller
->kmalloc_slab, in err branch this memory not free. If use
kmemleak, this path maybe catched.
These changes are to add kobject_put in kobject_init_and_add
failed branch, fix potential memleak.

Signed-off-by: Bernard Zhao <bernard@vivo.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_process.c  |  2 ++
 drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 20 +++++++++++++++-----
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index d27221ddcdeb..5ee4d6cfb16d 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -124,6 +124,7 @@ void kfd_procfs_init(void)
 	if (ret) {
 		pr_warn("Could not create procfs proc folder");
 		/* If we fail to create the procfs, clean up */
+		kobject_put(procfs.kobj);
 		kfd_procfs_shutdown();
 	}
 }
@@ -428,6 +429,7 @@ struct kfd_process *kfd_create_process(struct file *filep)
 					   (int)process->lead_thread->pid);
 		if (ret) {
 			pr_warn("Creating procfs pid directory failed");
+			kobject_put(process->kobj);
 			goto out;
 		}
 
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
index bb77f7af2b6d..dc3c4149f860 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
@@ -632,8 +632,10 @@ static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 
 	ret = kobject_init_and_add(dev->kobj_node, &node_type,
 			sys_props.kobj_nodes, "%d", id);
-	if (ret < 0)
+	if (ret < 0) {
+		kobject_put(dev->kobj_node);
 		return ret;
+	}
 
 	dev->kobj_mem = kobject_create_and_add("mem_banks", dev->kobj_node);
 	if (!dev->kobj_mem)
@@ -680,8 +682,10 @@ static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 			return -ENOMEM;
 		ret = kobject_init_and_add(mem->kobj, &mem_type,
 				dev->kobj_mem, "%d", i);
-		if (ret < 0)
+		if (ret < 0) {
+			kobject_put(mem->kobj);
 			return ret;
+		}
 
 		mem->attr.name = "properties";
 		mem->attr.mode = KFD_SYSFS_FILE_MODE;
@@ -699,8 +703,10 @@ static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 			return -ENOMEM;
 		ret = kobject_init_and_add(cache->kobj, &cache_type,
 				dev->kobj_cache, "%d", i);
-		if (ret < 0)
+		if (ret < 0) {
+			kobject_put(cache->kobj);
 			return ret;
+		}
 
 		cache->attr.name = "properties";
 		cache->attr.mode = KFD_SYSFS_FILE_MODE;
@@ -718,8 +724,10 @@ static int kfd_build_sysfs_node_entry(struct kfd_topology_device *dev,
 			return -ENOMEM;
 		ret = kobject_init_and_add(iolink->kobj, &iolink_type,
 				dev->kobj_iolink, "%d", i);
-		if (ret < 0)
+		if (ret < 0) {
+			kobject_put(iolink->kobj);
 			return ret;
+		}
 
 		iolink->attr.name = "properties";
 		iolink->attr.mode = KFD_SYSFS_FILE_MODE;
@@ -798,8 +806,10 @@ static int kfd_topology_update_sysfs(void)
 		ret = kobject_init_and_add(sys_props.kobj_topology,
 				&sysprops_type,  &kfd_device->kobj,
 				"topology");
-		if (ret < 0)
+		if (ret < 0) {
+			kobject_put(sys_props.kobj_topology);
 			return ret;
+		}
 
 		sys_props.kobj_nodes = kobject_create_and_add("nodes",
 				sys_props.kobj_topology);
-- 
2.17.1

