Re: [PATCH] drm/amdkfd: Fix file reference leak in criu_restore_devices()

[kernel test robot <lkp@intel.com>]

Hi Wentao,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on linus/master v7.3-rc3 next-20260916]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Wentao-Liang/drm-amdkfd-Fix-file-reference-leak-in-criu_restore_devices/20260916-074216
base:   https://gitlab.freedesktop.org/drm/misc/kernel.git drm-misc-next
patch link:    https://lore.kernel.org/r/20260916074216.1973191-1-vulab%40iscas.ac.cn
patch subject: [PATCH] drm/amdkfd: Fix file reference leak in criu_restore_devices()
config: x86_64-randconfig-1300-20260917 (https://download.01.org/0day-ci/archive/20260917/202609171036.aewbdced-lkp@intel.com/config)
compiler: clang version 22.1.3 (https://github.com/llvm/llvm-project e9846648fd6183ee6d8cbdb4502213fcf902a211)
sparse: v0.6.5-rc1
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260917/202609171036.aewbdced-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202609171036.aewbdced-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_chardev.c:2383:9: warning: variable 'drm_file' is uninitialized when used here [-Wuninitialized]
    2383 |                         fput(drm_file);
         |                              ^~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_chardev.c:2356:24: note: initialize the variable 'drm_file' to silence this warning
    2356 |                 struct file *drm_file;
         |                                      ^
         |                                       = NULL
   1 warning generated.


vim +/drm_file +2383 drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_chardev.c

  2330	
  2331	static int criu_restore_devices(struct kfd_process *p,
  2332					struct kfd_ioctl_criu_args *args,
  2333					uint64_t *priv_offset,
  2334					uint64_t max_priv_data_size)
  2335	{
  2336		struct kfd_criu_device_bucket *device_buckets;
  2337		struct kfd_criu_device_priv_data *device_privs;
  2338		int ret = 0;
  2339		uint32_t i;
  2340	
  2341		if (args->num_devices != p->n_pdds)
  2342			return -EINVAL;
  2343	
  2344		if (*priv_offset + (args->num_devices * sizeof(*device_privs)) > max_priv_data_size)
  2345			return -EINVAL;
  2346	
  2347		device_buckets = memdup_array_user((void *)args->devices,
  2348						args->num_devices, sizeof(*device_buckets));
  2349	
  2350		if (IS_ERR(device_buckets))
  2351			return PTR_ERR(device_buckets);
  2352	
  2353		for (i = 0; i < args->num_devices; i++) {
  2354			struct kfd_node *dev;
  2355			struct kfd_process_device *pdd;
  2356			struct file *drm_file;
  2357	
  2358			/* device private data is not currently used */
  2359	
  2360			if (!device_buckets[i].user_gpu_id) {
  2361				pr_err("Invalid user gpu_id\n");
  2362				ret = -EINVAL;
  2363				goto exit;
  2364			}
  2365	
  2366			dev = kfd_device_by_id(device_buckets[i].actual_gpu_id);
  2367			if (!dev) {
  2368				pr_err("Failed to find device with gpu_id = %x\n",
  2369					device_buckets[i].actual_gpu_id);
  2370				ret = -EINVAL;
  2371				goto exit;
  2372			}
  2373	
  2374			pdd = kfd_get_process_device_data(dev, p);
  2375			if (!pdd) {
  2376				pr_err("Failed to get pdd for gpu_id = %x\n",
  2377						device_buckets[i].actual_gpu_id);
  2378				ret = -EINVAL;
  2379				goto exit;
  2380			}
  2381	
  2382			if (pdd->drm_file) {
> 2383				fput(drm_file);
  2384				ret = -EINVAL;
  2385				goto exit;
  2386			}
  2387			pdd->user_gpu_id = device_buckets[i].user_gpu_id;
  2388	
  2389			drm_file = fget(device_buckets[i].drm_fd);
  2390			if (!drm_file) {
  2391				pr_err("Invalid render node file descriptor sent from plugin (%d)\n",
  2392					device_buckets[i].drm_fd);
  2393				ret = -EINVAL;
  2394				goto exit;
  2395			}
  2396	
  2397			/* create the vm using render nodes for kfd pdd */
  2398			if (kfd_process_device_init_vm(pdd, drm_file)) {
  2399				pr_err("could not init vm for given pdd\n");
  2400				/* On success, the PDD keeps the drm_file reference */
  2401				fput(drm_file);
  2402				ret = -EINVAL;
  2403				goto exit;
  2404			}
  2405			/*
  2406			 * pdd now already has the vm bound to render node so below api won't create a new
  2407			 * exclusive kfd mapping but use existing one with renderDXXX but is still needed
  2408			 * for iommu v2 binding  and runtime pm.
  2409			 */
  2410			pdd = kfd_bind_process_to_device(dev, p);
  2411			if (IS_ERR(pdd)) {
  2412				ret = PTR_ERR(pdd);
  2413				goto exit;
  2414			}
  2415	
  2416			if (!pdd->qpd.proc_doorbells) {
  2417				ret = kfd_alloc_process_doorbells(dev->kfd, pdd);
  2418				if (ret)
  2419					goto exit;
  2420			}
  2421		}
  2422	
  2423		/*
  2424		 * We are not copying device private data from user as we are not using the data for now,
  2425		 * but we still adjust for its private data.
  2426		 */
  2427		*priv_offset += args->num_devices * sizeof(*device_privs);
  2428	
  2429	exit:
  2430		kfree(device_buckets);
  2431		return ret;
  2432	}
  2433	

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