* Re: [PATCH] iommu/exynos: fix NULL pointer dereference on device_link_add() failure
[not found] <20261009034539.3073100-1-vulab@iscas.ac.cn>
@ 2026-10-09 16:42 ` kernel test robot
0 siblings, 0 replies; only message in thread
From: kernel test robot @ 2026-10-09 16:42 UTC (permalink / raw)
To: Haotian Zhang, Marek Szyprowski, Will Deacon, Robin Murphy,
Krzysztof Kozlowski, Peter Griffin, Alim Akhtar, Joerg Roedel
Cc: llvm, oe-kbuild-all, iommu, linux-arm-kernel, linux-samsung-soc,
linux-kernel
Hi Haotian,
kernel test robot noticed the following build warnings:
[auto build test WARNING on krzk/for-next]
[also build test WARNING on arm-perf/for-next/perf pinctrl-samsung/for-next linus/master v7.3-rc6 next-20261008]
[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/Haotian-Zhang/iommu-exynos-fix-NULL-pointer-dereference-on-device_link_add-failure/20261009-114539
base: https://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux.git for-next
patch link: https://lore.kernel.org/r/20261009034539.3073100-1-vulab%40iscas.ac.cn
patch subject: [PATCH] iommu/exynos: fix NULL pointer dereference on device_link_add() failure
config: arm-defconfig (https://download.01.org/0day-ci/archive/20261010/202610100049.FvaUUeCb-lkp@intel.com/config)
compiler: clang version 24.0.0git (https://github.com/llvm/llvm-project 242243a5814307de825db3428662d67b064e2cbc)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261010/202610100049.FvaUUeCb-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/202610100049.FvaUUeCb-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> drivers/iommu/exynos-iommu.c:1434:39: warning: variable 'tmp' is uninitialized when used here [-Wuninitialized]
1434 | list_for_each_entry_continue_reverse(tmp, &owner->controllers,
| ^~~
drivers/iommu/exynos-iommu.c:1406:35: note: initialize the variable 'tmp' to silence this warning
1406 | struct sysmmu_drvdata *data, *tmp;
| ^
| = NULL
1 warning generated.
vim +/tmp +1434 drivers/iommu/exynos-iommu.c
1402
1403 static struct iommu_device *exynos_iommu_probe_device(struct device *dev)
1404 {
1405 struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
1406 struct sysmmu_drvdata *data, *tmp;
1407
1408 if (!has_sysmmu(dev))
1409 return ERR_PTR(-ENODEV);
1410
1411 list_for_each_entry(data, &owner->controllers, owner_node) {
1412 /*
1413 * SYSMMU will be runtime activated via device link
1414 * (dependency) to its master device, so there are no
1415 * direct calls to pm_runtime_get/put in this driver.
1416 */
1417 data->link = device_link_add(dev, data->sysmmu,
1418 DL_FLAG_STATELESS |
1419 DL_FLAG_PM_RUNTIME);
1420 if (!data->link) {
1421 dev_err(dev, "Unable to link %s\n",
1422 dev_name(data->sysmmu));
1423 goto err_unlink;
1424 }
1425 }
1426
1427 /* There is always at least one entry, see exynos_iommu_of_xlate() */
1428 data = list_first_entry(&owner->controllers,
1429 struct sysmmu_drvdata, owner_node);
1430
1431 return &data->iommu;
1432
1433 err_unlink:
> 1434 list_for_each_entry_continue_reverse(tmp, &owner->controllers,
1435 owner_node)
1436 device_link_del(tmp->link);
1437
1438 return ERR_PTR(-ENODEV);
1439 }
1440
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
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