linux-kernel - [PATCH] selftests/iommu: prevent use of uninitialized variable

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250923150108.34309-1-alessandro.zanni87@gmail.com>
Date: Tue, 23 Sep 2025 17:01:06 +0200
From: Alessandro Zanni <alessandro.zanni87@...il.com>
To: jgg@...pe.ca,
	kevin.tian@...el.com,
	shuah@...nel.org
Cc: Alessandro Zanni <alessandro.zanni87@...il.com>,
	iommu@...ts.linux.dev,
	linux-kselftest@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] selftests/iommu: prevent use of uninitialized variable

Fix to avoid the usage of the `res` variable uninitialized in the
following macro expansions.

It solves the following warning:
In function ‘iommufd_viommu_vdevice_alloc’,
  inlined from ‘wrapper_iommufd_viommu_vdevice_alloc’ at
iommufd.c:2889:1:
../kselftest_harness.h:760:12: warning: ‘ret’ may be used uninitialized
[-Wmaybe-uninitialized]
  760 |   if (!(__exp _t __seen)) { \
      |      ^
../kselftest_harness.h:513:9: note: in expansion of macro ‘__EXPECT’
  513 |   __EXPECT(expected, #expected, seen, #seen, ==, 1)
      |   ^~~~~~~~
iommufd_utils.h:1057:9: note: in expansion of macro ‘ASSERT_EQ’
 1057 |   ASSERT_EQ(0, _test_cmd_trigger_vevents(self->fd, dev_id,
nvevents))
      |   ^~~~~~~~~
iommufd.c:2924:17: note: in expansion of macro
‘test_cmd_trigger_vevents’
 2924 |   test_cmd_trigger_vevents(dev_id, 3);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~

The issue can be reproduced, building the tests, with the command:
make -C tools/testing/selftests TARGETS=iommu

Signed-off-by: Alessandro Zanni <alessandro.zanni87@...il.com>
---
 tools/testing/selftests/iommu/iommufd_utils.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/iommu/iommufd_utils.h b/tools/testing/selftests/iommu/iommufd_utils.h
index 3c3e08b8c90e..4ae0fcc4f871 100644
--- a/tools/testing/selftests/iommu/iommufd_utils.h
+++ b/tools/testing/selftests/iommu/iommufd_utils.h
@@ -1042,7 +1042,7 @@ static int _test_cmd_trigger_vevents(int fd, __u32 dev_id, __u32 nvevents)
 			.dev_id = dev_id,
 		},
 	};
-	int ret;
+	int ret = 0;
 
 	while (nvevents--) {
 		ret = ioctl(fd, _IOMMU_TEST_CMD(IOMMU_TEST_OP_TRIGGER_VEVENT),
-- 
2.43.0