linux-kernel - Re: [PATCH] selftests/mount_setattr: fix idmap_mount_tree

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

Message-ID: <afe66b04-3990-457c-ad43-9b5370a815d6@163.com>
Date: Fri, 25 Oct 2024 16:08:25 +0800
From: zhouyuhang <zhouyuhang1010@....com>
To: Shuah Khan <skhan@...uxfoundation.org>, brauner@...nel.org,
 sforshee@...nel.org, shuah@...nel.org
Cc: linux-fsdevel@...r.kernel.org, linux-kselftest@...r.kernel.org,
 linux-kernel@...r.kernel.org, zhouyuhang <zhouyuhang@...inos.cn>
Subject: Re: [PATCH] selftests/mount_setattr: fix idmap_mount_tree_invalid
 failed to run



在 2024/10/24 22:26, Shuah Khan 写道:
> On 10/24/24 03:50, zhouyuhang wrote:
>> From: zhouyuhang <zhouyuhang@...inos.cn>
>>
>> Test case idmap_mount_tree_invalid failed to run on the newer kernel
>> with the following output:
>>
>>   #  RUN mount_setattr_idmapped.idmap_mount_tree_invalid ...
>>   # mount_setattr_test.c:1428:idmap_mount_tree_invalid:Expected 
>> sys_mount_setattr(open_tree_fd, "", AT_EMPTY_PATH, &attr, 
>> sizeof(attr)) (0) ! = 0 (0)
>>   # idmap_mount_tree_invalid: Test terminated by assertion
>>
>> This is because tmpfs is mounted at "/mnt/A", and tmpfs already
>> contains the flag FS_ALLOW_IDMAP after the commit 7a80e5b8c6fa ("shmem:
>> support idmapped mounts for tmpfs"). So calling sys_mount_setattr here
>> returns 0 instead of -EINVAL as expected.
>>
>> Ramfs is mounted at "/mnt/B" and does not support idmap mounts.
>> So we can use "/mnt/B" instead of "/mnt/A" to make the test run
>> successfully with the following output:
>>
>>   # Starting 1 tests from 1 test cases.
>>   #  RUN mount_setattr_idmapped.idmap_mount_tree_invalid ...
>>   #            OK mount_setattr_idmapped.idmap_mount_tree_invalid
>>   ok 1 mount_setattr_idmapped.idmap_mount_tree_invalid
>>   # PASSED: 1 / 1 tests passed.
>>
>
> Sounds like this code is testing this very condition passing
> in invalid mount to see what happens. If that is the intent
> this patch is incorrect.
>

I think I probably understand what you mean, what you're saying is that 
the output of this line of errors is the condition,
and the main purpose of the test case is to see what happens when it 
invalid mount. But it's valid now, isn't it?
So we need to fix it. I don't think that constructing this error with 
ramfs will have any impact on the code that follows.
If you feel that using "/mnt/B" is unreliable, I think we can 
temporarily mount ramfs to "/mnt/A" here and continue using "/mnt/A".
Do you think this is feasible? Looking forward to your reply, thank you.

>> Signed-off-by: zhouyuhang <zhouyuhang@...inos.cn>
>> ---
>>   tools/testing/selftests/mount_setattr/mount_setattr_test.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git 
>> a/tools/testing/selftests/mount_setattr/mount_setattr_test.c 
>> b/tools/testing/selftests/mount_setattr/mount_setattr_test.c
>> index c6a8c732b802..54552c19bc24 100644
>> --- a/tools/testing/selftests/mount_setattr/mount_setattr_test.c
>> +++ b/tools/testing/selftests/mount_setattr/mount_setattr_test.c
>> @@ -1414,7 +1414,7 @@ TEST_F(mount_setattr_idmapped, 
>> idmap_mount_tree_invalid)
>>       ASSERT_EQ(expected_uid_gid(-EBADF, "/tmp/B/b", 0, 0, 0), 0);
>>       ASSERT_EQ(expected_uid_gid(-EBADF, "/tmp/B/BB/b", 0, 0, 0), 0);
>>   -    open_tree_fd = sys_open_tree(-EBADF, "/mnt/A",
>> +    open_tree_fd = sys_open_tree(-EBADF, "/mnt/B",
>>                        AT_RECURSIVE |
>>                        AT_EMPTY_PATH |
>>                        AT_NO_AUTOMOUNT |
>
> thanks,
> -- Shuah