Re: [PATCH v2 2/2] selftests/filesystems: allow security.selinux xattr in listxattr kernfs test

[Yeswanth Krishna <yeswanth@linux.ibm.com>]

On 21/05/26 3:47 pm, Disha Goel wrote:

> kernfs_test assumes that flistxattr() on /sys/kernel/warn_count always
> returns an empty list. However, systems with SELinux enabled may expose
> security.selinux xattr via listxattr() during policy load, which makes
> the test fail even though kernfs is behaving correctly.
>
> Allow security.selinux xattr in kernfs_listxattr while continuing to
> reject other unexpected xattrs. Keep the existing user.foo getxattr
> check unchanged.
>
> This avoids false failures on SELinux-enabled systems while preserving
> the original purpose of the test.
>
> Signed-off-by: Disha Goel<disgoel@linux.ibm.com>
> ---

Hi Disha,

I have tested this patch on my ppc64le system and it works as expected.

Test Environment:
- Kernel: Linux (mainline)

Logs
====
# make -C tools/testing/selftests/filesystems run_tests
make: Entering directory '/root/linux/tools/testing/selftests/filesystems'
# timeout set to 45
# selftests: filesystems: kernfs_test
# TAP version 13
# 1..2
# # Starting 2 tests from 1 test cases.
# #  RUN           global.kernfs_listxattr ...
# #            OK  global.kernfs_listxattr
# ok 1 global.kernfs_listxattr
# #  RUN           global.kernfs_getxattr ...
# #            OK  global.kernfs_getxattr
# ok 2 global.kernfs_getxattr
# # PASSED: 2 / 2 tests passed.
# # Totals: pass:2 fail:0 xfail:0 xpass:0 skip:0 error:0
ok 3 selftests: filesystems: kernfs_test
|All filesystem selftests also passed without issues.|

Please add below tag.

Tested-by: Yeswanth Krishna<yeswanth@linux.ibm.com>

Thanks,
Yeswanth Krishna

>   .../selftests/filesystems/kernfs_test.c       | 27 +++++++++++++++++--
>   1 file changed, 25 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/filesystems/kernfs_test.c b/tools/testing/selftests/filesystems/kernfs_test.c
> index 84c2b910a60d..a5e480d662e0 100644
> --- a/tools/testing/selftests/filesystems/kernfs_test.c
> +++ b/tools/testing/selftests/filesystems/kernfs_test.c
> @@ -4,6 +4,8 @@
>   
>   #include <fcntl.h>
>   #include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
>   #include <sys/stat.h>
>   #include <sys/xattr.h>
>   
> @@ -12,12 +14,33 @@
>   
>   TEST(kernfs_listxattr)
>   {
> +	char *buf, *xattr;
> +	ssize_t len, ret;
>   	int fd;
>   
> -	/* Read-only file that can never have any extended attributes set. */
> +	/* Read-only file that can never have any extended attributes set.
> +	 * However, SELinux may set security.selinux xattr on kernfs files
> +	 * during policy load, so we explicitly ignore it.
> +	 */
>   	fd = open("/sys/kernel/warn_count", O_RDONLY | O_CLOEXEC);
>   	ASSERT_GE(fd, 0);
> -	ASSERT_EQ(flistxattr(fd, NULL, 0), 0);
> +
> +	len = flistxattr(fd, NULL, 0);
> +	ASSERT_GE(len, 0);
> +
> +	if (len > 0) {
> +		buf = malloc(len);
> +		ASSERT_NE(buf, NULL);
> +
> +		ret = flistxattr(fd, buf, len);
> +		ASSERT_EQ(ret, len);
> +
> +		for (xattr = buf; xattr < buf + len; xattr += strlen(xattr) + 1)
> +			ASSERT_EQ(strcmp(xattr, "security.selinux"), 0);
> +
> +		free(buf);
> +	}
> +
>   	EXPECT_EQ(close(fd), 0);
>   }
>