[LTP] [PATCH v2] chmod08.c: Block mode changes of symlinks

[Andrea Cervesato]

Hi Wei,

there's already a patch doing that. I wrote it long time ago, but it's 
pending for review. Please take a look if you are interested:
https://patchwork.ozlabs.org/project/ltp/patch/20240220131319.11761-1-andrea.cervesato@suse.de/

Andrea

On 5/24/24 10:56, Wei Gao via ltp wrote:
> Signed-off-by: Wei Gao <wegao@suse.com>
> ---
>   runtest/syscalls                           |  1 +
>   testcases/kernel/syscalls/chmod/.gitignore |  1 +
>   testcases/kernel/syscalls/chmod/chmod08.c  | 67 ++++++++++++++++++++++
>   3 files changed, 69 insertions(+)
>   create mode 100644 testcases/kernel/syscalls/chmod/chmod08.c
>
> diff --git a/runtest/syscalls b/runtest/syscalls
> index fe9ad0895..5754d8195 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -70,6 +70,7 @@ chmod03 chmod03
>   chmod05 chmod05
>   chmod06 chmod06
>   chmod07 chmod07
> +chmod08 chmod08
>   
>   chown01 chown01
>   chown01_16 chown01_16
> diff --git a/testcases/kernel/syscalls/chmod/.gitignore b/testcases/kernel/syscalls/chmod/.gitignore
> index 27ddfce16..f295f4dcb 100644
> --- a/testcases/kernel/syscalls/chmod/.gitignore
> +++ b/testcases/kernel/syscalls/chmod/.gitignore
> @@ -3,3 +3,4 @@
>   /chmod05
>   /chmod06
>   /chmod07
> +/chmod08
> diff --git a/testcases/kernel/syscalls/chmod/chmod08.c b/testcases/kernel/syscalls/chmod/chmod08.c
> new file mode 100644
> index 000000000..368a1d635
> --- /dev/null
> +++ b/testcases/kernel/syscalls/chmod/chmod08.c
> @@ -0,0 +1,67 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2024 Wei Gao <wegao@suse.com>
> + */
> +
> +/*\
> + * [Description]
> + *
> + * Test for kernel commit
> + * 5d1f903f75a8 ("attr: block mode changes of symlinks")
> + */
> +
> +#include "lapi/fcntl.h"
> +#include "tst_test.h"
> +
> +#define MODE 0644
> +#define TESTFILE "testfile"
> +#define TESTFILE_SYMLINK "testfile_symlink"
> +
> +static void run(void)
> +{
> +	struct stat stat_file, stat_sym;
> +	int mode = 0;
> +	char fd_path[100];
> +
> +	int fd = SAFE_OPEN(TESTFILE_SYMLINK, O_PATH | O_NOFOLLOW);
> +
> +	sprintf(fd_path, "/proc/self/fd/%d", fd);
> +
> +	TST_EXP_FAIL(chmod(fd_path, mode), ENOTSUP, "chmod(%s, %04o)",
> +			TESTFILE_SYMLINK, mode);
> +
> +	SAFE_STAT(TESTFILE, &stat_file);
> +	SAFE_LSTAT(TESTFILE_SYMLINK, &stat_sym);
> +
> +	stat_file.st_mode &= ~S_IFREG;
> +	stat_sym.st_mode &= ~S_IFLNK;
> +
> +	TST_EXP_EXPR(stat_file.st_mode != (unsigned int)mode,
> +			"stat(%s) mode=%04o", TESTFILE, stat_file.st_mode);
> +
> +	TST_EXP_EXPR(stat_sym.st_mode != (unsigned int)mode,
> +			"stat(%s) mode=%04o", TESTFILE, stat_sym.st_mode);
> +
> +	SAFE_CLOSE(fd);
> +}
> +
> +static void setup(void)
> +{
> +	SAFE_TOUCH(TESTFILE, MODE, NULL);
> +	SAFE_SYMLINK(TESTFILE, TESTFILE_SYMLINK);
> +}
> +
> +static void cleanup(void)
> +{
> +	remove(TESTFILE);
> +	remove(TESTFILE_SYMLINK);
> +}
> +
> +static struct tst_test test = {
> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.test_all = run,
> +	.min_kver = "6.6",
> +	.mntpoint = "mntpoint",
> +	.all_filesystems = 1
> +};