[LTP] [PATCH v3] open15: allow restricted O_CREAT of FIFOs and regular files

[Andrea Cervesato]

Hi Wei,

If we want to merge this patch, we need to do a couple of things more.
The open15 is now taken by an another test, so we need to move it to open16.
Also we don't have a nice git commit message describing what's the 
purpose of the test.

On 6/3/24 14:55, Wei Gao via ltp wrote:
> Fix: #574
>
> Signed-off-by: Wei Gao <wegao@suse.com>
> ---
>   runtest/syscalls                          |   1 +
>   testcases/kernel/syscalls/open/.gitignore |   1 +
>   testcases/kernel/syscalls/open/open15.c   | 125 ++++++++++++++++++++++
>   3 files changed, 127 insertions(+)
>   create mode 100644 testcases/kernel/syscalls/open/open15.c
>
> diff --git a/runtest/syscalls b/runtest/syscalls
> index 4f1ee1f34..4152e1e5f 100644
> --- a/runtest/syscalls
> +++ b/runtest/syscalls
> @@ -935,6 +935,7 @@ open11 open11
>   open12 open12
>   open13 open13
>   open14 open14
> +open15 open15
>   
>   openat01 openat01
>   openat02 openat02
> diff --git a/testcases/kernel/syscalls/open/.gitignore b/testcases/kernel/syscalls/open/.gitignore
> index 001d874d6..af5997572 100644
> --- a/testcases/kernel/syscalls/open/.gitignore
> +++ b/testcases/kernel/syscalls/open/.gitignore
> @@ -12,3 +12,4 @@
>   /open12_child
>   /open13
>   /open14
> +/open15
> diff --git a/testcases/kernel/syscalls/open/open15.c b/testcases/kernel/syscalls/open/open15.c
> new file mode 100644
> index 000000000..de5325e01
> --- /dev/null
> +++ b/testcases/kernel/syscalls/open/open15.c
> @@ -0,0 +1,125 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2023 Wei Gao <wegao@suse.com>
> + */
> +
> +/*\
> + * [Description]
Not needed anymore.
> + *
> + * Verify disallows open of FIFOs or regular files not owned by the user in world
> + * writable sticky directories
> + *
> + * commit 30aba6656f61ed44cba445a3c0d38b296fa9e8f5
> + * Author: Salvatore Mesoraca <s.mesoraca16@gmail.com>
> + * Date:   Thu Aug 23 17:00:35 2018 -0700
> + *     namei: allow restricted O_CREAT of FIFOs and regular files
we should update .tags instead of copying commit message here.
> + */
> +
> +#include <pwd.h>
> +#include <stdlib.h>
> +#include "tst_test.h"
> +#include "tst_safe_file_at.h"
> +
> +#define  FILENAME  "setuid04_testfile"
> +#define  DIR "ltp_tmp_check1"
> +#define  TEST_FILE "test_file_1"
> +#define  TEST_FIFO "test_fifo_1"
> +#define  LTP_USR_UID1 1000
> +#define  LTP_USR_UID2 1001
> +#define  CONCAT(dir, filename) dir "/" filename
> +#define  PROTECTED_REGULAR "/proc/sys/fs/protected_regular"
> +#define  PROTECTED_FIFOS "/proc/sys/fs/protected_fifos"
> +
> +static int dir_fd;
> +
> +static void run(void)
> +{
> +	int pid;
> +
> +	SAFE_CHMOD(DIR, 0777 | S_ISVTX);
> +	SAFE_FILE_PRINTF(PROTECTED_REGULAR, "%d", 0);
> +	SAFE_FILE_PRINTF(PROTECTED_FIFOS, "%d", 0);
> +
> +	if (!SAFE_FORK()) {
> +		SAFE_SETUID(LTP_USR_UID1);
> +
> +		int fd = TST_EXP_FD(openat(dir_fd, TEST_FILE, O_CREAT | O_RDWR, 0777));
> +
> +		SAFE_CLOSE(fd);
> +
> +		SAFE_MKFIFO(CONCAT(DIR, TEST_FIFO), 0777);
> +
> +		exit(0);
> +	}
> +
> +	tst_reap_children();
> +
> +	if (!SAFE_FORK()) {
> +		SAFE_SETUID(LTP_USR_UID2);
> +
> +		int fd = TST_EXP_FD(openat(dir_fd, TEST_FILE, O_CREAT | O_RDWR, 0777));
> +
> +		SAFE_CLOSE(fd);
> +
> +		fd = TST_EXP_FD(open(CONCAT(DIR, TEST_FIFO), O_RDWR | O_CREAT, 0777));
> +		SAFE_CLOSE(fd);
> +
> +		exit(0);
> +	}
> +
> +	tst_reap_children();
> +
> +	SAFE_FILE_PRINTF(PROTECTED_REGULAR, "%d", 1);
> +	SAFE_FILE_PRINTF(PROTECTED_FIFOS, "%d", 1);
> +
> +	if (!SAFE_FORK()) {
> +		SAFE_SETUID(LTP_USR_UID2);
> +		TST_EXP_FAIL(openat(dir_fd, TEST_FILE, O_RDWR | O_CREAT, 0777), EACCES);
> +		TST_EXP_FAIL(open(CONCAT(DIR, TEST_FIFO), O_RDWR | O_CREAT, 0777), EACCES);
> +
> +		exit(0);
> +	}
> +
> +	tst_reap_children();
> +
> +	SAFE_FILE_PRINTF(PROTECTED_REGULAR, "%d", 2);
> +	SAFE_FILE_PRINTF(PROTECTED_FIFOS, "%d", 2);
> +	SAFE_CHMOD(DIR, 0020 | S_ISVTX);
> +
> +	if (!SAFE_FORK()) {
> +		SAFE_SETUID(LTP_USR_UID2);
> +		TST_EXP_FAIL(openat(dir_fd, TEST_FILE, O_RDWR | O_CREAT, 0777), EACCES);
> +		TST_EXP_FAIL(open(CONCAT(DIR, TEST_FIFO), O_RDWR | O_CREAT, 0777), EACCES);
> +
> +		exit(0);
> +	}
> +
> +	tst_reap_children();
> +	unlink(CONCAT(DIR, TEST_FIFO));
SAFE_UNLINK()
> +}
> +
> +static void setup(void)
> +{
> +	umask(0);
> +	SAFE_MKDIR(DIR, 0777 | S_ISVTX);
> +	dir_fd = SAFE_OPEN(DIR, O_DIRECTORY);
> +}
> +
> +static void cleanup(void)
> +{
> +	SAFE_CLOSE(dir_fd);

if (dir_fd != -1)
     SAFE_CLOSE(dir_fd);

> +}
> +
> +static struct tst_test test = {
> +	.setup = setup,
> +	.cleanup = cleanup,
> +	.needs_root = 1,
> +	.test_all = run,
> +	.needs_tmpdir = 1,
> +	.forks_child = 1,
> +	.save_restore = (const struct tst_path_val[]) {
> +		{PROTECTED_REGULAR, NULL, TST_SR_TCONF},
> +		{PROTECTED_FIFOS, NULL, TST_SR_TCONF},
> +		{}
> +	},
.tags is missing.
> +};
Andrea