[LTP] [PATCH] squashfs: Add regression test for sanity check bug

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> Adds a regression test for the fixes
> c1b2028315 ("squashfs: fix inode lookup sanity checks ???")
> and
> 8b44ca2b62 ("squashfs: fix xattr id and id lookup sanity checks")
> 
> Signed-off-by: Joerg Vehlow <joerg.vehlow@aox-tech.de>
> ---
>  runtest/fs                                    |  2 +
>  testcases/kernel/fs/squashfs/.gitignore       |  1 +
>  testcases/kernel/fs/squashfs/Makefile         | 11 +++
>  .../kernel/fs/squashfs/squashfs-createfiles.c | 84 +++++++++++++++++++
>  .../kernel/fs/squashfs/squashfs_regression.sh | 65 ++++++++++++++
>  5 files changed, 163 insertions(+)
>  create mode 100644 testcases/kernel/fs/squashfs/.gitignore
>  create mode 100644 testcases/kernel/fs/squashfs/Makefile
>  create mode 100644 testcases/kernel/fs/squashfs/squashfs-createfiles.c
>  create mode 100755 testcases/kernel/fs/squashfs/squashfs_regression.sh
> 
> diff --git a/runtest/fs b/runtest/fs
> index 17b1415eb..a01eaf41d 100644
> --- a/runtest/fs
> +++ b/runtest/fs
> @@ -85,3 +85,5 @@ fs_fill fs_fill
>  
>  binfmt_misc01 binfmt_misc01.sh
>  binfmt_misc02 binfmt_misc02.sh
> +
> +squashfs_regression_sh squashfs_regression.sh
> diff --git a/testcases/kernel/fs/squashfs/.gitignore b/testcases/kernel/fs/squashfs/.gitignore
> new file mode 100644
> index 000000000..ca1306b99
> --- /dev/null
> +++ b/testcases/kernel/fs/squashfs/.gitignore
> @@ -0,0 +1 @@
> +squashfs-createfiles
> diff --git a/testcases/kernel/fs/squashfs/Makefile b/testcases/kernel/fs/squashfs/Makefile
> new file mode 100644
> index 000000000..f4e854fa2
> --- /dev/null
> +++ b/testcases/kernel/fs/squashfs/Makefile
> @@ -0,0 +1,11 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +# Copyright (C) 2009, Cisco Systems Inc.
> +# Ngie Cooper, July 2009
> +
> +top_srcdir		?= ../../../..
> +
> +include $(top_srcdir)/include/mk/testcases.mk
> +
> +INSTALL_TARGETS := squashfs_regression.sh
> +
> +include $(top_srcdir)/include/mk/generic_leaf_target.mk
> diff --git a/testcases/kernel/fs/squashfs/squashfs-createfiles.c b/testcases/kernel/fs/squashfs/squashfs-createfiles.c
> new file mode 100644
> index 000000000..e7808041f
> --- /dev/null
> +++ b/testcases/kernel/fs/squashfs/squashfs-createfiles.c
> @@ -0,0 +1,84 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2021 Joerg Vehlow <joerg.vehlow@aox-tech.de>
> + *
> + * Simple c program for fast batch creation of dummy files,
> + * it can also set unique uid/gid combinations and xattr for
> + * all files creates. The same as shell code is extremely slower.
> + */
> +
> +
> +#include <stdlib.h>
> +#include <stdio.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include <unistd.h>
> +#include <fcntl.h>
> +#include <sys/xattr.h>
> +
> +#define TST_NO_DEFAULT_MAIN
> +#include "tst_test.h"
> +#include "tst_safe_macros.h"
> +
> +void print_usage(const char *name)
> +{
> +    printf("Usage: %s [OPTION]\n\n", name);
> +    printf("Creates n files in the current directory names 0,1,...\n\n");
> +    printf(" -n n    the number of files to create (default: 2048)\n");
> +    printf(" -c      set uid and groupid of file i to i:i\n");
> +    printf(" -x      set xattr security.x of file i to i\n");
> +    printf(" -h      this message\n");
> +}
> +
> +int main(int argc, char** argv)
> +{
> +    int i;
> +    int option;
> +    int nfiles = 2048;
> +    int set_owner = 0;
> +    int set_xattr = 0;
> +
> +	while ((option = getopt(argc, argv, "n:cxh")) != -1) {
> +		switch (option) {
> +		case 'n':
> +			if (tst_parse_int(optarg, &nfiles, 0, INT_MAX)) {
> +                printf("Value for -n is invalid\n");
> +                print_usage(argv[0]);
> +                return EXIT_FAILURE;
> +            }
> +			break;
> +        case 'c':
> +            set_owner = 1;
> +            break;
> +        case 'x':
> +            set_xattr = 1;
> +            break;
> +		case 'h':
> +			print_usage(argv[0]);
> +			return EXIT_SUCCESS;
> +		default:
> +			print_usage(argv[0]);
> +			return EXIT_FAILURE;
> +		}
> +	}
> +
> +    for (i = 0; i < nfiles; ++i)
> +    {
> +        int fd;
> +        char name[20];
> +        sprintf(name, "%d", i);
> +        fd = SAFE_OPEN(name, O_CREAT | O_EXCL, 0666);
> +        if (set_owner)
> +            SAFE_FCHOWN(fd, i, i);
> +
> +        /* This must be either security, user or trusted namespace.
> +         * Nothing else can be stores in squashfs.
> +         * Since the files are most likely created on a tmpfs,
> +         * user is also not possible, because it is not allowed on tmpfs. */
> +        if (set_xattr)
> +            SAFE_FSETXATTR(fd, "security.x", &i, sizeof(i), XATTR_CREATE);
> +        close(fd);
> +    }
> +
> +    return 0;

The whitespaces are mostly wrong in this part, looks like tabs and
spaces mixed together. Have you tried to run the patch trough the kernel
checkpatch.pl script?

> +}
> diff --git a/testcases/kernel/fs/squashfs/squashfs_regression.sh b/testcases/kernel/fs/squashfs/squashfs_regression.sh
> new file mode 100755
> index 000000000..8d3b8812c
> --- /dev/null
> +++ b/testcases/kernel/fs/squashfs/squashfs_regression.sh
> @@ -0,0 +1,65 @@
> +#!/bin/sh
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +# Copyright (c) 2021 Joerg Vehlow <joerg.vehlow@aox-tech.de>
> +#
> +# This is a regression test for squashfs.
> +# See test comment for details.
> +
> +TST_TESTFUNC=test
> +TST_CLEANUP=cleanup
> +TST_NEEDS_CMDS=mksquashfs
> +TST_NEEDS_ROOT=1
> +TST_NEEDS_TMPDIR=1
> +
> +. tst_test.sh
> +
> +cleanup()
> +{
> +    umount mnt >/dev/null 2>&1
> +}
> +
> +
> +# For inodes: 1023 (+1) entries
> +# For ids: 2048
> +# Fox xattr: 512
> +
> +test1()
> +{
> +    # Kernel commits
> +    #  - f37aa4c7366e23f91b81d00bafd6a7ab54e4a381
> +    #  - eabac19e40c095543def79cb6ffeb3a8588aaff4
> +    #  - 506220d2ba21791314af569211ffd8870b8208fa
> +    # added some sanity checks, that verified the size of
> +    # inode lookup, id (uid/gid) and xattr blocks in the squashfs,
> +    # but roke mounting filesystems with completely filled blocks.
> +    # A block has a max size of 8192.
> +    # An inode lookup entry has an uncompressed size of 8 bytes,
> +    # an id block 4 bytes and an xattr block 16 bytes.
> +    #
> +    # To fill up at least one block for each of the three tables,
> +    # 2048 files with unique uid/gid and xattr are created.
> +    #
> +    # The bugs are fixed in kernel commits
> +    #  - c1b2028315c6b15e8d6725e0d5884b15887d3daa
> +    #  - 8b44ca2b634527151af07447a8090a5f3a043321
> +
> +    tst_res TINFO "Test squashfs sanity check regressions"
> +
> +    mkdir data
> +    cd data
> +    ROD squashfs-createfiles -cxn 2048
> +    cd ..
> +
> +    # Create squashfs without any comporession.
> +    # This allows reasoning about block sizes
> +    mksquashfs data image.raw -noI -noD -noX -noF >/dev/null 2>&1
> +    squashfs-info image.raw
> +
> +    mkdir mnt
> +    EXPECT_PASS_BRK mount -o loop image.raw mnt
> +    umount mnt
> +
> +    tst_res TPASS "Test passed"
> +}
> +
> +tst_run

Given how simple is this part it may be easier to code the whole test in
C instead.

-- 
Cyril Hrubis
chrubis@suse.cz