[LTP] [PATCH v3 09/11] Add landlock04 test

[Li Wang]

Hi Petr, Andrea,

On Wed, Jul 17, 2024 at 1:27 AM Petr Vorel <pvorel@suse.cz> wrote:

> Hi Andrea,
>
> ...
> > +static void enable_exec_libs(const int ruleset_fd)
> > +{
> > +     FILE *fp;
> > +     char line[1024];
> > +     char path[PATH_MAX];
> > +     char dependency[8][PATH_MAX];
> > +     int count = 0;
> > +     int duplicate = 0;
> > +
> > +     fp = SAFE_FOPEN("/proc/self/maps", "r");
> > +
> > +     while (fgets(line, sizeof(line), fp)) {
> > +             if (strstr(line, ".so") == NULL)
> > +                     continue;
> > +
> > +             SAFE_SSCANF(line, "%*x-%*x %*s %*x %*s %*d %s", path);
> > +
> > +             for (int i = 0; i < count; i++) {
> > +                     if (strcmp(path, dependency[i]) == 0) {
> > +                             duplicate = 1;
> > +                             break;
> > +                     }
> > +             }
> > +
> > +             if (duplicate) {
> > +                     duplicate = 0;
> > +                     continue;
> > +             }
> > +
> > +             strncpy(dependency[count], path, PATH_MAX);
> > +             count++;
> > +
> > +             tst_res(TINFO, "Enable read/exec permissions for %s",
> path);
> > +
> > +             path_beneath_attr->allowed_access =
> > +                     LANDLOCK_ACCESS_FS_READ_FILE |
> > +                     LANDLOCK_ACCESS_FS_EXECUTE;
> > +             path_beneath_attr->parent_fd = SAFE_OPEN(path, O_PATH |
> O_CLOEXEC);
> > +
> > +             SAFE_LANDLOCK_ADD_RULE(
> > +                     ruleset_fd,
> > +                     LANDLOCK_RULE_PATH_BENEATH,
> > +                     path_beneath_attr,
> > +                     0);
>
> Unfortunately, on 6.6.15-amd64 kernel (random Debian machine) it fails
> (after
> fresh boot) with:
>
> ...
> tst_supported_fs_types.c:97: TINFO: Kernel supports tmpfs
> tst_supported_fs_types.c:49: TINFO: mkfs is not needed for tmpfs
> tst_test.c:1746: TINFO: === Testing on ext2 ===
> tst_test.c:1111: TINFO: Formatting /dev/loop1 with ext2 opts='' extra
> opts=''
> mke2fs 1.47.0 (5-Feb-2023)
> tst_test.c:1123: TINFO: Mounting /dev/loop1 to /tmp/LTP_lant6WbKJ/sandbox
> fstyp=ext2 flags=0
> landlock_common.h:30: TINFO: Landlock ABI v3
> landlock04.c:151: TINFO: Testing LANDLOCK_ACCESS_FS_EXECUTE
> landlock04.c:123: TINFO: Enable read/exec permissions for
> /usr/lib/i386-linux-gnu/libc.so.6
> landlock04.c:131: TBROK: landlock_add_rule(3, 1, 0xf7f13ff4, 0): EINVAL
> (22)
>

Possibly that's because the 'LANDLOCK_RULE_PATH_BENEATH'  was
refactored from the v6.7 mainline kernel, so it can't add the rule correctly
with older kernels.

commit 0e0fc7e8eb4a11bd9f89a9c74bc7c0e144c56203
Author: Konstantin Meskhidze <konstantin.meskhidze@huawei.com>
Date:   Thu Oct 26 09:47:46 2023 +0800

    landlock: Refactor landlock_add_rule() syscall

But this is my guess (through reading the code), I didn't do more to
verify that by installing such a kernel.


-- 
Regards,
Li Wang