Do not allocate self->dir_path in the test process because this would not be visible in the FIXTURE_TEARDOWN() process when relying on fork()/clone3() instead of vfork().
This change is required for a following commit removing vfork() call to not break the layout3_fs.* test cases.
Cc: Günther Noack gnoack@google.com Cc: Kees Cook keescook@chromium.org Cc: Shuah Khan skhan@linuxfoundation.org Signed-off-by: Mickaël Salaün mic@digikod.net Link: https://lore.kernel.org/r/20240429130931.2394118-6-mic@digikod.net ---
Changes since v1: * Extract change from a bigger patch (suggested by Kees). --- tools/testing/selftests/landlock/fs_test.c | 57 +++++++++++++--------- 1 file changed, 35 insertions(+), 22 deletions(-)
diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c index 46b9effd53e4..1e2cffde02b5 100644 --- a/tools/testing/selftests/landlock/fs_test.c +++ b/tools/testing/selftests/landlock/fs_test.c @@ -9,6 +9,7 @@
#define _GNU_SOURCE #include <fcntl.h> +#include <libgen.h> #include <linux/landlock.h> #include <linux/magic.h> #include <sched.h> @@ -4624,7 +4625,6 @@ FIXTURE(layout3_fs) { bool has_created_dir; bool has_created_file; - char *dir_path; bool skip_test; };
@@ -4683,11 +4683,24 @@ FIXTURE_VARIANT_ADD(layout3_fs, hostfs) { .cwd_fs_magic = HOSTFS_SUPER_MAGIC, };
+static char *dirname_alloc(const char *path) +{ + char *dup; + + if (!path) + return NULL; + + dup = strdup(path); + if (!dup) + return NULL; + + return dirname(dup); +} + FIXTURE_SETUP(layout3_fs) { struct stat statbuf; - const char *slash; - size_t dir_len; + char *dir_path = dirname_alloc(variant->file_path);
if (!supports_filesystem(variant->mnt.type) || !cwd_matches_fs(variant->cwd_fs_magic)) { @@ -4697,25 +4710,15 @@ FIXTURE_SETUP(layout3_fs)
_metadata->teardown_parent = true;
- slash = strrchr(variant->file_path, '/'); - ASSERT_NE(slash, NULL); - dir_len = (size_t)slash - (size_t)variant->file_path; - ASSERT_LT(0, dir_len); - self->dir_path = malloc(dir_len + 1); - self->dir_path[dir_len] = '\0'; - strncpy(self->dir_path, variant->file_path, dir_len); - prepare_layout_opt(_metadata, &variant->mnt);
/* Creates directory when required. */ - if (stat(self->dir_path, &statbuf)) { + if (stat(dir_path, &statbuf)) { set_cap(_metadata, CAP_DAC_OVERRIDE); - EXPECT_EQ(0, mkdir(self->dir_path, 0700)) + EXPECT_EQ(0, mkdir(dir_path, 0700)) { TH_LOG("Failed to create directory "%s": %s", - self->dir_path, strerror(errno)); - free(self->dir_path); - self->dir_path = NULL; + dir_path, strerror(errno)); } self->has_created_dir = true; clear_cap(_metadata, CAP_DAC_OVERRIDE); @@ -4736,6 +4739,8 @@ FIXTURE_SETUP(layout3_fs) self->has_created_file = true; clear_cap(_metadata, CAP_DAC_OVERRIDE); } + + free(dir_path); }
FIXTURE_TEARDOWN(layout3_fs) @@ -4754,16 +4759,17 @@ FIXTURE_TEARDOWN(layout3_fs) }
if (self->has_created_dir) { + char *dir_path = dirname_alloc(variant->file_path); + set_cap(_metadata, CAP_DAC_OVERRIDE); /* * Don't check for error because the directory might already * have been removed (cf. release_inode test). */ - rmdir(self->dir_path); + rmdir(dir_path); clear_cap(_metadata, CAP_DAC_OVERRIDE); + free(dir_path); } - free(self->dir_path); - self->dir_path = NULL;
cleanup_layout(_metadata); } @@ -4830,7 +4836,10 @@ TEST_F_FORK(layout3_fs, tag_inode_dir_mnt)
TEST_F_FORK(layout3_fs, tag_inode_dir_child) { - layer3_fs_tag_inode(_metadata, self, variant, self->dir_path); + char *dir_path = dirname_alloc(variant->file_path); + + layer3_fs_tag_inode(_metadata, self, variant, dir_path); + free(dir_path); }
TEST_F_FORK(layout3_fs, tag_inode_file) @@ -4857,9 +4866,13 @@ TEST_F_FORK(layout3_fs, release_inodes) if (self->has_created_file) EXPECT_EQ(0, remove_path(variant->file_path));
- if (self->has_created_dir) + if (self->has_created_dir) { + char *dir_path = dirname_alloc(variant->file_path); + /* Don't check for error because of cgroup specificities. */ - remove_path(self->dir_path); + remove_path(dir_path); + free(dir_path); + }
ruleset_fd = create_ruleset(_metadata, LANDLOCK_ACCESS_FS_READ_DIR, layer1);