Subject: [PATCH] Add test for more file systems in landlock - ext4

Subject: [PATCH] Add test for more file systems in landlock - ext4

[Saasha Gupta]

Date: Mon, 2 Apr 2024 19:59:56 +0530

RE: This patch is now properly preformatted.

Landlock LSM, a part of the security subsystem, has some tests in place
for synthetic filesystems such as tmpfs, proc, sysfs, etc. The goal of
the new issue, and hence this patch is to add tests for non synthetic
file systems, such as ext4, btrfs, etc

This patch adds tests for the ext4 file system. This includes creation
of a loop device (test-ext4.img) and formating with mkfs.

Signed-off-by: Saasha Gupta <saashaa1122@gmail.com>
---
 tools/testing/selftests/landlock/fs_test.c | 65 ++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
index 9a6036fbf..b2f2cd5a5 100644
--- a/tools/testing/selftests/landlock/fs_test.c
+++ b/tools/testing/selftests/landlock/fs_test.c
@@ -4675,6 +4675,14 @@ FIXTURE_VARIANT_ADD(layout3_fs, hostfs) {
 	.cwd_fs_magic = HOSTFS_SUPER_MAGIC,
 };
 
+/* Add more filesystems */
+FIXTURE_VARIANT_ADD(layout3_fs, ext4) {
+	.mnt = {
+		.type = "ext4",
+	},
+	.file_path = TMP_DIR "/dir/file",
+};
+
 FIXTURE_SETUP(layout3_fs)
 {
 	struct stat statbuf;
@@ -4728,6 +4736,63 @@ FIXTURE_SETUP(layout3_fs)
 		self->has_created_file = true;
 		clear_cap(_metadata, CAP_DAC_OVERRIDE);
 	}
+
+	/* Create non synthetic file system - ext4 */
+	if (stat(self->dir_path, &statbuf) != 0) {
+		pid_t pid = fork();
+
+		if (pid == -1) {
+			perror("Failed to fork");
+			exit(EXIT_FAILURE);
+		} else if (pid == 0) {
+			static const fallocate_argv[] = { "fallocate", "--length",
+						   "4M", "test-ext4.img",
+						   NULL };
+			execvp(fallocate_argv[0], fallocate_argv);
+			perror("execvp failed");
+			exit(EXIT_FAILURE);
+		} else {
+			int status;
+
+			if (waitpid(pid, &status, 0) == -1) {
+				perror("waitpid failed");
+				exit(EXIT_FAILURE);
+			}
+			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+				TH_LOG(stderr,
+					"Failed to create ext4 filesystem image: fallocate failed\n");
+				exit(EXIT_FAILURE);
+			}
+		}
+	}
+
+	/* Formate and mount non synthetic file system - ext4 */
+	if (stat("mnt", &statbuf) != 0) {
+		pid_t pid = fork();
+
+		if (pid == -1) {
+			perror("Failed to fork");
+			exit(EXIT_FAILURE);
+		} else if (pid == 0) {
+			static const mkfs_argv[] = { "mkfs.ext4", "-q",
+					      "test-ext4.img", "mnt", NULL };
+			execvp(mkfs_argv[0], mkfs_argv);
+			perror("execvp failed");
+			exit(EXIT_FAILURE);
+		} else {
+			int status;
+
+			if (waitpid(pid, &status, 0) == -1) {
+				perror("waitpid failed");
+				exit(EXIT_FAILURE);
+			}
+			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+				TH_LOG(stderr,
+					"Failed to format ext4 filesystem image: mkfs.ext4 failed\n");
+				exit(EXIT_FAILURE);
+			}
+		}
+	}
 }
 
 FIXTURE_TEARDOWN(layout3_fs)
-- 
2.44.0

Re: Subject: [PATCH] Add test for more file systems in landlock - ext4

[Julia Lawall]

On Tue, 2 Apr 2024, Saasha Gupta wrote:

> Date: Mon, 2 Apr 2024 19:59:56 +0530

Not clear why this is part of the message.

> RE: This patch is now properly preformatted.

Such a comment belongs below the ---.  People who look at the history of
the file in the git logs have no idea that the patch was previously ill
formatted.

julia

>
> Landlock LSM, a part of the security subsystem, has some tests in place
> for synthetic filesystems such as tmpfs, proc, sysfs, etc. The goal of
> the new issue, and hence this patch is to add tests for non synthetic
> file systems, such as ext4, btrfs, etc
>
> This patch adds tests for the ext4 file system. This includes creation
> of a loop device (test-ext4.img) and formating with mkfs.
>
> Signed-off-by: Saasha Gupta <saashaa1122@gmail.com>
> ---
>  tools/testing/selftests/landlock/fs_test.c | 65 ++++++++++++++++++++++
>  1 file changed, 65 insertions(+)
>
> diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
> index 9a6036fbf..b2f2cd5a5 100644
> --- a/tools/testing/selftests/landlock/fs_test.c
> +++ b/tools/testing/selftests/landlock/fs_test.c
> @@ -4675,6 +4675,14 @@ FIXTURE_VARIANT_ADD(layout3_fs, hostfs) {
>  	.cwd_fs_magic = HOSTFS_SUPER_MAGIC,
>  };
>
> +/* Add more filesystems */
> +FIXTURE_VARIANT_ADD(layout3_fs, ext4) {
> +	.mnt = {
> +		.type = "ext4",
> +	},
> +	.file_path = TMP_DIR "/dir/file",
> +};
> +
>  FIXTURE_SETUP(layout3_fs)
>  {
>  	struct stat statbuf;
> @@ -4728,6 +4736,63 @@ FIXTURE_SETUP(layout3_fs)
>  		self->has_created_file = true;
>  		clear_cap(_metadata, CAP_DAC_OVERRIDE);
>  	}
> +
> +	/* Create non synthetic file system - ext4 */
> +	if (stat(self->dir_path, &statbuf) != 0) {
> +		pid_t pid = fork();
> +
> +		if (pid == -1) {
> +			perror("Failed to fork");
> +			exit(EXIT_FAILURE);
> +		} else if (pid == 0) {
> +			static const fallocate_argv[] = { "fallocate", "--length",
> +						   "4M", "test-ext4.img",
> +						   NULL };
> +			execvp(fallocate_argv[0], fallocate_argv);
> +			perror("execvp failed");
> +			exit(EXIT_FAILURE);
> +		} else {
> +			int status;
> +
> +			if (waitpid(pid, &status, 0) == -1) {
> +				perror("waitpid failed");
> +				exit(EXIT_FAILURE);
> +			}
> +			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
> +				TH_LOG(stderr,
> +					"Failed to create ext4 filesystem image: fallocate failed\n");
> +				exit(EXIT_FAILURE);
> +			}
> +		}
> +	}
> +
> +	/* Formate and mount non synthetic file system - ext4 */
> +	if (stat("mnt", &statbuf) != 0) {
> +		pid_t pid = fork();
> +
> +		if (pid == -1) {
> +			perror("Failed to fork");
> +			exit(EXIT_FAILURE);
> +		} else if (pid == 0) {
> +			static const mkfs_argv[] = { "mkfs.ext4", "-q",
> +					      "test-ext4.img", "mnt", NULL };
> +			execvp(mkfs_argv[0], mkfs_argv);
> +			perror("execvp failed");
> +			exit(EXIT_FAILURE);
> +		} else {
> +			int status;
> +
> +			if (waitpid(pid, &status, 0) == -1) {
> +				perror("waitpid failed");
> +				exit(EXIT_FAILURE);
> +			}
> +			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
> +				TH_LOG(stderr,
> +					"Failed to format ext4 filesystem image: mkfs.ext4 failed\n");
> +				exit(EXIT_FAILURE);
> +			}
> +		}
> +	}
>  }
>
>  FIXTURE_TEARDOWN(layout3_fs)
> --
> 2.44.0
>
>
>
>

Re: Subject: [PATCH] Add test for more file systems in landlock - ext4

[Julia Lawall]

On Tue, 2 Apr 2024, Saasha Gupta wrote:

> Date: Mon, 2 Apr 2024 19:59:56 +0530
>
> RE: This patch is now properly preformatted.
>
> Landlock LSM, a part of the security subsystem, has some tests in place
> for synthetic filesystems such as tmpfs, proc, sysfs, etc. The goal of
> the new issue, and hence this patch is to add tests for non synthetic
> file systems, such as ext4, btrfs, etc

Not clear what "the new issue" could be.  Remember that the log message
will be read by people 10 years from now.  Not just by the recipientes of
the patch.

> This patch adds tests for the ext4 file system. This includes creation
> of a loop device (test-ext4.img) and formating with mkfs.

This should be "Add tests for the ext4 file system".
You seem to have joined application period quite late, but you need to
read the entirety of the tutorial and be prepared to follow it, at least
in the future.

julia

>
> Signed-off-by: Saasha Gupta <saashaa1122@gmail.com>
> ---
>  tools/testing/selftests/landlock/fs_test.c | 65 ++++++++++++++++++++++
>  1 file changed, 65 insertions(+)
>
> diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
> index 9a6036fbf..b2f2cd5a5 100644
> --- a/tools/testing/selftests/landlock/fs_test.c
> +++ b/tools/testing/selftests/landlock/fs_test.c
> @@ -4675,6 +4675,14 @@ FIXTURE_VARIANT_ADD(layout3_fs, hostfs) {
>  	.cwd_fs_magic = HOSTFS_SUPER_MAGIC,
>  };
>
> +/* Add more filesystems */
> +FIXTURE_VARIANT_ADD(layout3_fs, ext4) {
> +	.mnt = {
> +		.type = "ext4",
> +	},
> +	.file_path = TMP_DIR "/dir/file",
> +};
> +
>  FIXTURE_SETUP(layout3_fs)
>  {
>  	struct stat statbuf;
> @@ -4728,6 +4736,63 @@ FIXTURE_SETUP(layout3_fs)
>  		self->has_created_file = true;
>  		clear_cap(_metadata, CAP_DAC_OVERRIDE);
>  	}
> +
> +	/* Create non synthetic file system - ext4 */
> +	if (stat(self->dir_path, &statbuf) != 0) {
> +		pid_t pid = fork();
> +
> +		if (pid == -1) {
> +			perror("Failed to fork");
> +			exit(EXIT_FAILURE);
> +		} else if (pid == 0) {
> +			static const fallocate_argv[] = { "fallocate", "--length",
> +						   "4M", "test-ext4.img",
> +						   NULL };
> +			execvp(fallocate_argv[0], fallocate_argv);
> +			perror("execvp failed");
> +			exit(EXIT_FAILURE);
> +		} else {
> +			int status;
> +
> +			if (waitpid(pid, &status, 0) == -1) {
> +				perror("waitpid failed");
> +				exit(EXIT_FAILURE);
> +			}
> +			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
> +				TH_LOG(stderr,
> +					"Failed to create ext4 filesystem image: fallocate failed\n");
> +				exit(EXIT_FAILURE);
> +			}
> +		}
> +	}
> +
> +	/* Formate and mount non synthetic file system - ext4 */
> +	if (stat("mnt", &statbuf) != 0) {
> +		pid_t pid = fork();
> +
> +		if (pid == -1) {
> +			perror("Failed to fork");
> +			exit(EXIT_FAILURE);
> +		} else if (pid == 0) {
> +			static const mkfs_argv[] = { "mkfs.ext4", "-q",
> +					      "test-ext4.img", "mnt", NULL };
> +			execvp(mkfs_argv[0], mkfs_argv);
> +			perror("execvp failed");
> +			exit(EXIT_FAILURE);
> +		} else {
> +			int status;
> +
> +			if (waitpid(pid, &status, 0) == -1) {
> +				perror("waitpid failed");
> +				exit(EXIT_FAILURE);
> +			}
> +			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
> +				TH_LOG(stderr,
> +					"Failed to format ext4 filesystem image: mkfs.ext4 failed\n");
> +				exit(EXIT_FAILURE);
> +			}
> +		}
> +	}
>  }
>
>  FIXTURE_TEARDOWN(layout3_fs)
> --
> 2.44.0
>
>
>
>

Re: Subject: [PATCH] Add test for more file systems in landlock - ext4

[Mickaël Salaün]

On Tue, Apr 02, 2024 at 01:37:44PM +0530, Saasha Gupta wrote:
> Date: Mon, 2 Apr 2024 19:59:56 +0530
> 
> RE: This patch is now properly preformatted.
> 
> Landlock LSM, a part of the security subsystem, has some tests in place
> for synthetic filesystems such as tmpfs, proc, sysfs, etc. The goal of
> the new issue, and hence this patch is to add tests for non synthetic
> file systems, such as ext4, btrfs, etc

I agree with Julia's review.

> 
> This patch adds tests for the ext4 file system. This includes creation
> of a loop device (test-ext4.img) and formating with mkfs.
> 
> Signed-off-by: Saasha Gupta <saashaa1122@gmail.com>
> ---
>  tools/testing/selftests/landlock/fs_test.c | 65 ++++++++++++++++++++++
>  1 file changed, 65 insertions(+)
> 
> diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
> index 9a6036fbf..b2f2cd5a5 100644
> --- a/tools/testing/selftests/landlock/fs_test.c
> +++ b/tools/testing/selftests/landlock/fs_test.c
> @@ -4675,6 +4675,14 @@ FIXTURE_VARIANT_ADD(layout3_fs, hostfs) {
>  	.cwd_fs_magic = HOSTFS_SUPER_MAGIC,
>  };
>  
> +/* Add more filesystems */
> +FIXTURE_VARIANT_ADD(layout3_fs, ext4) {
> +	.mnt = {
> +		.type = "ext4",
> +	},
> +	.file_path = TMP_DIR "/dir/file",
> +};
> +
>  FIXTURE_SETUP(layout3_fs)
>  {
>  	struct stat statbuf;
> @@ -4728,6 +4736,63 @@ FIXTURE_SETUP(layout3_fs)
>  		self->has_created_file = true;
>  		clear_cap(_metadata, CAP_DAC_OVERRIDE);
>  	}
> +
> +	/* Create non synthetic file system - ext4 */
> +	if (stat(self->dir_path, &statbuf) != 0) {

dir_path should already exist with previous code right?

> +		pid_t pid = fork();
> +
> +		if (pid == -1) {
> +			perror("Failed to fork");
> +			exit(EXIT_FAILURE);
> +		} else if (pid == 0) {
> +			static const fallocate_argv[] = { "fallocate", "--length",
> +						   "4M", "test-ext4.img",
> +						   NULL };
> +			execvp(fallocate_argv[0], fallocate_argv);

Using system() would makes this much simpler (see net_test.c).

> +			perror("execvp failed");
> +			exit(EXIT_FAILURE);
> +		} else {
> +			int status;
> +
> +			if (waitpid(pid, &status, 0) == -1) {
> +				perror("waitpid failed");
> +				exit(EXIT_FAILURE);
> +			}
> +			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
> +				TH_LOG(stderr,
> +					"Failed to create ext4 filesystem image: fallocate failed\n");
> +				exit(EXIT_FAILURE);
> +			}
> +		}
> +	}
> +
> +	/* Formate and mount non synthetic file system - ext4 */
> +	if (stat("mnt", &statbuf) != 0) {

"mnt" never exists, so this would always run this code...

> +		pid_t pid = fork();
> +
> +		if (pid == -1) {
> +			perror("Failed to fork");
> +			exit(EXIT_FAILURE);
> +		} else if (pid == 0) {
> +			static const mkfs_argv[] = { "mkfs.ext4", "-q",
> +					      "test-ext4.img", "mnt", NULL };
> +			execvp(mkfs_argv[0], mkfs_argv);
> +			perror("execvp failed");
> +			exit(EXIT_FAILURE);
> +		} else {
> +			int status;
> +
> +			if (waitpid(pid, &status, 0) == -1) {
> +				perror("waitpid failed");
> +				exit(EXIT_FAILURE);
> +			}
> +			if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
> +				TH_LOG(stderr,
> +					"Failed to format ext4 filesystem image: mkfs.ext4 failed\n");
> +				exit(EXIT_FAILURE);
> +			}
> +		}
> +	}
>  }
>  
>  FIXTURE_TEARDOWN(layout3_fs)
> -- 
> 2.44.0
> 
> 
>