From patchwork Fri Mar 22 15:09:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?G=C3=BCnther_Noack?= X-Patchwork-Id: 13600237 Received: from mail-ej1-f73.google.com (mail-ej1-f73.google.com [209.85.218.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 77FF94F897 for ; Fri, 22 Mar 2024 15:10:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711120231; cv=none; b=FW2Gu1izvancmnm6eKzXuTwofqIh779KGWFXvYujI9dlKCqtxv0UQrVILGF3hvvlD4Gxf15b7EXK63TvDkgbBV5+X9sRxtXKXoJiHJz+9+4wW+m9B5fcjolxmIQUvr7LkRpsR3SjfOfD7tu4Uwi/Qee5E4azrXOCUETmOX8FEB0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711120231; c=relaxed/simple; bh=Zui2v1od/elMRFrLL3WvczuYkqdRJ607JihPTYWoBxc=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=MDBNzkbQl4sTvJPHnbzyHZNet5pdDucYuBNHXk6CWkhDCsLb0kqtqbzIRytW4UwiuMdsw9g7HXYpTJLfEyzqZRbTQiTT7gZQQJ0dDCIdm0nzL4mZ7YOFLYX52DG7QcDMzSQVbCJQl9nSzNUaJSvQytLCcgQ2pe7Ld3vjTtsAylM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--gnoack.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=ZXDtZmIg; arc=none smtp.client-ip=209.85.218.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--gnoack.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="ZXDtZmIg" Received: by mail-ej1-f73.google.com with SMTP id a640c23a62f3a-a47103b2261so115311466b.3 for ; Fri, 22 Mar 2024 08:10:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1711120228; x=1711725028; darn=vger.kernel.org; h=content-transfer-encoding:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:from:to:cc:subject:date:message-id :reply-to; bh=l9e1vLBZyU81CA03W1c5FAr2hW3zhJCc3KJ54WTxEPY=; b=ZXDtZmIguQVMivdv/eOsPXtjuDZHr9Zqhl9lzMxoNPQaM6bghCdX9BR9HjPo0/d6TB gC3YxZht84HQh5/8MNoktYxrWaot4+JcaCjOaHpRFF0OX7cNA411EuVySrRLMJ9l+Rf0 guGWShjFk36qUjkkgPoCKYnnuD3SwxAl8VkHPSuvkCb2TVtMAB2fJ4BcJvjsPWe6kLIL 32Q6ahNBOudnMXoMvoTzeuoELpL8UsnS7I2aOh2UpJbPdbnKfivHlDVXOSNlxejByaYK LVjBIaJCbJVbt1UdrF0qW0YLSWUq1Dr51DazQFCnmw5foedCFL1ZzK4wXLPrH2u5Uxs4 B2PA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711120228; x=1711725028; h=content-transfer-encoding:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=l9e1vLBZyU81CA03W1c5FAr2hW3zhJCc3KJ54WTxEPY=; b=Ug4h+evgOmBbU8NSUPsNo8ep2s0x5NX+GpaVaOgqcZTq75dbSUVpsyea1Yd+jKqO8j KcDeBX7lK6pro6C86dsx4jCvM1Ho6bGe6JPSobEUGkCaf7RrUJJh+UBJQK4LHG5Xpz33 QfxIJewyS9kFiozl45sTSkio7YWO9z4K82a37Q0SFelGjH8V+61LOH+Z2AkiTbFz1RfL qekQCVJ1l18ZgUGdBO62YdnXIqCOD74w9sdSXsG4xcixSsSlBYLptzGcUmkxAe0mzzQf 1AF5o3Uz6eCOV1IWHOD5Qd39OPdbpRF2QpsXDK8BS0BdnTm/I832/wVAWfuMFtjSCi7T c0nQ== X-Forwarded-Encrypted: i=1; AJvYcCW1lvooHsIBhaPQ30N7Xyz/BpEwwu+zrrV7WIiQqpgoZ/zTa2tCTdswBMZk/hnYCGD3bYObbAKdqgCpOCIjdorxJnCHwuNJrKgBcGCW9w== X-Gm-Message-State: AOJu0Yx3QykXqH51b94a0XiGhmUwhwlFiXZmgOi4Mi+lWtzKISq2dAhw X2XQ1uHeBlIIFEqgbJcAw12ZLTO5WZyTC8QD6PvcmspqMQHvcdcI7QDiG5CD0wJgLUN4oIoOTOa 4oQ== X-Google-Smtp-Source: AGHT+IG6Ca8DZ4cAM6ldO7A7OzePRWTyWzZ4f5MoTIu+1T3g5D4zS1hMo9S/KsL/azFqdsCMVJKywOvmTqo= X-Received: from swim.c.googlers.com ([fda3:e722:ac3:cc00:31:98fb:c0a8:1605]) (user=gnoack job=sendgmr) by 2002:a17:907:2669:b0:a47:33f1:3ba with SMTP id ci9-20020a170907266900b00a4733f103bamr3ejc.10.1711120227818; Fri, 22 Mar 2024 08:10:27 -0700 (PDT) Date: Fri, 22 Mar 2024 15:09:56 +0000 In-Reply-To: <20240322151002.3653639-1-gnoack@google.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20240322151002.3653639-1-gnoack@google.com> X-Mailer: git-send-email 2.44.0.396.g6e790dbe36-goog Message-ID: <20240322151002.3653639-4-gnoack@google.com> Subject: [PATCH v11 3/9] selftests/landlock: Test IOCTL support From: " =?utf-8?q?G=C3=BCnther_Noack?= " To: linux-security-module@vger.kernel.org, " =?utf-8?q?Micka=C3=ABl_Sala?= =?utf-8?q?=C3=BCn?= " Cc: Jeff Xu , Jorge Lucangeli Obes , Allen Webb , Dmitry Torokhov , Paul Moore , Konstantin Meskhidze , Matt Bobrowski , linux-fsdevel@vger.kernel.org, " =?utf-8?q?G=C3=BCnther_Noack?= " Exercises Landlock's IOCTL feature in different combinations of handling and permitting the LANDLOCK_ACCESS_FS_IOCTL_DEV right, and in different combinations of using files and directories. Signed-off-by: Günther Noack --- tools/testing/selftests/landlock/fs_test.c | 236 ++++++++++++++++++++- 1 file changed, 233 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c index 0bcbbf594fd7..22229fe3e403 100644 --- a/tools/testing/selftests/landlock/fs_test.c +++ b/tools/testing/selftests/landlock/fs_test.c @@ -8,6 +8,7 @@ */ #define _GNU_SOURCE +#include #include #include #include @@ -15,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -23,6 +25,12 @@ #include #include +/* + * Intentionally included last to work around header conflict. + * See https://sourceware.org/glibc/wiki/Synchronizing_Headers. + */ +#include + #include "common.h" #ifndef renameat2 @@ -735,6 +743,9 @@ static int create_ruleset(struct __test_metadata *const _metadata, } for (i = 0; rules[i].path; i++) { + if (!rules[i].access) + continue; + add_path_beneath(_metadata, ruleset_fd, rules[i].access, rules[i].path); } @@ -3443,7 +3454,7 @@ TEST_F_FORK(layout1, truncate_unhandled) LANDLOCK_ACCESS_FS_WRITE_FILE; int ruleset_fd; - /* Enable Landlock. */ + /* Enables Landlock. */ ruleset_fd = create_ruleset(_metadata, handled, rules); ASSERT_LE(0, ruleset_fd); @@ -3526,7 +3537,7 @@ TEST_F_FORK(layout1, truncate) LANDLOCK_ACCESS_FS_TRUNCATE; int ruleset_fd; - /* Enable Landlock. */ + /* Enables Landlock. */ ruleset_fd = create_ruleset(_metadata, handled, rules); ASSERT_LE(0, ruleset_fd); @@ -3752,7 +3763,7 @@ TEST_F_FORK(ftruncate, open_and_ftruncate) }; int fd, ruleset_fd; - /* Enable Landlock. */ + /* Enables Landlock. */ ruleset_fd = create_ruleset(_metadata, variant->handled, rules); ASSERT_LE(0, ruleset_fd); enforce_ruleset(_metadata, ruleset_fd); @@ -3829,6 +3840,16 @@ TEST_F_FORK(ftruncate, open_and_ftruncate_in_different_processes) ASSERT_EQ(0, close(socket_fds[1])); } +/* Invokes the FS_IOC_GETFLAGS IOCTL and returns its errno or 0. */ +static int test_fs_ioc_getflags_ioctl(int fd) +{ + uint32_t flags; + + if (ioctl(fd, FS_IOC_GETFLAGS, &flags) < 0) + return errno; + return 0; +} + TEST(memfd_ftruncate) { int fd; @@ -3845,6 +3866,215 @@ TEST(memfd_ftruncate) ASSERT_EQ(0, close(fd)); } +static int test_fionread_ioctl(int fd) +{ + size_t sz = 0; + + if (ioctl(fd, FIONREAD, &sz) < 0 && errno == EACCES) + return errno; + return 0; +} + +/* clang-format off */ +FIXTURE(ioctl) {}; + +FIXTURE_SETUP(ioctl) {}; + +FIXTURE_TEARDOWN(ioctl) {}; +/* clang-format on */ + +FIXTURE_VARIANT(ioctl) +{ + const __u64 handled; + const __u64 allowed; + const mode_t open_mode; + /* + * TCGETS is used as a characteristic device-specific IOCTL command. + * The logic is the same for other IOCTL commands as well. + */ + const int expected_tcgets_result; /* terminal device IOCTL */ + /* + * FIONREAD is implemented in fs/ioctl.c for regular files, + * but we do not blanket-permit it for devices. + */ + const int expected_fionread_result; +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_i_allowed_none) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_IOCTL_DEV, + .allowed = 0, + .open_mode = O_RDWR, + .expected_tcgets_result = EACCES, + .expected_fionread_result = EACCES, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, handled_i_allowed_i) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_IOCTL_DEV, + .allowed = LANDLOCK_ACCESS_FS_IOCTL_DEV, + .open_mode = O_RDWR, + .expected_tcgets_result = 0, + .expected_fionread_result = 0, +}; + +/* clang-format off */ +FIXTURE_VARIANT_ADD(ioctl, unhandled) { + /* clang-format on */ + .handled = LANDLOCK_ACCESS_FS_EXECUTE, + .allowed = LANDLOCK_ACCESS_FS_EXECUTE, + .open_mode = O_RDWR, + .expected_tcgets_result = 0, + .expected_fionread_result = 0, +}; + +static int test_fioqsize_ioctl(int fd) +{ + size_t sz; + + if (ioctl(fd, FIOQSIZE, &sz) < 0) + return errno; + return 0; +} + +static int test_tcgets_ioctl(int fd) +{ + struct termios info; + + if (ioctl(fd, TCGETS, &info) < 0) + return errno; + return 0; +} + +TEST_F_FORK(ioctl, handle_dir_access_file) +{ + const int flag = 0; + const struct rule rules[] = { + { + .path = "/dev", + .access = variant->allowed, + }, + {}, + }; + int file_fd, ruleset_fd; + + /* Enables Landlock. */ + ruleset_fd = create_ruleset(_metadata, variant->handled, rules); + ASSERT_LE(0, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + ASSERT_EQ(0, close(ruleset_fd)); + + file_fd = open("/dev/tty", variant->open_mode); + ASSERT_LE(0, file_fd); + + /* Checks that IOCTL commands return the expected errors. */ + EXPECT_EQ(variant->expected_tcgets_result, test_tcgets_ioctl(file_fd)); + EXPECT_EQ(variant->expected_fionread_result, + test_fionread_ioctl(file_fd)); + + /* Checks that unrestrictable commands are unrestricted. */ + EXPECT_EQ(0, ioctl(file_fd, FIOCLEX)); + EXPECT_EQ(0, ioctl(file_fd, FIONCLEX)); + EXPECT_EQ(0, ioctl(file_fd, FIONBIO, &flag)); + EXPECT_EQ(0, ioctl(file_fd, FIOASYNC, &flag)); + EXPECT_EQ(ENOTTY, test_fioqsize_ioctl(file_fd)); + + ASSERT_EQ(0, close(file_fd)); +} + +TEST_F_FORK(ioctl, handle_dir_access_dir) +{ + const int flag = 0; + const struct rule rules[] = { + { + .path = "/dev", + .access = variant->allowed, + }, + {}, + }; + int dir_fd, ruleset_fd; + + /* Enables Landlock. */ + ruleset_fd = create_ruleset(_metadata, variant->handled, rules); + ASSERT_LE(0, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + ASSERT_EQ(0, close(ruleset_fd)); + + /* + * Ignore variant->open_mode for this test, as we intend to open a + * directory. If the directory can not be opened, the variant is + * infeasible to test with an opened directory. + */ + dir_fd = open("/dev", O_RDONLY); + if (dir_fd < 0) + return; + + /* + * Checks that IOCTL commands return the expected errors. + * We do not use the expected values from the fixture here. + * + * When using IOCTL on a directory, no Landlock restrictions apply. + * TCGETS will fail anyway because it is not invoked on a TTY device. + */ + EXPECT_EQ(ENOTTY, test_tcgets_ioctl(dir_fd)); + EXPECT_EQ(0, test_fionread_ioctl(dir_fd)); + + /* Checks that unrestrictable commands are unrestricted. */ + EXPECT_EQ(0, ioctl(dir_fd, FIOCLEX)); + EXPECT_EQ(0, ioctl(dir_fd, FIONCLEX)); + EXPECT_EQ(0, ioctl(dir_fd, FIONBIO, &flag)); + EXPECT_EQ(0, ioctl(dir_fd, FIOASYNC, &flag)); + EXPECT_EQ(0, test_fioqsize_ioctl(dir_fd)); + + ASSERT_EQ(0, close(dir_fd)); +} + +TEST_F_FORK(ioctl, handle_file_access_file) +{ + const int flag = 0; + const struct rule rules[] = { + { + .path = "/dev/tty0", + .access = variant->allowed, + }, + {}, + }; + int file_fd, ruleset_fd; + + if (variant->allowed & LANDLOCK_ACCESS_FS_READ_DIR) { + SKIP(return, "LANDLOCK_ACCESS_FS_READ_DIR " + "can not be granted on files"); + } + + /* Enables Landlock. */ + ruleset_fd = create_ruleset(_metadata, variant->handled, rules); + ASSERT_LE(0, ruleset_fd); + enforce_ruleset(_metadata, ruleset_fd); + ASSERT_EQ(0, close(ruleset_fd)); + + file_fd = open("/dev/tty0", variant->open_mode); + ASSERT_LE(0, file_fd) + { + TH_LOG("Failed to open /dev/tty0: %s", strerror(errno)); + } + + /* Checks that IOCTL commands return the expected errors. */ + EXPECT_EQ(variant->expected_tcgets_result, test_tcgets_ioctl(file_fd)); + EXPECT_EQ(variant->expected_fionread_result, + test_fionread_ioctl(file_fd)); + + /* Checks that unrestrictable commands are unrestricted. */ + EXPECT_EQ(0, ioctl(file_fd, FIOCLEX)); + EXPECT_EQ(0, ioctl(file_fd, FIONCLEX)); + EXPECT_EQ(0, ioctl(file_fd, FIONBIO, &flag)); + EXPECT_EQ(0, ioctl(file_fd, FIOASYNC, &flag)); + EXPECT_EQ(ENOTTY, test_fioqsize_ioctl(file_fd)); + + ASSERT_EQ(0, close(file_fd)); +} + /* clang-format off */ FIXTURE(layout1_bind) {}; /* clang-format on */