diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-07-27 13:16:53 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-07-27 13:16:53 -0700 |
commit | 86b405ad8d0d2994a7ffbacb8fcf83be8afb952c (patch) | |
tree | 52907a427269ad6c951894da45c1149d7a6ee753 /tools | |
parent | 8e333791d4605dbce611c22f71a86721c9afc336 (diff) | |
parent | cc374782b6ca0fd634482391da977542443d3368 (diff) |
Merge tag 'landlock-6.11-rc1-houdini-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux
Pull landlock fix from Mickaël Salaün:
"Jann Horn reported a sandbox bypass for Landlock. This includes the
fix and new tests. This should be backported"
* tag 'landlock-6.11-rc1-houdini-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux:
selftests/landlock: Add cred_transfer test
landlock: Don't lose track of restrictions on cred_transfer
Diffstat (limited to 'tools')
-rw-r--r-- | tools/testing/selftests/landlock/base_test.c | 74 | ||||
-rw-r--r-- | tools/testing/selftests/landlock/config | 1 |
2 files changed, 75 insertions, 0 deletions
diff --git a/tools/testing/selftests/landlock/base_test.c b/tools/testing/selftests/landlock/base_test.c index 3c1e9f35b531..3b26bf3cf5b9 100644 --- a/tools/testing/selftests/landlock/base_test.c +++ b/tools/testing/selftests/landlock/base_test.c @@ -9,6 +9,7 @@ #define _GNU_SOURCE #include <errno.h> #include <fcntl.h> +#include <linux/keyctl.h> #include <linux/landlock.h> #include <string.h> #include <sys/prctl.h> @@ -326,4 +327,77 @@ TEST(ruleset_fd_transfer) ASSERT_EQ(EXIT_SUCCESS, WEXITSTATUS(status)); } +TEST(cred_transfer) +{ + struct landlock_ruleset_attr ruleset_attr = { + .handled_access_fs = LANDLOCK_ACCESS_FS_READ_DIR, + }; + int ruleset_fd, dir_fd; + pid_t child; + int status; + + drop_caps(_metadata); + + dir_fd = open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC); + EXPECT_LE(0, dir_fd); + EXPECT_EQ(0, close(dir_fd)); + + /* Denies opening directories. */ + ruleset_fd = + landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); + ASSERT_LE(0, ruleset_fd); + EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); + ASSERT_EQ(0, landlock_restrict_self(ruleset_fd, 0)); + EXPECT_EQ(0, close(ruleset_fd)); + + /* Checks ruleset enforcement. */ + EXPECT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC)); + EXPECT_EQ(EACCES, errno); + + /* Needed for KEYCTL_SESSION_TO_PARENT permission checks */ + EXPECT_NE(-1, syscall(__NR_keyctl, KEYCTL_JOIN_SESSION_KEYRING, NULL, 0, + 0, 0)) + { + TH_LOG("Failed to join session keyring: %s", strerror(errno)); + } + + child = fork(); + ASSERT_LE(0, child); + if (child == 0) { + /* Checks ruleset enforcement. */ + EXPECT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC)); + EXPECT_EQ(EACCES, errno); + + /* + * KEYCTL_SESSION_TO_PARENT is a no-op unless we have a + * different session keyring in the child, so make that happen. + */ + EXPECT_NE(-1, syscall(__NR_keyctl, KEYCTL_JOIN_SESSION_KEYRING, + NULL, 0, 0, 0)); + + /* + * KEYCTL_SESSION_TO_PARENT installs credentials on the parent + * that never go through the cred_prepare hook, this path uses + * cred_transfer instead. + */ + EXPECT_EQ(0, syscall(__NR_keyctl, KEYCTL_SESSION_TO_PARENT, 0, + 0, 0, 0)); + + /* Re-checks ruleset enforcement. */ + EXPECT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC)); + EXPECT_EQ(EACCES, errno); + + _exit(_metadata->exit_code); + return; + } + + EXPECT_EQ(child, waitpid(child, &status, 0)); + EXPECT_EQ(1, WIFEXITED(status)); + EXPECT_EQ(EXIT_SUCCESS, WEXITSTATUS(status)); + + /* Re-checks ruleset enforcement. */ + EXPECT_EQ(-1, open("/", O_RDONLY | O_DIRECTORY | O_CLOEXEC)); + EXPECT_EQ(EACCES, errno); +} + TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/landlock/config b/tools/testing/selftests/landlock/config index 0086efaa7b68..29af19c4e9f9 100644 --- a/tools/testing/selftests/landlock/config +++ b/tools/testing/selftests/landlock/config @@ -2,6 +2,7 @@ CONFIG_CGROUPS=y CONFIG_CGROUP_SCHED=y CONFIG_INET=y CONFIG_IPV6=y +CONFIG_KEYS=y CONFIG_NET=y CONFIG_NET_NS=y CONFIG_OVERLAY_FS=y |