The ioctl audit test uses FIONREAD, whose command value fits in 16 bits. It therefore cannot detect truncation of encoded direction and size bits.
Use an architecture-independent unknown command with set upper bits and require its complete value in the audit record. Landlock rejects the command before the device handles it, and the existing ioctl enforcement test already exercises the same request. The new expectation fails with ioctlcmd=0xfeee on an unfixed kernel and passes with ioctlcmd=0xc00ffeee after the shared audit field is widened. Signed-off-by: Mickaël Salaün <[email protected]> --- tools/testing/selftests/landlock/fs_test.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c index 18dbdb99aeba..1abdcc9ee784 100644 --- a/tools/testing/selftests/landlock/fs_test.c +++ b/tools/testing/selftests/landlock/fs_test.c @@ -4146,6 +4146,9 @@ TEST_F_FORK(layout1, o_path_ftruncate_and_ioctl) ASSERT_EQ(0, close(fd)); } +/* Arbitrary command with nonzero bits in both 16-bit halves. */ +static const unsigned int unknown_ioctl_cmd = 0xc00ffeee; + /* * ioctl_error - generically call the given ioctl with a pointer to a * sufficiently large zeroed-out memory region. @@ -4249,7 +4252,7 @@ TEST_F_FORK(layout1, blanket_permitted_ioctls) EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FS_IOC_ZERO_RANGE)); /* Default case is also blocked. */ - EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, 0xc00ffeee)); + EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, unknown_ioctl_cmd)); ASSERT_EQ(0, close(fd)); } @@ -7943,6 +7946,7 @@ TEST_F(audit_layout1, truncate) EXPECT_EQ(1, records.domain); } +/* Checks that audit records preserve every ioctl command bit. */ TEST_F(audit_layout1, ioctl_dev) { struct audit_records records; @@ -7952,10 +7956,10 @@ TEST_F(audit_layout1, ioctl_dev) fd = open("/dev/null", O_RDONLY | O_CLOEXEC); ASSERT_LE(0, fd); - EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, FIONREAD)); + EXPECT_EQ(EACCES, ioctl_error(_metadata, fd, unknown_ioctl_cmd)); EXPECT_EQ(0, matches_log_fs_extra(_metadata, self->audit_fd, "fs\\.ioctl_dev", "/dev/null", - " ioctlcmd=0x541b")); + " ioctlcmd=0xc00ffeee")); EXPECT_EQ(0, audit_count_records(self->audit_fd, &records)); EXPECT_EQ(0, records.access); -- 2.55.0
