From: Chaitanya S Prakash chaitanyas.prakash@arm.com
Only valid owning capabilities are allowed to manage memory mappings. Passing a capability with its tag bit cleared will result in failure of the syscall. Tests to verify this behaviour have been added.
Signed-off-by: Chaitanya S Prakash chaitanyas.prakash@arm.com --- tools/testing/selftests/arm64/morello/mmap.c | 95 ++++++++++++++++++++ 1 file changed, 95 insertions(+)
diff --git a/tools/testing/selftests/arm64/morello/mmap.c b/tools/testing/selftests/arm64/morello/mmap.c index 49b6f787f2a2..a1a9ffe9b88a 100644 --- a/tools/testing/selftests/arm64/morello/mmap.c +++ b/tools/testing/selftests/arm64/morello/mmap.c @@ -132,6 +132,100 @@ TEST(test_map_growsdown) EXPECT_EQ((unsigned long)ptr, (unsigned long)-EOPNOTSUPP); }
+/* test to verify invalid capability passed to address space management syscalls + * results in failure of the syscall. + */ +TEST(test_validity_tag_check) +{ + void *ptr, *new_ptr; + int retval; + int prot = PROT_READ | PROT_WRITE; + int flags = MAP_PRIVATE | MAP_ANONYMOUS; + unsigned char vec[MMAP_SIZE / pagesize]; + + /* passing invalid capability to mmap() */ + ptr = mmap(NULL, MMAP_SIZE, prot, flags, -1, 0); + ASSERT_FALSE(IS_ERR_VALUE(ptr)); + new_ptr = mmap(cheri_tag_clear(ptr), MMAP_SIZE_REDUCED, prot, + flags | MAP_FIXED, -1, 0); + EXPECT_EQ((unsigned long)new_ptr, (unsigned long)-EINVAL); + + retval = munmap(ptr, MMAP_SIZE); + ASSERT_EQ(retval, 0); + + /* passing invalid capability to munmap() */ + ptr = mmap(NULL, MMAP_SIZE, prot, flags, -1, 0); + ASSERT_FALSE(IS_ERR_VALUE(ptr)); + EXPECT_EQ(0, probe_mem_range(ptr, MMAP_SIZE, + PROBE_MODE_TOUCH | PROBE_MODE_VERIFY)); + + retval = munmap(cheri_tag_clear(ptr), MMAP_SIZE); + EXPECT_EQ(retval, -EINVAL); + + retval = munmap(ptr, MMAP_SIZE); + ASSERT_EQ(retval, 0); + + /* passing invalid capability to mremap() */ + ptr = mmap(NULL, MMAP_SIZE_REDUCED, prot, flags, -1, 0); + ASSERT_FALSE(IS_ERR_VALUE(ptr)); + new_ptr = mremap(cheri_tag_clear(ptr), MMAP_SIZE_REDUCED, MMAP_SIZE, + MREMAP_MAYMOVE, 0); + EXPECT_EQ((unsigned long)new_ptr, (unsigned long)-EINVAL); + + retval = munmap(ptr, MMAP_SIZE_REDUCED); + ASSERT_EQ(retval, 0); + + /* passing invalid capability to mprotect() */ + ptr = mmap(NULL, MMAP_SIZE, PROT_MAX(prot) | PROT_READ, flags, -1, 0); + ASSERT_FALSE(IS_ERR_VALUE(ptr)); + retval = mprotect(cheri_tag_clear(ptr), MMAP_SIZE, PROT_WRITE); + EXPECT_EQ(retval, -EINVAL); + + retval = munmap(ptr, MMAP_SIZE); + ASSERT_EQ(retval, 0); + + /* as the remaining syscalls are expected to fail in a similar manner, + * have a common mapping. + */ + ptr = mmap(NULL, MMAP_SIZE, prot, flags, -1, 0); + ASSERT_FALSE(IS_ERR_VALUE(ptr)); + + /* passing invalid capability to madvise() */ + retval = madvise(cheri_tag_clear(ptr), MMAP_SIZE, MADV_WILLNEED); + EXPECT_EQ(retval, -EINVAL); + + /* passing invalid capability to mincore() */ + retval = mincore(cheri_tag_clear(ptr), MMAP_SIZE, vec); + EXPECT_EQ(retval, -EINVAL); + + /* passing invalid capability to mlock() */ + retval = mlock(cheri_tag_clear(ptr), MMAP_SIZE); + EXPECT_EQ(retval, -EINVAL); + + /* passing invalid capability to mlock2() */ + retval = mlock2(cheri_tag_clear(ptr), MMAP_SIZE, MLOCK_ONFAULT); + EXPECT_EQ(retval, -EINVAL); + + /* passing invalid capability to munlock() */ + EXPECT_EQ(0, mlock(ptr, MMAP_SIZE_REDUCED)); + EXPECT_EQ(0, probe_mem_range(ptr, MMAP_SIZE_REDUCED, + PROBE_MODE_TOUCH | PROBE_MODE_VERIFY)); + + retval = munlock(cheri_tag_clear(ptr), MMAP_SIZE_REDUCED); + EXPECT_EQ(retval, -EINVAL); + + retval = munlock(ptr, MMAP_SIZE_REDUCED); + ASSERT_EQ(retval, 0); + + /* passing invalid capability to msync() */ + retval = msync(cheri_tag_clear(ptr), MMAP_SIZE, MS_SYNC); + EXPECT_EQ(retval, -EINVAL); + + /* unmap the common mapping */ + retval = munmap(ptr, MMAP_SIZE); + ASSERT_EQ(retval, 0); +} + int main(int argc __maybe_unused, char **argv __maybe_unused, char **envp __maybe_unused, struct morello_auxv *auxv) { @@ -140,5 +234,6 @@ int main(int argc __maybe_unused, char **argv __maybe_unused, char **envp __mayb test_syscall_mmap(); test_syscall_mmap2(); test_map_growsdown(); + test_validity_tag_check(); return 0; }