Verify that a shortened vector supplied through PR_SET_MM_AUXV has a valid AT_NULL terminator when exposed through /proc/self/auxv. This catches stale AUXV entries left beyond the supplied vector.
Signed-off-by: Sahaj Chaudhari <[email protected]> --- tools/testing/selftests/prctl/.gitignore | 1 + tools/testing/selftests/prctl/Makefile | 1 + .../testing/selftests/prctl/pr_set_mm_auxv.c | 42 +++++++++++++++++++ 3 files changed, 44 insertions(+) create mode 100644 tools/testing/selftests/prctl/pr_set_mm_auxv.c diff --git a/tools/testing/selftests/prctl/.gitignore b/tools/testing/selftests/prctl/.gitignore index 05d5e31661dfd..089af0296aeca 100644 --- a/tools/testing/selftests/prctl/.gitignore +++ b/tools/testing/selftests/prctl/.gitignore @@ -4,3 +4,4 @@ disable-tsc-on-off-stress-test disable-tsc-test set-anon-vma-name-test set-process-name +pr_set_mm_auxv diff --git a/tools/testing/selftests/prctl/Makefile b/tools/testing/selftests/prctl/Makefile index e770e86fad9ac..a21811a8f6a06 100644 --- a/tools/testing/selftests/prctl/Makefile +++ b/tools/testing/selftests/prctl/Makefile @@ -6,6 +6,7 @@ override ARCH := $(shell echo $(ARCH) | sed -e s/i.86/x86/ -e s/x86_64/x86/) ifeq ($(ARCH),x86) TEST_PROGS := disable-tsc-ctxt-sw-stress-test disable-tsc-on-off-stress-test \ disable-tsc-test set-anon-vma-name-test set-process-name +TEST_GEN_PROGS := pr_set_mm_auxv all: $(TEST_PROGS) include ../lib.mk diff --git a/tools/testing/selftests/prctl/pr_set_mm_auxv.c b/tools/testing/selftests/prctl/pr_set_mm_auxv.c new file mode 100644 index 0000000000000..934ff480c0f4d --- /dev/null +++ b/tools/testing/selftests/prctl/pr_set_mm_auxv.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <elf.h> +#include <errno.h> +#include <fcntl.h> +#include <sys/prctl.h> +#include <unistd.h> + +#include "kselftest_harness.h" + +TEST(set_mm_auxv_terminator) +{ + unsigned long auxv[] = { + AT_UID, 0x1111, + AT_GID, 0x2222, + }; + unsigned long result[64]; + ssize_t len; + int fd; + + if (prctl(PR_SET_MM, PR_SET_MM_AUXV, (unsigned long)auxv, + sizeof(auxv), 0)) { + if (errno == EPERM) + SKIP(return, "requires CAP_SYS_RESOURCE"); + ASSERT_EQ(errno, 0); + } + + fd = open("/proc/self/auxv", O_RDONLY); + ASSERT_GE(fd, 0); + + len = read(fd, result, sizeof(result)); + close(fd); + + ASSERT_GE(len, (ssize_t)(6 * sizeof(unsigned long))); + EXPECT_EQ(result[0], (unsigned long)AT_UID); + EXPECT_EQ(result[1], 0x1111UL); + EXPECT_EQ(result[2], (unsigned long)AT_GID); + EXPECT_EQ(result[3], 0x2222UL); + EXPECT_EQ(result[4], (unsigned long)AT_NULL); + EXPECT_EQ(result[5], 0UL); +} + +TEST_HARNESS_MAIN -- 2.43.0
