[LTP] [PATCH v2 2/2] Add test for CVE 2017-1000405
Martin Doucha
mdoucha@suse.cz
Wed Jul 1 17:14:56 CEST 2020
Fixes #316
Signed-off-by: Martin Doucha <mdoucha@suse.cz>
---
Changes since v1:
- include lapi/mmap.h
- TCONF if madvise(MADV_HUGEPAGE) fails with EINVAL
runtest/cve | 1 +
runtest/mm | 1 +
testcases/kernel/mem/.gitignore | 1 +
testcases/kernel/mem/thp/Makefile | 1 +
testcases/kernel/mem/thp/thp04.c | 160 ++++++++++++++++++++++++++++++
5 files changed, 164 insertions(+)
create mode 100644 testcases/kernel/mem/thp/thp04.c
diff --git a/runtest/cve b/runtest/cve
index a3a25dbe1..fdb455af1 100644
--- a/runtest/cve
+++ b/runtest/cve
@@ -43,6 +43,7 @@ cve-2017-18075 pcrypt_aead01
cve-2017-1000111 setsockopt07
cve-2017-1000112 setsockopt05
cve-2017-1000380 snd_timer01
+cve-2017-1000405 thp04
cve-2018-5803 sctp_big_chunk
cve-2018-7566 snd_seq01
cve-2018-8897 ptrace09
diff --git a/runtest/mm b/runtest/mm
index 612a4d066..4701a14bd 100644
--- a/runtest/mm
+++ b/runtest/mm
@@ -86,6 +86,7 @@ swapping01 swapping01 -i 5
thp01 thp01 -I 120
thp02 thp02
thp03 thp03
+thp04 thp04
vma01 vma01
vma02 vma02
diff --git a/testcases/kernel/mem/.gitignore b/testcases/kernel/mem/.gitignore
index ce21ca70f..b95ada109 100644
--- a/testcases/kernel/mem/.gitignore
+++ b/testcases/kernel/mem/.gitignore
@@ -65,6 +65,7 @@
/thp/thp01
/thp/thp02
/thp/thp03
+/thp/thp04
/tunable/max_map_count
/tunable/min_free_kbytes
/tunable/overcommit_memory
diff --git a/testcases/kernel/mem/thp/Makefile b/testcases/kernel/mem/thp/Makefile
index 867dcf089..89abdc7cd 100644
--- a/testcases/kernel/mem/thp/Makefile
+++ b/testcases/kernel/mem/thp/Makefile
@@ -18,6 +18,7 @@
#
top_srcdir ?= ../../../..
+thp04: LDLIBS += -lrt
include $(top_srcdir)/include/mk/testcases.mk
include $(top_srcdir)/testcases/kernel/mem/include/libmem.mk
diff --git a/testcases/kernel/mem/thp/thp04.c b/testcases/kernel/mem/thp/thp04.c
new file mode 100644
index 000000000..a8d806c42
--- /dev/null
+++ b/testcases/kernel/mem/thp/thp04.c
@@ -0,0 +1,160 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 SUSE LLC <mdoucha@suse.cz>
+ */
+
+/*
+ * CVE-2017-1000405
+ *
+ * Check for the Huge Dirty Cow vulnerability which allows a userspace process
+ * to overwrite the huge zero page. Race fixed in:
+ *
+ * commit a8f97366452ed491d13cf1e44241bc0b5740b1f0
+ * Author: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+ * Date: Mon Nov 27 06:21:25 2017 +0300
+ *
+ * mm, thp: Do not make page table dirty unconditionally in touch_p[mu]d()
+ */
+
+#include <sys/mman.h>
+
+#include "tst_test.h"
+#include "lapi/mmap.h"
+#include "tst_fuzzy_sync.h"
+
+static char *write_thp, *read_thp;
+static int *write_ptr, *read_ptr;
+static size_t thp_size;
+static int writefd = -1, readfd = -1;
+static struct tst_fzsync_pair fzsync_pair;
+
+static void *alloc_zero_page(void *baseaddr)
+{
+ int i;
+ void *ret;
+
+ /* Find aligned chunk of address space. MAP_HUGETLB doesn't work. */
+ for (i = 0; i < 16; i++, baseaddr += thp_size) {
+ ret = mmap(baseaddr, thp_size, PROT_READ,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+ if (ret == baseaddr) {
+ TEST(madvise(ret, thp_size, MADV_HUGEPAGE));
+
+ if (TST_RET == -1 && TST_ERR == EINVAL) {
+ tst_brk(TCONF | TTERRNO,
+ "madvise(MADV_HUGEPAGE) not supported");
+ }
+
+ if (TST_RET) {
+ tst_brk(TBROK | TTERRNO,
+ "madvise(MADV_HUGEPAGE) failed");
+ }
+
+ return ret;
+ }
+
+ if (ret != MAP_FAILED)
+ SAFE_MUNMAP(ret, thp_size);
+ }
+
+ tst_brk(TBROK, "Cannot map huge zero page near the specified address");
+ return NULL; /* Silence compiler warning */
+}
+
+static void setup(void)
+{
+ size_t i;
+
+ thp_size = tst_get_hugepage_size();
+
+ if (!thp_size)
+ tst_brk(TCONF, "Kernel does not support huge pages");
+
+ write_thp = alloc_zero_page((void*)thp_size);
+
+ for (i = 0; i < thp_size; i++) {
+ if (write_thp[i]) {
+ tst_brk(TCONF, "Huge zero page is pre-polluted");
+ }
+ }
+
+ /* leave a hole between read and write THP to prevent merge */
+ read_thp = alloc_zero_page(write_thp + 2 * thp_size);
+ write_ptr = (int*)(write_thp + thp_size - sizeof(int));
+ read_ptr = (int*)(read_thp + thp_size - sizeof(int));
+ writefd = SAFE_OPEN("/proc/self/mem", O_RDWR);
+ readfd = SAFE_OPEN("/proc/self/mem", O_RDWR);
+
+ fzsync_pair.exec_loops = 100000;
+ tst_fzsync_pair_init(&fzsync_pair);
+}
+
+static void *thread_run(void *arg)
+{
+ int c;
+
+ while (tst_fzsync_run_b(&fzsync_pair)) {
+ tst_fzsync_start_race_b(&fzsync_pair);
+ madvise(write_thp, thp_size, MADV_DONTNEED);
+ memcpy(&c, write_ptr, sizeof(c));
+ SAFE_LSEEK(readfd, (off_t)write_ptr, SEEK_SET);
+ SAFE_READ(1, readfd, &c, sizeof(int));
+ tst_fzsync_end_race_b(&fzsync_pair);
+ /* Wait for dirty page handling before next madvise() */
+ usleep(10);
+ }
+
+ return arg;
+}
+
+static void run(void)
+{
+ int c = 0xdeadbeef;
+
+ tst_fzsync_pair_reset(&fzsync_pair, thread_run);
+
+ while (tst_fzsync_run_a(&fzsync_pair)) {
+ /* Write into the main huge page */
+ tst_fzsync_start_race_a(&fzsync_pair);
+ SAFE_LSEEK(writefd, (off_t)write_ptr, SEEK_SET);
+ madvise(write_thp, thp_size, MADV_DONTNEED);
+ SAFE_WRITE(1, writefd, &c, sizeof(int));
+ tst_fzsync_end_race_a(&fzsync_pair);
+
+ /* Check the other huge zero page for pollution */
+ madvise(read_thp, thp_size, MADV_DONTNEED);
+
+ if (*read_ptr != 0) {
+ tst_res(TFAIL, "Huge zero page was polluted");
+ return;
+ }
+ }
+
+ tst_res(TPASS, "Huge zero page is still clean");
+}
+
+static void cleanup(void)
+{
+ tst_fzsync_pair_cleanup(&fzsync_pair);
+
+ if (readfd >= 0)
+ SAFE_CLOSE(readfd);
+
+ if (writefd >= 0)
+ SAFE_CLOSE(writefd);
+
+ SAFE_MUNMAP(read_thp, thp_size);
+ SAFE_MUNMAP(write_thp, thp_size);
+}
+
+static struct tst_test test = {
+ .test_all = run,
+ .setup = setup,
+ .cleanup = cleanup,
+ .tags = (const struct tst_tag[]) {
+ {"linux-git", "a8f97366452e"},
+ {"CVE", "2017-1000405"},
+ {}
+ }
+};
--
2.26.2
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