@@ -1187,6 +1187,7 @@ shmctl01 shmctl01
shmctl02 shmctl02
shmctl03 shmctl03
shmctl04 shmctl04
+shmctl05 shmctl05
shmdt01 shmdt01
shmdt02 shmdt02
@@ -53,6 +53,7 @@ shmctl01 shmctl01
shmctl02 shmctl02
shmctl03 shmctl03
shmctl04 shmctl04
+shmctl05 shmctl05
shmdt01 shmdt01
shmdt02 shmdt02
@@ -2,3 +2,4 @@
/shmctl02
/shmctl03
/shmctl04
+/shmctl05
@@ -18,6 +18,9 @@
top_srcdir ?= ../../../../..
+shmctl05: CFLAGS += -pthread
+shmctl05: LDLIBS += -lrt
+
include $(top_srcdir)/include/mk/testcases.mk
include $(abs_srcdir)/../Makefile.inc
include $(top_srcdir)/include/mk/generic_leaf_target.mk
new file mode 100644
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2018 Google, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program, if not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * Regression test for commit 3f05317d9889 ("ipc/shm: fix use-after-free of shm
+ * file via remap_file_pages()"). This bug allowed the remap_file_pages()
+ * syscall to use the file of a System V shared memory segment after its ID had
+ * been reallocated and the file freed. This test reproduces the bug as a NULL
+ * pointer dereference in touch_atime(), although it's a race condition so it's
+ * not guaranteed to work. This test is based on the reproducer provided in the
+ * fix's commit message.
+ */
+
+#include "lapi/syscalls.h"
+#include "tst_test.h"
+#include "tst_fuzzy_sync.h"
+#include "tst_safe_pthread.h"
+#include "tst_safe_sysv_ipc.h"
+#include "tst_timer.h"
+
+static struct tst_fzsync_pair fzsync_pair = TST_FZSYNC_PAIR_INIT;
+
+static pthread_t thrd;
+
+/*
+ * Thread 2: repeatedly remove the shm ID and reallocate it again for a
+ * new shm segment.
+ */
+static void *thrproc(void *unused)
+{
+ int id = SAFE_SHMGET(0xF00F, 4096, IPC_CREAT|0700);
+
+ for (;;) {
+ if (!tst_fzsync_wait_b(&fzsync_pair))
+ break;
+ SAFE_SHMCTL(id, IPC_RMID, NULL);
+ id = SAFE_SHMGET(0xF00F, 4096, IPC_CREAT|0700);
+ if (!tst_fzsync_wait_b(&fzsync_pair))
+ break;
+ }
+ return unused;
+}
+
+static void setup(void)
+{
+ tst_timer_check(CLOCK_MONOTONIC);
+
+ /* Skip test if either remap_file_pages() or SysV IPC is unavailable */
+ tst_syscall(__NR_remap_file_pages, NULL, 0, 0, 0, 0);
+ tst_syscall(__NR_shmctl, 0xF00F, IPC_RMID, NULL);
+
+ SAFE_PTHREAD_CREATE(&thrd, NULL, thrproc, NULL);
+}
+
+static void do_test(void)
+{
+ tst_timer_start(CLOCK_MONOTONIC);
+
+ /*
+ * Thread 1: repeatedly attach a shm segment, then remap it until the ID
+ * seems to have been removed by the other process.
+ */
+ while (!tst_timer_expired_ms(5000)) {
+ int id;
+ void *addr;
+
+ id = SAFE_SHMGET(0xF00F, 4096, IPC_CREAT|0700);
+ addr = SAFE_SHMAT(id, NULL, 0);
+ tst_fzsync_wait_a(&fzsync_pair);
+ do {
+ /* This is the system call that crashed */
+ TEST(syscall(__NR_remap_file_pages, addr, 4096,
+ 0, 0, 0));
+ } while (TEST_RETURN == 0);
+
+ if (TEST_ERRNO != EIDRM && TEST_ERRNO != EINVAL) {
+ tst_brk(TBROK | TTERRNO,
+ "Unexpected remap_file_pages() error");
+ }
+ tst_fzsync_wait_a(&fzsync_pair);
+ }
+
+ tst_res(TPASS, "didn't crash");
+}
+
+static void cleanup(void)
+{
+ if (thrd) {
+ tst_fzsync_pair_exit(&fzsync_pair);
+ SAFE_PTHREAD_JOIN(thrd, NULL);
+ }
+ shmctl(0xF00F, IPC_RMID, NULL);
+}
+
+static struct tst_test test = {
+ .timeout = 20,
+ .setup = setup,
+ .test_all = do_test,
+ .cleanup = cleanup,
+};