[LTP] [PATCH v3] syscalls/prctl04.c: New test for prctl() with PR_{SET, GET}_SECCOMP
Yang Xu
xuyang2018.jy@cn.fujitsu.com
Thu May 23 04:54:00 CEST 2019
Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
---
configure.ac | 1 +
include/lapi/prctl.h | 5 +
include/lapi/seccomp.h | 40 ++++
runtest/syscalls | 1 +
testcases/kernel/syscalls/prctl/.gitignore | 1 +
testcases/kernel/syscalls/prctl/prctl04.c | 231 +++++++++++++++++++++
6 files changed, 279 insertions(+)
create mode 100644 include/lapi/seccomp.h
create mode 100644 testcases/kernel/syscalls/prctl/prctl04.c
diff --git a/configure.ac b/configure.ac
index 5dc85728a..5a3dc5b62 100644
--- a/configure.ac
+++ b/configure.ac
@@ -46,6 +46,7 @@ AC_CHECK_HEADERS([ \
linux/mempolicy.h \
linux/module.h \
linux/netlink.h \
+ linux/seccomp.h \
linux/userfaultfd.h \
mm.h \
netinet/sctp.h \
diff --git a/include/lapi/prctl.h b/include/lapi/prctl.h
index 6db8a6480..f42bd6459 100644
--- a/include/lapi/prctl.h
+++ b/include/lapi/prctl.h
@@ -9,6 +9,11 @@
#include <sys/prctl.h>
+#ifndef PR_SET_SECCOMP
+# define PR_GET_SECCOMP 21
+# define PR_SET_SECCOMP 22
+#endif
+
#ifndef PR_SET_CHILD_SUBREAPER
# define PR_SET_CHILD_SUBREAPER 36
# define PR_GET_CHILD_SUBREAPER 37
diff --git a/include/lapi/seccomp.h b/include/lapi/seccomp.h
new file mode 100644
index 000000000..a80d3d8cd
--- /dev/null
+++ b/include/lapi/seccomp.h
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 FUJITSU LIMITED. All rights reserved.
+ * Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
+ */
+#ifndef LAPI_SECCOMP_H
+#define LAPI_SECCOMP_H
+
+# include <linux/types.h>
+
+# ifdef HAVE_LINUX_SECCOMP_H
+# include <linux/seccomp.h>
+# else
+/* Valid values for seccomp.mode and prctl(PR_SET_SECCOMP, <mode>) */
+# define SECCOMP_MODE_DISABLED 0
+# define SECCOMP_MODE_STRICT 1
+# define SECCOMP_MODE_FILTER 2
+
+# define SECCOMP_RET_KILL_THREAD 0x00000000U /* kill the thread */
+# define SECCOMP_RET_KILL SECCOMP_RET_KILL_THREAD
+# define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */
+
+/**
+ * struct seccomp_data - the format the BPF program executes over.
+ * @nr: the system call number
+ * @arch: indicates system call convention as an AUDIT_ARCH_* value
+ * as defined in <linux/audit.h>.
+ * @instruction_pointer: at the time of the system call.
+ * @args: up to 6 system call arguments always stored as 64-bit values
+ * regardless of the architecture.
+ */
+struct seccomp_data {
+ int nr;
+ __u32 arch;
+ __u64 instruction_pointer;
+ __u64 args[6];
+};
+
+# endif /* HAVE_LINUX_SECCOMP_H*/
+#endif /* LAPI_SECCOMP_H */
diff --git a/runtest/syscalls b/runtest/syscalls
index 30c132751..04558a580 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -861,6 +861,7 @@ ppoll01 ppoll01
prctl01 prctl01
prctl02 prctl02
prctl03 prctl03
+prctl04 prctl04
pread01 pread01
pread01_64 pread01_64
diff --git a/testcases/kernel/syscalls/prctl/.gitignore b/testcases/kernel/syscalls/prctl/.gitignore
index 2f46a9a12..1c3da3052 100644
--- a/testcases/kernel/syscalls/prctl/.gitignore
+++ b/testcases/kernel/syscalls/prctl/.gitignore
@@ -1,3 +1,4 @@
/prctl01
/prctl02
/prctl03
+/prctl04
diff --git a/testcases/kernel/syscalls/prctl/prctl04.c b/testcases/kernel/syscalls/prctl/prctl04.c
new file mode 100644
index 000000000..585274a8a
--- /dev/null
+++ b/testcases/kernel/syscalls/prctl/prctl04.c
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2019 FUJITSU LIMITED. All rights reserved.
+ * Author: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
+ *
+ * Test PR_GET_SECCOMP and PR_SET_SECCOMP of prctl(2).
+ * 1) If PR_SET_SECCOMP sets the SECCOMP_MODE_STRICT for the calling thread,
+ * the only system call that the thread is permitted to make are read(2),
+ * write(2),_exit(2)(but not exit_group(2)), and sigreturn(2). Other
+ * system calls result in the delivery of a SIGKILL signal. This operation
+ * is available only if the kernel is configured with CONFIG_SECCOMP enabled.
+ * 2) If PR_SET_SECCOMP sets the SECCOMP_MODE_FILTER for the calling thread,
+ * the system calls allowed are defined by a pointer to a Berkeley Packet
+ * Filter. Other system calls result int the delivery of a SIGSYS signal
+ * with SECCOMP_RET_KILL. The SECCOMP_SET_MODE_FILTER operation is available
+ * only if the kernel is configured with CONFIG_SECCOMP_FILTER enabled.
+ * 3) If SECCOMP_MODE_FILTER filters permit fork(2), then the seccomp mode
+ * is inherited by children created by fork(2).
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <linux/filter.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include "tst_test.h"
+#include "lapi/syscalls.h"
+#include "lapi/prctl.h"
+#include "config.h"
+#include "lapi/seccomp.h"
+
+#define FNAME "filename"
+
+static const struct sock_filter strict_filter[] = {
+ BPF_STMT(BPF_LD | BPF_W | BPF_ABS, (offsetof (struct seccomp_data, nr))),
+
+ BPF_JUMP(BPF_JMP | BPF_JEQ, __NR_close, 5, 0),
+ BPF_JUMP(BPF_JMP | BPF_JEQ, __NR_exit, 4, 0),
+ BPF_JUMP(BPF_JMP | BPF_JEQ, __NR_wait4, 3, 0),
+ BPF_JUMP(BPF_JMP | BPF_JEQ, __NR_write, 2, 0),
+ BPF_JUMP(BPF_JMP | BPF_JEQ, __NR_clone, 1, 0),
+
+ BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_KILL),
+ BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ALLOW)
+};
+
+static const struct sock_fprog strict = {
+ .len = (unsigned short)ARRAY_SIZE(strict_filter),
+ .filter = (struct sock_filter *)strict_filter
+};
+
+static void check_strict_mode(int);
+static void check_filter_mode(int);
+
+static struct tcase {
+ void (*func_check)();
+ int pass_flag;
+ int val;
+ int exp_signal;
+ char *message;
+} tcases[] = {
+ {check_strict_mode, 1, 1, SIGKILL,
+ "SECCOMP_MODE_STRICT doesn't permit GET_SECCOMP call"},
+
+ {check_strict_mode, 0, 2, SIGKILL,
+ "SECCOMP_MODE_STRICT doesn't permit read(2) write(2) and _exit(2)"},
+
+ {check_strict_mode, 1, 3, SIGKILL,
+ "SECCOMP_MODE_STRICT doesn't permit close(2)"},
+
+ {check_filter_mode, 1, 1, SIGSYS,
+ "SECCOMP_MODE_FILTER doestn't permit GET_SECCOMP call"},
+
+ {check_filter_mode, 0, 2, SIGSYS,
+ "SECCOMP_MODE_FILTER doesn't permit close(2)"},
+
+ {check_filter_mode, 2, 3, SIGSYS,
+ "SECCOMP_MODE_FILTER doesn't permit exit()"},
+
+ {check_filter_mode, 0, 4, SIGSYS,
+ "SECCOMP_MODE_FILTER doesn't permit exit()"}
+};
+
+static void check_filter_mode_inherit(void)
+{
+ int childpid;
+ int childstatus;
+
+ childpid = SAFE_FORK();
+ if (childpid == 0) {
+ tst_res(TPASS, "SECCOMP_MODE_FILTER permits fork(2)");
+ exit(0);
+ }
+
+ wait4(childpid, &childstatus, 0, NULL);
+ if (WIFSIGNALED(childstatus) && WTERMSIG(childstatus) == SIGSYS)
+ tst_res(TPASS,
+ "SECCOMP_MODE_FILTER has been inherited by child");
+ else
+ tst_res(TFAIL,
+ "SECCOMP_MODE_FILTER isn't been inherited by child");
+}
+
+static void check_strict_mode(int val)
+{
+ int fd;
+ char buf[2];
+
+ fd = SAFE_OPEN(FNAME, O_RDWR | O_CREAT, 0666);
+
+ TEST(prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT));
+ if (TST_RET == -1) {
+ tst_res(TFAIL | TTERRNO,
+ "prctl(PR_SET_SECCOMP) sets SECCOMP_MODE_STRICT failed");
+ return;
+ }
+
+ switch (val) {
+ case 1:
+ tst_res(TPASS,
+ "prctl(PR_SET_SECCOMP) sets SECCOMP_MODE_STRICT succeed");
+ prctl(PR_GET_SECCOMP);
+ tst_res(TFAIL, "prctl(PR_GET_SECCOMP) succeed unexpectedly");
+ break;
+ case 2:
+ SAFE_WRITE(1, fd, "a", 1);
+ SAFE_READ(0, fd, buf, 1);
+ tst_res(TPASS,
+ "SECCOMP_MODE_STRICT permits read(2) write(2) and _exit(2)");
+ break;
+ case 3:
+ close(fd);
+ tst_res(TFAIL,
+ "SECCOMP_MODE_STRICT permits close(2) unexpectdly");
+ break;
+ }
+
+ tst_syscall(__NR_exit, 0);
+}
+
+static void check_filter_mode(int val)
+{
+ int fd;
+
+ fd = SAFE_OPEN(FNAME, O_RDWR | O_CREAT, 0666);
+
+ TEST(prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &strict));
+ if (TST_RET == -1) {
+ if (TST_ERR == EINVAL)
+ tst_res(TCONF,
+ "kernel doesn't support SECCOMP_MODE_FILTER");
+ else
+ tst_res(TFAIL | TERRNO,
+ "prctl(PR_SET_SECCOMP) sets SECCOMP_MODE_FILTER failed");
+ return;
+ }
+
+ switch (val) {
+ case 1:
+ tst_res(TPASS,
+ "prctl(PR_SET_SECCOMP) sets SECCOMP_MODE_FILTER succeed");
+ prctl(PR_GET_SECCOMP);
+ tst_res(TFAIL, "prctl(PR_GET_SECCOMP) succeed unexpectedly");
+ break;
+ case 2:
+ close(fd);
+ tst_res(TPASS, "SECCOMP_MODE_FILTER permits close(2)");
+ break;
+ case 3:
+ exit(0);
+ break;
+ case 4:
+ check_filter_mode_inherit();
+ break;
+ }
+
+ tst_syscall(__NR_exit, 0);
+}
+
+static void verify_prctl(unsigned int n)
+{
+ int pid;
+ int status;
+ struct tcase *tc = &tcases[n];
+
+ pid = SAFE_FORK();
+ if (pid == 0) {
+ tc->func_check(tc->val);
+ } else {
+ SAFE_WAITPID(pid, &status, 0);
+ if (WIFSIGNALED(status) && WTERMSIG(status) == tc->exp_signal) {
+ if (tc->pass_flag)
+ tst_res(TPASS, "%s", tc->message);
+ else
+ tst_res(TFAIL, "%s", tc->message);
+ return;
+ }
+
+ if (tc->pass_flag == 2)
+ tst_res(TFAIL,
+ "SECCOMP_MODE_FILTER permits exit() unexpectedly");
+ }
+}
+
+static void setup(void)
+{
+ TEST(prctl(PR_GET_SECCOMP));
+ if (TST_RET == 0) {
+ tst_res(TINFO, "kernel support PR_GET/SET_SECCOMP");
+ return;
+ }
+
+ if (TST_ERR == EINVAL)
+ tst_brk(TCONF, "kernel doesn't support PR_GET/SET_SECCOMP");
+
+ tst_brk(TBROK | TTERRNO,
+ "current environment doesn't permit PR_GET/SET_SECCOMP");
+}
+
+static struct tst_test test = {
+ .setup = setup,
+ .test = verify_prctl,
+ .tcnt = ARRAY_SIZE(tcases),
+ .forks_child = 1,
+ .needs_tmpdir = 1,
+ .needs_root = 1,
+};
--
2.18.1
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