4.14-stable review patch. If anyone has any objections, please let me know.
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From: Tycho Andersen tycho@tycho.ws
[ Upstream commit d057dc4e35e16050befa3dda943876dab39cbf80 ]
Let's test that we get the flags correctly, and that we preserve the filter index across the ptrace(PTRACE_SECCOMP_GET_METADATA) correctly.
Signed-off-by: Tycho Andersen tycho@tycho.ws CC: Kees Cook keescook@chromium.org Signed-off-by: Kees Cook keescook@chromium.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- tools/testing/selftests/seccomp/seccomp_bpf.c | 61 ++++++++++++++++++++++++++ 1 file changed, 61 insertions(+)
--- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -145,6 +145,15 @@ struct seccomp_data { #define SECCOMP_FILTER_FLAG_SPEC_ALLOW (1UL << 2) #endif
+#ifndef PTRACE_SECCOMP_GET_METADATA +#define PTRACE_SECCOMP_GET_METADATA 0x420d + +struct seccomp_metadata { + __u64 filter_off; /* Input: which filter */ + __u64 flags; /* Output: filter's flags */ +}; +#endif + #ifndef seccomp int seccomp(unsigned int op, unsigned int flags, void *args) { @@ -2861,6 +2870,58 @@ TEST(get_action_avail) EXPECT_EQ(errno, EOPNOTSUPP); }
+TEST(get_metadata) +{ + pid_t pid; + int pipefd[2]; + char buf; + struct seccomp_metadata md; + + ASSERT_EQ(0, pipe(pipefd)); + + pid = fork(); + ASSERT_GE(pid, 0); + if (pid == 0) { + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + /* one with log, one without */ + ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, + SECCOMP_FILTER_FLAG_LOG, &prog)); + ASSERT_EQ(0, seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog)); + + ASSERT_EQ(0, close(pipefd[0])); + ASSERT_EQ(1, write(pipefd[1], "1", 1)); + ASSERT_EQ(0, close(pipefd[1])); + + while (1) + sleep(100); + } + + ASSERT_EQ(0, close(pipefd[1])); + ASSERT_EQ(1, read(pipefd[0], &buf, 1)); + + ASSERT_EQ(0, ptrace(PTRACE_ATTACH, pid)); + ASSERT_EQ(pid, waitpid(pid, NULL, 0)); + + md.filter_off = 0; + ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md)); + EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG); + EXPECT_EQ(md.filter_off, 0); + + md.filter_off = 1; + ASSERT_EQ(sizeof(md), ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md)); + EXPECT_EQ(md.flags, 0); + EXPECT_EQ(md.filter_off, 1); + + ASSERT_EQ(0, kill(pid, SIGKILL)); +} + /* * TODO: * - add microbenchmarks