diff options
| author | Dmitry Vyukov <dvyukov@google.com> | 2018-02-26 15:54:02 +0100 |
|---|---|---|
| committer | Dmitry Vyukov <dvyukov@google.com> | 2018-02-26 15:54:02 +0100 |
| commit | 66cf309385d0da374a6b0f14fcc87cef2cd6768f (patch) | |
| tree | 768b104a7bc49773aa3cdcd488b393ecc29c2bf9 /executor/common_linux.h | |
| parent | 14dae29c2abebd8886909c7a09c5795ffdd11515 (diff) | |
executor, pkg/csource: make fd numbers consistent
Currently when executor creates fd's it gets: 0, 3, 4.
When tun is enabled: 3, 4, 5.
For C programs: 3, 4, 5.
When run is enabled: 4, 5, 6.
Theoretically it should not matter,
but these fd numbers are probably sometimes are used as data.
So make them consistent in all these cases (3, 4, 5).
Diffstat (limited to 'executor/common_linux.h')
| -rw-r--r-- | executor/common_linux.h | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/executor/common_linux.h b/executor/common_linux.h index 1411fe8e2..f74effbba 100644 --- a/executor/common_linux.h +++ b/executor/common_linux.h @@ -309,6 +309,13 @@ static void initialize_tun(int id) return; #endif } + // Remap tun onto higher fd number to hide it from fuzzer and to keep + // fd numbers stable regardless of whether tun is opened or not. + const int kTunFd = 252; + if (dup2(tunfd, kTunFd) < 0) + fail("dup2(tunfd, kTunFd) failed"); + close(tunfd); + tunfd = kTunFd; char iface[IFNAMSIZ]; snprintf_check(iface, sizeof(iface), "syz%d", id); @@ -896,9 +903,12 @@ static int namespace_sandbox_proc(void* arg) fail("mkdir failed"); // selinux mount used to be at /selinux, but then moved to /sys/fs/selinux. const char* selinux_path = "./syz-tmp/newroot/selinux"; - if (mount("/selinux", selinux_path, NULL, mount_flags, NULL) && - mount("/sys/fs/selinux", selinux_path, NULL, mount_flags, NULL)) - fail("mount(selinuxfs) failed"); + if (mount("/selinux", selinux_path, NULL, mount_flags, NULL)) { + if (errno != ENOENT) + fail("mount(/selinux) failed"); + if (mount("/sys/fs/selinux", selinux_path, NULL, mount_flags, NULL) && errno != ENOENT) + fail("mount(/sys/fs/selinux) failed"); + } if (mkdir("./syz-tmp/pivot", 0777)) fail("mkdir failed"); if (syscall(SYS_pivot_root, "./syz-tmp", "./syz-tmp/pivot")) { |