diff options
| author | Greg Steuck <blackgnezdo@gmail.com> | 2018-12-10 02:20:16 -0800 |
|---|---|---|
| committer | Dmitry Vyukov <dvyukov@google.com> | 2018-12-10 11:20:16 +0100 |
| commit | 6565f24da9f4eb36702339ba290213995fcc902f (patch) | |
| tree | e1e14f1299c8ce54fa8098b2226e80cdccdf1c45 /executor/common_bsd.h | |
| parent | 96cc4c50c3e0bd42e1a0ebad8539fc6734b60ecf (diff) | |
executor: add setuid sandbox for openbsd
* executor/common_bsd: add setuid sandbox
Fixes #833
cc @mptre
* Reduced duplications, resolved TODO.
Diffstat (limited to 'executor/common_bsd.h')
| -rw-r--r-- | executor/common_bsd.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/executor/common_bsd.h b/executor/common_bsd.h index 9c61917d7..53ffc8668 100644 --- a/executor/common_bsd.h +++ b/executor/common_bsd.h @@ -267,10 +267,42 @@ static long syz_extract_tcp_res(long a0, long a1, long a2) #endif #endif // GOOS_freebsd || GOOS_openbsd +#if SYZ_EXECUTOR || SYZ_SANDBOX_SETUID || SYZ_SANDBOX_NONE + +#include <sys/resource.h> +#include <unistd.h> + +static void sandbox_common() +{ + if (setsid() == -1) + fail("setsid failed"); + + // Some minimal sandboxing. + struct rlimit rlim; +#ifndef GOOS_openbsd + // Documented bug in OpenBSD. + // This causes frequent random aborts on netbsd. Reason unknown. + rlim.rlim_cur = rlim.rlim_max = 128 << 20; + setrlimit(RLIMIT_AS, &rlim); +#endif + rlim.rlim_cur = rlim.rlim_max = 8 << 20; + setrlimit(RLIMIT_MEMLOCK, &rlim); + rlim.rlim_cur = rlim.rlim_max = 1 << 20; + setrlimit(RLIMIT_FSIZE, &rlim); + rlim.rlim_cur = rlim.rlim_max = 1 << 20; + setrlimit(RLIMIT_STACK, &rlim); + rlim.rlim_cur = rlim.rlim_max = 0; + setrlimit(RLIMIT_CORE, &rlim); + rlim.rlim_cur = rlim.rlim_max = 256; // see kMaxFd + setrlimit(RLIMIT_NOFILE, &rlim); +} +#endif // SYZ_EXECUTOR || SYZ_SANDBOX_SETUID || SYZ_SANDBOX_NONE + #if SYZ_EXECUTOR || SYZ_SANDBOX_NONE static void loop(); static int do_sandbox_none(void) { + sandbox_common(); #if (GOOS_freebsd || GOOS_openbsd) && (SYZ_EXECUTOR || SYZ_TUN_ENABLE) initialize_tun(procid); #endif @@ -278,3 +310,45 @@ static int do_sandbox_none(void) return 0; } #endif // SYZ_EXECUTOR || SYZ_SANDBOX_NONE + +#if SYZ_EXECUTOR || SYZ_SANDBOX_SETUID + +#include <sys/resource.h> +#include <sys/wait.h> +#include <unistd.h> + +static int wait_for_loop(int pid) +{ + if (pid < 0) + fail("sandbox fork failed"); + debug("spawned loop pid %d\n", pid); + int status = 0; + while (waitpid(-1, &status, WUNTRACED) != pid) { + } + return WEXITSTATUS(status); +} + +#define SYZ_HAVE_SANDBOX_SETUID 1 +static int do_sandbox_setuid(void) +{ + int pid = fork(); + if (pid != 0) + return wait_for_loop(pid); + + sandbox_common(); +#if (GOOS_freebsd || GOOS_openbsd) && (SYZ_EXECUTOR || SYZ_TUN_ENABLE) + initialize_tun(procid); +#endif + + const int nobody = 65534; + if (setgroups(0, NULL)) + fail("failed to setgroups"); + if (setresgid(nobody, nobody, nobody)) + fail("failed to setresgid"); + if (setresuid(nobody, nobody, nobody)) + fail("failed to setresuid"); + + loop(); + doexit(1); +} +#endif // SYZ_EXECUTOR || SYZ_SANDBOX_SETUID |