2 1a49166d 2021-01-23 op * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
4 e29dbd72 2021-01-23 op * Permission to use, copy, modify, and distribute this software for any
5 e29dbd72 2021-01-23 op * purpose with or without fee is hereby granted, provided that the above
6 e29dbd72 2021-01-23 op * copyright notice and this permission notice appear in all copies.
8 e29dbd72 2021-01-23 op * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 e29dbd72 2021-01-23 op * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 e29dbd72 2021-01-23 op * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 e29dbd72 2021-01-23 op * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 e29dbd72 2021-01-23 op * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 e29dbd72 2021-01-23 op * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 e29dbd72 2021-01-23 op * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 dafb57b8 2021-01-15 op #include "gmid.h"
19 8bb8cf2a 2021-07-02 op #if DISABLE_SANDBOX
21 8bb8cf2a 2021-07-02 op #warning "Sandbox disabled! Please report issues upstream instead of disabling the sandbox."
24 8bb8cf2a 2021-07-02 op sandbox_server_process(void)
30 8bb8cf2a 2021-07-02 op sandbox_executor_process(void)
32 4842c72d 2021-10-18 op log_notice(NULL, "Sandbox disabled! "
33 8bb8cf2a 2021-07-02 op "Please report issues upstream instead of disabling the sandbox.");
37 8bb8cf2a 2021-07-02 op sandbox_logger_process(void)
42 8bb8cf2a 2021-07-02 op #elif defined(__FreeBSD__)
44 dafb57b8 2021-01-15 op #include <sys/capsicum.h>
47 62e001b0 2021-03-20 op sandbox_server_process(void)
49 dafb57b8 2021-01-15 op if (cap_enter() == -1)
50 8e56d6ad 2021-02-11 op fatal("cap_enter");
54 62e001b0 2021-03-20 op sandbox_executor_process(void)
57 a8a1f439 2021-07-07 op * We cannot capsicum the executor process because it needs to
58 a8a1f439 2021-07-07 op * fork(2)+execve(2) cgi scripts
64 62e001b0 2021-03-20 op sandbox_logger_process(void)
66 62e001b0 2021-03-20 op if (cap_enter() == -1)
67 62e001b0 2021-03-20 op fatal("cap_enter");
70 dafb57b8 2021-01-15 op #elif defined(__linux__)
72 0c66b6ad 2021-09-26 op #include <sys/ioctl.h>
73 71b7eb2f 2021-01-17 op #include <sys/prctl.h>
74 71b7eb2f 2021-01-17 op #include <sys/syscall.h>
75 71b7eb2f 2021-01-17 op #include <sys/syscall.h>
76 71b7eb2f 2021-01-17 op #include <sys/types.h>
78 71b7eb2f 2021-01-17 op #include <linux/audit.h>
79 71b7eb2f 2021-01-17 op #include <linux/filter.h>
80 71b7eb2f 2021-01-17 op #include <linux/seccomp.h>
82 71b7eb2f 2021-01-17 op #include <errno.h>
83 3c0375e4 2021-01-20 op #include <fcntl.h>
84 71b7eb2f 2021-01-17 op #include <stddef.h>
85 71b7eb2f 2021-01-17 op #include <stdio.h>
86 71b7eb2f 2021-01-17 op #include <string.h>
88 3499ce5a 2021-09-19 op #if HAVE_LANDLOCK
89 3499ce5a 2021-09-19 op # include "landlock_shim.h"
92 137def5f 2021-07-02 op /* uncomment to enable debugging. ONLY FOR DEVELOPMENT */
93 137def5f 2021-07-02 op /* #define SC_DEBUG */
95 137def5f 2021-07-02 op #ifdef SC_DEBUG
96 137def5f 2021-07-02 op # define SC_FAIL SECCOMP_RET_TRAP
98 137def5f 2021-07-02 op # define SC_FAIL SECCOMP_RET_KILL
101 137def5f 2021-07-02 op #if (BYTE_ORDER == LITTLE_ENDIAN)
102 137def5f 2021-07-02 op # define SC_ARG_LO 0
103 137def5f 2021-07-02 op # define SC_ARG_HI sizeof(uint32_t)
104 137def5f 2021-07-02 op #elif (BYTE_ORDER == BIG_ENDIAN)
105 137def5f 2021-07-02 op # define SC_ARG_LO sizeof(uint32_t)
106 137def5f 2021-07-02 op # define SC_ARG_HI 0
108 137def5f 2021-07-02 op # error "Uknown endian"
111 137def5f 2021-07-02 op /* make the filter more readable */
112 137def5f 2021-07-02 op #define SC_ALLOW(nr) \
113 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, __NR_##nr, 0, 1), \
114 137def5f 2021-07-02 op BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ALLOW)
117 137def5f 2021-07-02 op * SC_ALLOW_ARG and the SECCOMP_AUDIT_ARCH below are courtesy of
118 137def5f 2021-07-02 op * https://roy.marples.name/git/dhcpcd/blob/HEAD:/src/privsep-linux.c
120 137def5f 2021-07-02 op #define SC_ALLOW_ARG(_nr, _arg, _val) \
121 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, (_nr), 0, 6), \
122 137def5f 2021-07-02 op BPF_STMT(BPF_LD + BPF_W + BPF_ABS, \
123 137def5f 2021-07-02 op offsetof(struct seccomp_data, args[(_arg)]) + SC_ARG_LO), \
124 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, \
125 137def5f 2021-07-02 op ((_val) & 0xffffffff), 0, 3), \
126 137def5f 2021-07-02 op BPF_STMT(BPF_LD + BPF_W + BPF_ABS, \
127 137def5f 2021-07-02 op offsetof(struct seccomp_data, args[(_arg)]) + SC_ARG_HI), \
128 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, \
129 137def5f 2021-07-02 op (((uint32_t)((uint64_t)(_val) >> 32)) & 0xffffffff), 0, 1), \
130 137def5f 2021-07-02 op BPF_STMT(BPF_RET + BPF_K, SECCOMP_RET_ALLOW), \
131 137def5f 2021-07-02 op BPF_STMT(BPF_LD + BPF_W + BPF_ABS, \
132 137def5f 2021-07-02 op offsetof(struct seccomp_data, nr))
135 137def5f 2021-07-02 op * I personally find this quite nutty. Why can a system header not
136 137def5f 2021-07-02 op * define a default for this?
138 71b7eb2f 2021-01-17 op #if defined(__i386__)
139 71b7eb2f 2021-01-17 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_I386
140 71b7eb2f 2021-01-17 op #elif defined(__x86_64__)
141 71b7eb2f 2021-01-17 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_X86_64
142 137def5f 2021-07-02 op #elif defined(__arc__)
143 137def5f 2021-07-02 op # if defined(__A7__)
144 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
145 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARCOMPACT
147 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARCOMPACTBE
149 137def5f 2021-07-02 op # elif defined(__HS__)
150 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
151 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARCV2
153 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARCV2BE
156 137def5f 2021-07-02 op # error "Platform does not support seccomp filter yet"
158 71b7eb2f 2021-01-17 op #elif defined(__arm__)
159 137def5f 2021-07-02 op # ifndef EM_ARM
160 137def5f 2021-07-02 op # define EM_ARM 40
162 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
163 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARM
165 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARMEB
167 71b7eb2f 2021-01-17 op #elif defined(__aarch64__)
168 71b7eb2f 2021-01-17 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_AARCH64
169 137def5f 2021-07-02 op #elif defined(__alpha__)
170 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ALPHA
171 137def5f 2021-07-02 op #elif defined(__hppa__)
172 137def5f 2021-07-02 op # if defined(__LP64__)
173 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PARISC64
175 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PARISC
177 137def5f 2021-07-02 op #elif defined(__ia64__)
178 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_IA64
179 137def5f 2021-07-02 op #elif defined(__microblaze__)
180 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MICROBLAZE
181 137def5f 2021-07-02 op #elif defined(__m68k__)
182 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_M68K
183 71b7eb2f 2021-01-17 op #elif defined(__mips__)
184 137def5f 2021-07-02 op # if defined(__MIPSEL__)
185 137def5f 2021-07-02 op # if defined(__LP64__)
186 71b7eb2f 2021-01-17 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPSEL64
188 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPSEL
190 137def5f 2021-07-02 op # elif defined(__LP64__)
191 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPS64
193 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPS
195 137def5f 2021-07-02 op #elif defined(__nds32__)
196 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
197 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_NDS32
199 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_NDS32BE
201 137def5f 2021-07-02 op #elif defined(__nios2__)
202 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_NIOS2
203 137def5f 2021-07-02 op #elif defined(__or1k__)
204 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_OPENRISC
205 137def5f 2021-07-02 op #elif defined(__powerpc64__)
206 b24021d4 2021-07-03 op # if (BYTE_ORDER == LITTLE_ENDIAN)
207 b24021d4 2021-07-03 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PPC64LE
209 b24021d4 2021-07-03 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PPC64
211 137def5f 2021-07-02 op #elif defined(__powerpc__)
212 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PPC
213 137def5f 2021-07-02 op #elif defined(__riscv)
214 137def5f 2021-07-02 op # if defined(__LP64__)
215 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_RISCV64
217 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_RISCV32
219 137def5f 2021-07-02 op #elif defined(__s390x__)
220 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_S390X
221 137def5f 2021-07-02 op #elif defined(__s390__)
222 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_S390
223 137def5f 2021-07-02 op #elif defined(__sh__)
224 137def5f 2021-07-02 op # if defined(__LP64__)
225 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
226 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SHEL64
228 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SH64
231 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
232 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SHEL
234 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SH
237 137def5f 2021-07-02 op #elif defined(__sparc__)
238 137def5f 2021-07-02 op # if defined(__arch64__)
239 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SPARC64
241 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SPARC
243 137def5f 2021-07-02 op #elif defined(__xtensa__)
244 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_XTENSA
246 71b7eb2f 2021-01-17 op # error "Platform does not support seccomp filter yet"
249 e5d82d94 2022-03-19 op static const struct sock_filter filter[] = {
250 137def5f 2021-07-02 op /* load the *current* architecture */
251 137def5f 2021-07-02 op BPF_STMT(BPF_LD | BPF_W | BPF_ABS,
252 137def5f 2021-07-02 op (offsetof(struct seccomp_data, arch))),
253 137def5f 2021-07-02 op /* ensure it's the same that we've been compiled on */
254 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K,
255 137def5f 2021-07-02 op SECCOMP_AUDIT_ARCH, 1, 0),
256 137def5f 2021-07-02 op /* if not, kill the program */
257 137def5f 2021-07-02 op BPF_STMT(BPF_RET | BPF_K, SC_FAIL),
259 137def5f 2021-07-02 op /* load the syscall number */
260 137def5f 2021-07-02 op BPF_STMT(BPF_LD | BPF_W | BPF_ABS,
261 137def5f 2021-07-02 op (offsetof(struct seccomp_data, nr))),
263 137def5f 2021-07-02 op #ifdef __NR_accept
264 137def5f 2021-07-02 op SC_ALLOW(accept),
266 137def5f 2021-07-02 op #ifdef __NR_accept4
267 137def5f 2021-07-02 op SC_ALLOW(accept4),
269 137def5f 2021-07-02 op #ifdef __NR_brk
270 137def5f 2021-07-02 op SC_ALLOW(brk),
272 137def5f 2021-07-02 op #ifdef __NR_clock_gettime
273 137def5f 2021-07-02 op SC_ALLOW(clock_gettime),
275 137def5f 2021-07-02 op #if defined(__x86_64__) && defined(__ILP32__) && defined(__X32_SYSCALL_BIT)
276 137def5f 2021-07-02 op SECCOMP_ALLOW(__NR_clock_gettime & ~__X32_SYSCALL_BIT),
278 137def5f 2021-07-02 op #ifdef __NR_clock_gettime64
279 137def5f 2021-07-02 op SC_ALLOW(clock_gettime64),
281 137def5f 2021-07-02 op #ifdef __NR_close
282 137def5f 2021-07-02 op SC_ALLOW(close),
284 137def5f 2021-07-02 op #ifdef __NR_epoll_ctl
285 137def5f 2021-07-02 op SC_ALLOW(epoll_ctl),
287 137def5f 2021-07-02 op #ifdef __NR_epoll_pwait
288 137def5f 2021-07-02 op SC_ALLOW(epoll_pwait),
290 137def5f 2021-07-02 op #ifdef __NR_epoll_wait
291 137def5f 2021-07-02 op SC_ALLOW(epoll_wait),
293 137def5f 2021-07-02 op #ifdef __NR_exit
294 137def5f 2021-07-02 op SC_ALLOW(exit),
296 137def5f 2021-07-02 op #ifdef __NR_exit_group
297 137def5f 2021-07-02 op SC_ALLOW(exit_group),
299 137def5f 2021-07-02 op #ifdef __NR_fcntl
300 137def5f 2021-07-02 op SC_ALLOW(fcntl),
302 137def5f 2021-07-02 op #ifdef __NR_fcntl64
303 137def5f 2021-07-02 op SC_ALLOW(fcntl64),
305 137def5f 2021-07-02 op #ifdef __NR_fstat
306 137def5f 2021-07-02 op SC_ALLOW(fstat),
308 21f7d246 2021-07-23 op #ifdef __NR_fstat64
309 21f7d246 2021-07-23 op SC_ALLOW(fstat64),
311 94c5f99a 2022-02-13 op #ifdef __NR_fstatat64
312 94c5f99a 2022-02-13 op SC_ALLOW(fstatat64),
314 137def5f 2021-07-02 op #ifdef __NR_getdents64
315 137def5f 2021-07-02 op SC_ALLOW(getdents64),
317 137def5f 2021-07-02 op #ifdef __NR_getpid
318 137def5f 2021-07-02 op SC_ALLOW(getpid),
320 137def5f 2021-07-02 op #ifdef __NR_getrandom
321 137def5f 2021-07-02 op SC_ALLOW(getrandom),
323 137def5f 2021-07-02 op #ifdef __NR_gettimeofday
324 137def5f 2021-07-02 op SC_ALLOW(gettimeofday),
326 137def5f 2021-07-02 op #ifdef __NR_ioctl
327 6f27d259 2021-09-26 op /* allow ioctl on fd 1, glibc doing stuff? */
328 4842c72d 2021-10-18 op SC_ALLOW_ARG(__NR_ioctl, 0, 1),
329 6f27d259 2021-09-26 op /* allow FIONREAD needed by libevent */
330 6f27d259 2021-09-26 op SC_ALLOW_ARG(__NR_ioctl, 1, FIONREAD),
332 94c5f99a 2022-02-13 op #ifdef __NR__llseek
333 94c5f99a 2022-02-13 op SC_ALLOW(_llseek),
335 137def5f 2021-07-02 op #ifdef __NR_lseek
336 137def5f 2021-07-02 op SC_ALLOW(lseek),
338 137def5f 2021-07-02 op #ifdef __NR_madvise
339 137def5f 2021-07-02 op SC_ALLOW(madvise),
341 137def5f 2021-07-02 op #ifdef __NR_mmap
342 137def5f 2021-07-02 op SC_ALLOW(mmap),
344 137def5f 2021-07-02 op #ifdef __NR_mmap2
345 137def5f 2021-07-02 op SC_ALLOW(mmap2),
347 137def5f 2021-07-02 op #ifdef __NR_munmap
348 137def5f 2021-07-02 op SC_ALLOW(munmap),
350 137def5f 2021-07-02 op #ifdef __NR_newfstatat
351 137def5f 2021-07-02 op SC_ALLOW(newfstatat),
353 137def5f 2021-07-02 op #ifdef __NR_oldfstat
354 137def5f 2021-07-02 op SC_ALLOW(oldfstat),
356 137def5f 2021-07-02 op #ifdef __NR_openat
357 4f0e893c 2022-02-13 op SC_ALLOW_ARG(__NR_openat, 3, O_RDONLY),
359 137def5f 2021-07-02 op #ifdef __NR_prlimit64
360 137def5f 2021-07-02 op SC_ALLOW(prlimit64),
362 137def5f 2021-07-02 op #ifdef __NR_read
363 137def5f 2021-07-02 op SC_ALLOW(read),
365 137def5f 2021-07-02 op #ifdef __NR_recvmsg
366 137def5f 2021-07-02 op SC_ALLOW(recvmsg),
368 a8e1e8d7 2021-07-23 op #ifdef __NR_readv
369 a8e1e8d7 2021-07-23 op SC_ALLOW(readv),
371 137def5f 2021-07-02 op #ifdef __NR_rt_sigaction
372 137def5f 2021-07-02 op SC_ALLOW(rt_sigaction),
374 137def5f 2021-07-02 op #ifdef __NR_rt_sigreturn
375 137def5f 2021-07-02 op SC_ALLOW(rt_sigreturn),
377 137def5f 2021-07-02 op #ifdef __NR_sendmsg
378 137def5f 2021-07-02 op SC_ALLOW(sendmsg),
380 94c5f99a 2022-02-13 op #ifdef __NR_sigreturn
381 94c5f99a 2022-02-13 op SC_ALLOW(sigreturn),
383 137def5f 2021-07-02 op #ifdef __NR_statx
384 137def5f 2021-07-02 op SC_ALLOW(statx),
386 63bf54b6 2021-12-11 vdrummer #ifdef __NR_ugetrlimit
387 63bf54b6 2021-12-11 vdrummer SC_ALLOW(ugetrlimit),
389 137def5f 2021-07-02 op #ifdef __NR_write
390 137def5f 2021-07-02 op SC_ALLOW(write),
392 137def5f 2021-07-02 op #ifdef __NR_writev
393 137def5f 2021-07-02 op SC_ALLOW(writev),
396 4aa1dd55 2021-07-03 op /* disallow everything else */
397 137def5f 2021-07-02 op BPF_STMT(BPF_RET | BPF_K, SC_FAIL),
400 71b7eb2f 2021-01-17 op #ifdef SC_DEBUG
402 71b7eb2f 2021-01-17 op #include <signal.h>
403 71b7eb2f 2021-01-17 op #include <unistd.h>
406 71b7eb2f 2021-01-17 op sandbox_seccomp_violation(int signum, siginfo_t *info, void *ctx)
408 71b7eb2f 2021-01-17 op fprintf(stderr, "%s: unexpected system call (arch:0x%x,syscall:%d @ %p)\n",
409 71b7eb2f 2021-01-17 op __func__, info->si_arch, info->si_syscall, info->si_call_addr);
414 71b7eb2f 2021-01-17 op sandbox_seccomp_catch_sigsys(void)
416 71b7eb2f 2021-01-17 op struct sigaction act;
417 71b7eb2f 2021-01-17 op sigset_t mask;
419 71b7eb2f 2021-01-17 op memset(&act, 0, sizeof(act));
420 71b7eb2f 2021-01-17 op sigemptyset(&mask);
421 71b7eb2f 2021-01-17 op sigaddset(&mask, SIGSYS);
423 71b7eb2f 2021-01-17 op act.sa_sigaction = &sandbox_seccomp_violation;
424 71b7eb2f 2021-01-17 op act.sa_flags = SA_SIGINFO;
425 8e56d6ad 2021-02-11 op if (sigaction(SIGSYS, &act, NULL) == -1)
426 8e56d6ad 2021-02-11 op fatal("%s: sigaction(SIGSYS): %s",
427 71b7eb2f 2021-01-17 op __func__, strerror(errno));
429 8e56d6ad 2021-02-11 op if (sigprocmask(SIG_UNBLOCK, &mask, NULL) == -1)
430 8e56d6ad 2021-02-11 op fatal("%s: sigprocmask(SIGSYS): %s\n",
431 71b7eb2f 2021-01-17 op __func__, strerror(errno));
433 71b7eb2f 2021-01-17 op #endif /* SC_DEBUG */
435 3499ce5a 2021-09-19 op #if HAVE_LANDLOCK
436 0ea22af2 2021-09-19 op static inline int
437 cb28978f 2021-09-25 op open_landlock(void)
441 e5d82d94 2022-03-19 op const struct landlock_ruleset_attr attr = {
442 98c6f8de 2022-02-10 op .handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE |
443 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_READ_FILE |
444 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_READ_DIR |
445 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_WRITE_FILE |
446 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_REMOVE_DIR |
447 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_REMOVE_FILE |
448 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_CHAR |
449 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_DIR |
450 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_REG |
451 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_SOCK |
452 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_FIFO |
453 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_BLOCK |
454 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_SYM,
457 cb28978f 2021-09-25 op fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
458 0ea22af2 2021-09-19 op if (fd == -1) {
459 0ea22af2 2021-09-19 op switch (errno) {
461 0ea22af2 2021-09-19 op fatal("%s: failed to create ruleset. "
462 0ea22af2 2021-09-19 op "Landlock doesn't seem to be supported by the "
463 0ea22af2 2021-09-19 op "current kernel.", __func__);
464 0ea22af2 2021-09-19 op case EOPNOTSUPP:
465 0ea22af2 2021-09-19 op log_warn(NULL, "%s: failed to create ruleset. "
466 0ea22af2 2021-09-19 op "Landlock seems to be currently disabled; "
467 0ea22af2 2021-09-19 op "continuing without it.", __func__);
470 0ea22af2 2021-09-19 op fatal("%s: failed to create ruleset: %s",
471 0ea22af2 2021-09-19 op __func__, strerror(errno));
479 cb28978f 2021-09-25 op landlock_unveil_path(int landlock_fd, const char *path, int perms)
481 cb28978f 2021-09-25 op struct landlock_path_beneath_attr pb;
482 cb28978f 2021-09-25 op int err, saved_errno;
484 cb28978f 2021-09-25 op pb.allowed_access = perms;
486 cb28978f 2021-09-25 op if ((pb.parent_fd = open(path, O_PATH)) == -1)
489 cb28978f 2021-09-25 op err = landlock_add_rule(landlock_fd, LANDLOCK_RULE_PATH_BENEATH,
491 cb28978f 2021-09-25 op saved_errno = errno;
492 cb28978f 2021-09-25 op close(pb.parent_fd);
493 cb28978f 2021-09-25 op errno = saved_errno;
494 cb28978f 2021-09-25 op return err ? -1 : 0;
498 cb28978f 2021-09-25 op landlock_apply(int fd)
500 cb28978f 2021-09-25 op int r, saved_errno;
502 cb28978f 2021-09-25 op if (fd == -1)
505 cb28978f 2021-09-25 op r = landlock_restrict_self(fd, 0);
506 cb28978f 2021-09-25 op saved_errno = errno;
508 cb28978f 2021-09-25 op errno = saved_errno;
509 cb28978f 2021-09-25 op return r ? -1 : 0;
513 3499ce5a 2021-09-19 op server_landlock(void)
515 cb28978f 2021-09-25 op int fd, perms;
516 3499ce5a 2021-09-19 op struct vhost *h;
517 3499ce5a 2021-09-19 op struct location *l;
520 3499ce5a 2021-09-19 op * These are all the actions allowed for the root directories
521 cb28978f 2021-09-25 op * of the vhosts.
523 cb28978f 2021-09-25 op perms = LANDLOCK_ACCESS_FS_READ_FILE | LANDLOCK_ACCESS_FS_READ_DIR;
525 cb28978f 2021-09-25 op if ((fd = open_landlock()) == -1)
528 3499ce5a 2021-09-19 op TAILQ_FOREACH(h, &hosts, vhosts) {
529 3499ce5a 2021-09-19 op TAILQ_FOREACH(l, &h->locations, locations) {
530 3499ce5a 2021-09-19 op if (l->dir == NULL)
533 cb28978f 2021-09-25 op if (landlock_unveil_path(fd, l->dir, perms) == -1)
534 cb28978f 2021-09-25 op fatal("%s: landlock_unveil_path(%s): %s",
535 3499ce5a 2021-09-19 op __func__, l->dir, strerror(errno));
539 cb28978f 2021-09-25 op return landlock_apply(fd);
543 b0be0653 2021-09-19 op logger_landlock(void)
547 cb28978f 2021-09-25 op if ((fd = open_landlock()) == -1)
550 cb28978f 2021-09-25 op /* no rules. the logger doesn't need fs access at all. */
552 cb28978f 2021-09-25 op return landlock_apply(fd);
557 62e001b0 2021-03-20 op sandbox_server_process(void)
559 e5d82d94 2022-03-19 op const struct sock_fprog prog = {
560 71b7eb2f 2021-01-17 op .len = (unsigned short) (sizeof(filter) / sizeof(filter[0])),
561 71b7eb2f 2021-01-17 op .filter = filter,
564 71b7eb2f 2021-01-17 op #ifdef SC_DEBUG
565 71b7eb2f 2021-01-17 op sandbox_seccomp_catch_sigsys();
568 8e56d6ad 2021-02-11 op if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == -1)
569 8e56d6ad 2021-02-11 op fatal("%s: prctl(PR_SET_NO_NEW_PRIVS): %s",
570 71b7eb2f 2021-01-17 op __func__, strerror(errno));
572 3499ce5a 2021-09-19 op #if HAVE_LANDLOCK
573 cb28978f 2021-09-25 op if (server_landlock() == -1)
574 cb28978f 2021-09-25 op fatal("%s: server_landlock: %s",
575 cb28978f 2021-09-25 op __func__, strerror(errno));
578 8e56d6ad 2021-02-11 op if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog) == -1)
579 8e56d6ad 2021-02-11 op fatal("%s: prctl(PR_SET_SECCOMP): %s\n",
580 71b7eb2f 2021-01-17 op __func__, strerror(errno));
584 62e001b0 2021-03-20 op sandbox_executor_process(void)
587 a8a1f439 2021-07-07 op * We cannot use seccomp for the executor process because we
588 62e001b0 2021-03-20 op * don't know what the child will do. Also, our filter will
589 62e001b0 2021-03-20 op * be inherited so the child cannot set its own seccomp
596 62e001b0 2021-03-20 op sandbox_logger_process(void)
599 b0be0653 2021-09-19 op * Here we could use a seccomp filter to allow only recvfd,
600 b0be0653 2021-09-19 op * write/writev and memory allocations, but syslog is a beast
601 b0be0653 2021-09-19 op * and I don't know what syscalls it could end up doing.
602 b0be0653 2021-09-19 op * Landlock is a simpler beast, use it to disallow any file
603 b0be0653 2021-09-19 op * sytsem access.
606 f7ee7990 2021-10-02 op if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == -1)
607 f7ee7990 2021-10-02 op fatal("%s: prctl(PR_SET_NO_NEW_PRIVS): %s",
608 f7ee7990 2021-10-02 op __func__, strerror(errno));
610 b0be0653 2021-09-19 op #if HAVE_LANDLOCK
611 cb28978f 2021-09-25 op if (logger_landlock() == -1)
612 cb28978f 2021-09-25 op fatal("%s: logger_landlock: %s",
613 b0be0653 2021-09-19 op __func__, strerror(errno));
619 dafb57b8 2021-01-15 op #elif defined(__OpenBSD__)
621 dafb57b8 2021-01-15 op #include <unistd.h>
624 62e001b0 2021-03-20 op sandbox_server_process(void)
626 fdea6aa0 2021-04-30 op struct vhost *h;
627 fdea6aa0 2021-04-30 op struct location *l;
629 b8e64ccd 2021-03-31 op TAILQ_FOREACH(h, &hosts, vhosts) {
630 fdea6aa0 2021-04-30 op TAILQ_FOREACH(l, &h->locations, locations) {
631 fdea6aa0 2021-04-30 op if (l->dir == NULL)
634 fdea6aa0 2021-04-30 op if (unveil(l->dir, "r") == -1)
635 fdea6aa0 2021-04-30 op fatal("unveil %s for domain %s",
641 881a9dd9 2021-01-16 op if (pledge("stdio recvfd rpath inet", NULL) == -1)
642 8e56d6ad 2021-02-11 op fatal("pledge");
646 62e001b0 2021-03-20 op sandbox_executor_process(void)
648 b8e64ccd 2021-03-31 op struct vhost *h;
649 fdea6aa0 2021-04-30 op struct location *l;
650 8ad1c570 2021-05-09 op struct fcgi *f;
653 b8e64ccd 2021-03-31 op TAILQ_FOREACH(h, &hosts, vhosts) {
654 fdea6aa0 2021-04-30 op TAILQ_FOREACH(l, &h->locations, locations) {
655 fdea6aa0 2021-04-30 op if (l->dir == NULL)
658 a5d822e5 2021-07-09 op /* r so we can chdir into the directory */
659 fdea6aa0 2021-04-30 op if (unveil(l->dir, "rx") == -1)
660 fdea6aa0 2021-04-30 op fatal("unveil %s for domain %s",
661 fdea6aa0 2021-04-30 op l->dir, h->domain);
665 8ad1c570 2021-05-09 op for (i = 0; i < FCGI_MAX; i++) {
666 4842c72d 2021-10-18 op f = &fcgi[i];
667 8ad1c570 2021-05-09 op if (f->path != NULL) {
668 8ad1c570 2021-05-09 op if (unveil(f->path, "rw") == -1)
669 8ad1c570 2021-05-09 op fatal("unveil %s", f->path);
672 8ad1c570 2021-05-09 op if (f->prog != NULL) {
673 8ad1c570 2021-05-09 op if (unveil(f->prog, "rx") == -1)
674 8ad1c570 2021-05-09 op fatal("unveil %s", f->prog);
679 8ad1c570 2021-05-09 op * rpath: to chdir into the correct directory
680 8ad1c570 2021-05-09 op * proc exec: CGI
681 8ad1c570 2021-05-09 op * dns inet unix: FastCGI
683 8ad1c570 2021-05-09 op if (pledge("stdio rpath sendfd proc exec dns inet unix", NULL))
684 62e001b0 2021-03-20 op err(1, "pledge");
688 62e001b0 2021-03-20 op sandbox_logger_process(void)
690 e952c505 2021-06-15 op if (pledge("stdio recvfd", NULL) == -1)
691 62e001b0 2021-03-20 op err(1, "pledge");
696 62e001b0 2021-03-20 op #warning "No sandbox method known for this OS"
699 62e001b0 2021-03-20 op sandbox_server_process(void)
705 62e001b0 2021-03-20 op sandbox_executor_process(void)
707 2a911637 2021-02-11 op log_notice(NULL, "no sandbox method known for this OS");
711 62e001b0 2021-03-20 op sandbox_logger_process(void)