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_logger_process(void)
35 8bb8cf2a 2021-07-02 op #elif defined(__FreeBSD__)
37 dafb57b8 2021-01-15 op #include <sys/capsicum.h>
40 62e001b0 2021-03-20 op sandbox_server_process(void)
42 dafb57b8 2021-01-15 op if (cap_enter() == -1)
43 8e56d6ad 2021-02-11 op fatal("cap_enter");
47 62e001b0 2021-03-20 op sandbox_logger_process(void)
49 62e001b0 2021-03-20 op if (cap_enter() == -1)
50 62e001b0 2021-03-20 op fatal("cap_enter");
53 dafb57b8 2021-01-15 op #elif defined(__linux__)
55 0c66b6ad 2021-09-26 op #include <sys/ioctl.h>
56 71b7eb2f 2021-01-17 op #include <sys/prctl.h>
57 71b7eb2f 2021-01-17 op #include <sys/syscall.h>
58 71b7eb2f 2021-01-17 op #include <sys/syscall.h>
59 71b7eb2f 2021-01-17 op #include <sys/types.h>
61 71b7eb2f 2021-01-17 op #include <linux/audit.h>
62 71b7eb2f 2021-01-17 op #include <linux/filter.h>
63 71b7eb2f 2021-01-17 op #include <linux/seccomp.h>
65 71b7eb2f 2021-01-17 op #include <errno.h>
66 3c0375e4 2021-01-20 op #include <fcntl.h>
67 71b7eb2f 2021-01-17 op #include <stddef.h>
68 71b7eb2f 2021-01-17 op #include <stdio.h>
69 71b7eb2f 2021-01-17 op #include <string.h>
71 3499ce5a 2021-09-19 op #if HAVE_LANDLOCK
72 3499ce5a 2021-09-19 op # include "landlock_shim.h"
75 137def5f 2021-07-02 op /* uncomment to enable debugging. ONLY FOR DEVELOPMENT */
76 137def5f 2021-07-02 op /* #define SC_DEBUG */
78 137def5f 2021-07-02 op #ifdef SC_DEBUG
79 137def5f 2021-07-02 op # define SC_FAIL SECCOMP_RET_TRAP
81 137def5f 2021-07-02 op # define SC_FAIL SECCOMP_RET_KILL
84 137def5f 2021-07-02 op #if (BYTE_ORDER == LITTLE_ENDIAN)
85 137def5f 2021-07-02 op # define SC_ARG_LO 0
86 137def5f 2021-07-02 op # define SC_ARG_HI sizeof(uint32_t)
87 137def5f 2021-07-02 op #elif (BYTE_ORDER == BIG_ENDIAN)
88 137def5f 2021-07-02 op # define SC_ARG_LO sizeof(uint32_t)
89 137def5f 2021-07-02 op # define SC_ARG_HI 0
91 137def5f 2021-07-02 op # error "Uknown endian"
94 137def5f 2021-07-02 op /* make the filter more readable */
95 137def5f 2021-07-02 op #define SC_ALLOW(nr) \
96 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, __NR_##nr, 0, 1), \
97 137def5f 2021-07-02 op BPF_STMT(BPF_RET | BPF_K, SECCOMP_RET_ALLOW)
100 137def5f 2021-07-02 op * SC_ALLOW_ARG and the SECCOMP_AUDIT_ARCH below are courtesy of
101 137def5f 2021-07-02 op * https://roy.marples.name/git/dhcpcd/blob/HEAD:/src/privsep-linux.c
103 137def5f 2021-07-02 op #define SC_ALLOW_ARG(_nr, _arg, _val) \
104 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, (_nr), 0, 6), \
105 137def5f 2021-07-02 op BPF_STMT(BPF_LD + BPF_W + BPF_ABS, \
106 137def5f 2021-07-02 op offsetof(struct seccomp_data, args[(_arg)]) + SC_ARG_LO), \
107 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, \
108 137def5f 2021-07-02 op ((_val) & 0xffffffff), 0, 3), \
109 137def5f 2021-07-02 op BPF_STMT(BPF_LD + BPF_W + BPF_ABS, \
110 137def5f 2021-07-02 op offsetof(struct seccomp_data, args[(_arg)]) + SC_ARG_HI), \
111 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, \
112 137def5f 2021-07-02 op (((uint32_t)((uint64_t)(_val) >> 32)) & 0xffffffff), 0, 1), \
113 137def5f 2021-07-02 op BPF_STMT(BPF_RET + BPF_K, SECCOMP_RET_ALLOW), \
114 137def5f 2021-07-02 op BPF_STMT(BPF_LD + BPF_W + BPF_ABS, \
115 137def5f 2021-07-02 op offsetof(struct seccomp_data, nr))
118 137def5f 2021-07-02 op * I personally find this quite nutty. Why can a system header not
119 137def5f 2021-07-02 op * define a default for this?
121 71b7eb2f 2021-01-17 op #if defined(__i386__)
122 71b7eb2f 2021-01-17 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_I386
123 71b7eb2f 2021-01-17 op #elif defined(__x86_64__)
124 71b7eb2f 2021-01-17 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_X86_64
125 137def5f 2021-07-02 op #elif defined(__arc__)
126 137def5f 2021-07-02 op # if defined(__A7__)
127 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
128 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARCOMPACT
130 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARCOMPACTBE
132 137def5f 2021-07-02 op # elif defined(__HS__)
133 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
134 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARCV2
136 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARCV2BE
139 137def5f 2021-07-02 op # error "Platform does not support seccomp filter yet"
141 71b7eb2f 2021-01-17 op #elif defined(__arm__)
142 137def5f 2021-07-02 op # ifndef EM_ARM
143 137def5f 2021-07-02 op # define EM_ARM 40
145 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
146 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARM
148 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ARMEB
150 71b7eb2f 2021-01-17 op #elif defined(__aarch64__)
151 71b7eb2f 2021-01-17 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_AARCH64
152 137def5f 2021-07-02 op #elif defined(__alpha__)
153 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_ALPHA
154 137def5f 2021-07-02 op #elif defined(__hppa__)
155 137def5f 2021-07-02 op # if defined(__LP64__)
156 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PARISC64
158 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PARISC
160 137def5f 2021-07-02 op #elif defined(__ia64__)
161 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_IA64
162 137def5f 2021-07-02 op #elif defined(__microblaze__)
163 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MICROBLAZE
164 137def5f 2021-07-02 op #elif defined(__m68k__)
165 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_M68K
166 71b7eb2f 2021-01-17 op #elif defined(__mips__)
167 137def5f 2021-07-02 op # if defined(__MIPSEL__)
168 137def5f 2021-07-02 op # if defined(__LP64__)
169 71b7eb2f 2021-01-17 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPSEL64
171 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPSEL
173 137def5f 2021-07-02 op # elif defined(__LP64__)
174 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPS64
176 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_MIPS
178 137def5f 2021-07-02 op #elif defined(__nds32__)
179 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
180 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_NDS32
182 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_NDS32BE
184 137def5f 2021-07-02 op #elif defined(__nios2__)
185 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_NIOS2
186 137def5f 2021-07-02 op #elif defined(__or1k__)
187 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_OPENRISC
188 137def5f 2021-07-02 op #elif defined(__powerpc64__)
189 b24021d4 2021-07-03 op # if (BYTE_ORDER == LITTLE_ENDIAN)
190 b24021d4 2021-07-03 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PPC64LE
192 b24021d4 2021-07-03 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PPC64
194 137def5f 2021-07-02 op #elif defined(__powerpc__)
195 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_PPC
196 137def5f 2021-07-02 op #elif defined(__riscv)
197 137def5f 2021-07-02 op # if defined(__LP64__)
198 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_RISCV64
200 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_RISCV32
202 137def5f 2021-07-02 op #elif defined(__s390x__)
203 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_S390X
204 137def5f 2021-07-02 op #elif defined(__s390__)
205 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_S390
206 137def5f 2021-07-02 op #elif defined(__sh__)
207 137def5f 2021-07-02 op # if defined(__LP64__)
208 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
209 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SHEL64
211 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SH64
214 137def5f 2021-07-02 op # if (BYTE_ORDER == LITTLE_ENDIAN)
215 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SHEL
217 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SH
220 137def5f 2021-07-02 op #elif defined(__sparc__)
221 137def5f 2021-07-02 op # if defined(__arch64__)
222 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SPARC64
224 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_SPARC
226 137def5f 2021-07-02 op #elif defined(__xtensa__)
227 137def5f 2021-07-02 op # define SECCOMP_AUDIT_ARCH AUDIT_ARCH_XTENSA
229 71b7eb2f 2021-01-17 op # error "Platform does not support seccomp filter yet"
232 e5d82d94 2022-03-19 op static const struct sock_filter filter[] = {
233 137def5f 2021-07-02 op /* load the *current* architecture */
234 137def5f 2021-07-02 op BPF_STMT(BPF_LD | BPF_W | BPF_ABS,
235 137def5f 2021-07-02 op (offsetof(struct seccomp_data, arch))),
236 137def5f 2021-07-02 op /* ensure it's the same that we've been compiled on */
237 137def5f 2021-07-02 op BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K,
238 137def5f 2021-07-02 op SECCOMP_AUDIT_ARCH, 1, 0),
239 137def5f 2021-07-02 op /* if not, kill the program */
240 137def5f 2021-07-02 op BPF_STMT(BPF_RET | BPF_K, SC_FAIL),
242 137def5f 2021-07-02 op /* load the syscall number */
243 137def5f 2021-07-02 op BPF_STMT(BPF_LD | BPF_W | BPF_ABS,
244 137def5f 2021-07-02 op (offsetof(struct seccomp_data, nr))),
246 137def5f 2021-07-02 op #ifdef __NR_accept
247 137def5f 2021-07-02 op SC_ALLOW(accept),
249 137def5f 2021-07-02 op #ifdef __NR_accept4
250 137def5f 2021-07-02 op SC_ALLOW(accept4),
252 137def5f 2021-07-02 op #ifdef __NR_brk
253 137def5f 2021-07-02 op SC_ALLOW(brk),
255 137def5f 2021-07-02 op #ifdef __NR_clock_gettime
256 137def5f 2021-07-02 op SC_ALLOW(clock_gettime),
258 137def5f 2021-07-02 op #if defined(__x86_64__) && defined(__ILP32__) && defined(__X32_SYSCALL_BIT)
259 137def5f 2021-07-02 op SECCOMP_ALLOW(__NR_clock_gettime & ~__X32_SYSCALL_BIT),
261 137def5f 2021-07-02 op #ifdef __NR_clock_gettime64
262 137def5f 2021-07-02 op SC_ALLOW(clock_gettime64),
264 137def5f 2021-07-02 op #ifdef __NR_close
265 137def5f 2021-07-02 op SC_ALLOW(close),
267 137def5f 2021-07-02 op #ifdef __NR_epoll_ctl
268 137def5f 2021-07-02 op SC_ALLOW(epoll_ctl),
270 137def5f 2021-07-02 op #ifdef __NR_epoll_pwait
271 137def5f 2021-07-02 op SC_ALLOW(epoll_pwait),
273 137def5f 2021-07-02 op #ifdef __NR_epoll_wait
274 137def5f 2021-07-02 op SC_ALLOW(epoll_wait),
276 137def5f 2021-07-02 op #ifdef __NR_exit
277 137def5f 2021-07-02 op SC_ALLOW(exit),
279 137def5f 2021-07-02 op #ifdef __NR_exit_group
280 137def5f 2021-07-02 op SC_ALLOW(exit_group),
282 137def5f 2021-07-02 op #ifdef __NR_fcntl
283 137def5f 2021-07-02 op SC_ALLOW(fcntl),
285 137def5f 2021-07-02 op #ifdef __NR_fcntl64
286 137def5f 2021-07-02 op SC_ALLOW(fcntl64),
288 137def5f 2021-07-02 op #ifdef __NR_fstat
289 137def5f 2021-07-02 op SC_ALLOW(fstat),
291 21f7d246 2021-07-23 op #ifdef __NR_fstat64
292 21f7d246 2021-07-23 op SC_ALLOW(fstat64),
294 94c5f99a 2022-02-13 op #ifdef __NR_fstatat64
295 94c5f99a 2022-02-13 op SC_ALLOW(fstatat64),
297 137def5f 2021-07-02 op #ifdef __NR_getdents64
298 137def5f 2021-07-02 op SC_ALLOW(getdents64),
300 137def5f 2021-07-02 op #ifdef __NR_getpid
301 137def5f 2021-07-02 op SC_ALLOW(getpid),
303 137def5f 2021-07-02 op #ifdef __NR_getrandom
304 137def5f 2021-07-02 op SC_ALLOW(getrandom),
306 137def5f 2021-07-02 op #ifdef __NR_gettimeofday
307 137def5f 2021-07-02 op SC_ALLOW(gettimeofday),
309 137def5f 2021-07-02 op #ifdef __NR_ioctl
310 6f27d259 2021-09-26 op /* allow ioctl on fd 1, glibc doing stuff? */
311 4842c72d 2021-10-18 op SC_ALLOW_ARG(__NR_ioctl, 0, 1),
312 6f27d259 2021-09-26 op /* allow FIONREAD needed by libevent */
313 6f27d259 2021-09-26 op SC_ALLOW_ARG(__NR_ioctl, 1, FIONREAD),
315 94c5f99a 2022-02-13 op #ifdef __NR__llseek
316 94c5f99a 2022-02-13 op SC_ALLOW(_llseek),
318 137def5f 2021-07-02 op #ifdef __NR_lseek
319 137def5f 2021-07-02 op SC_ALLOW(lseek),
321 137def5f 2021-07-02 op #ifdef __NR_madvise
322 137def5f 2021-07-02 op SC_ALLOW(madvise),
324 137def5f 2021-07-02 op #ifdef __NR_mmap
325 137def5f 2021-07-02 op SC_ALLOW(mmap),
327 137def5f 2021-07-02 op #ifdef __NR_mmap2
328 137def5f 2021-07-02 op SC_ALLOW(mmap2),
330 137def5f 2021-07-02 op #ifdef __NR_munmap
331 137def5f 2021-07-02 op SC_ALLOW(munmap),
333 137def5f 2021-07-02 op #ifdef __NR_newfstatat
334 137def5f 2021-07-02 op SC_ALLOW(newfstatat),
336 137def5f 2021-07-02 op #ifdef __NR_oldfstat
337 137def5f 2021-07-02 op SC_ALLOW(oldfstat),
339 137def5f 2021-07-02 op #ifdef __NR_openat
340 4f0e893c 2022-02-13 op SC_ALLOW_ARG(__NR_openat, 3, O_RDONLY),
342 137def5f 2021-07-02 op #ifdef __NR_prlimit64
343 137def5f 2021-07-02 op SC_ALLOW(prlimit64),
345 137def5f 2021-07-02 op #ifdef __NR_read
346 137def5f 2021-07-02 op SC_ALLOW(read),
348 137def5f 2021-07-02 op #ifdef __NR_recvmsg
349 137def5f 2021-07-02 op SC_ALLOW(recvmsg),
351 a8e1e8d7 2021-07-23 op #ifdef __NR_readv
352 a8e1e8d7 2021-07-23 op SC_ALLOW(readv),
354 137def5f 2021-07-02 op #ifdef __NR_rt_sigaction
355 137def5f 2021-07-02 op SC_ALLOW(rt_sigaction),
357 137def5f 2021-07-02 op #ifdef __NR_rt_sigreturn
358 137def5f 2021-07-02 op SC_ALLOW(rt_sigreturn),
360 137def5f 2021-07-02 op #ifdef __NR_sendmsg
361 137def5f 2021-07-02 op SC_ALLOW(sendmsg),
363 94c5f99a 2022-02-13 op #ifdef __NR_sigreturn
364 94c5f99a 2022-02-13 op SC_ALLOW(sigreturn),
366 137def5f 2021-07-02 op #ifdef __NR_statx
367 137def5f 2021-07-02 op SC_ALLOW(statx),
369 63bf54b6 2021-12-11 vdrummer #ifdef __NR_ugetrlimit
370 63bf54b6 2021-12-11 vdrummer SC_ALLOW(ugetrlimit),
372 137def5f 2021-07-02 op #ifdef __NR_write
373 137def5f 2021-07-02 op SC_ALLOW(write),
375 137def5f 2021-07-02 op #ifdef __NR_writev
376 137def5f 2021-07-02 op SC_ALLOW(writev),
379 4aa1dd55 2021-07-03 op /* disallow everything else */
380 137def5f 2021-07-02 op BPF_STMT(BPF_RET | BPF_K, SC_FAIL),
383 71b7eb2f 2021-01-17 op #ifdef SC_DEBUG
385 71b7eb2f 2021-01-17 op #include <signal.h>
386 71b7eb2f 2021-01-17 op #include <unistd.h>
389 71b7eb2f 2021-01-17 op sandbox_seccomp_violation(int signum, siginfo_t *info, void *ctx)
391 71b7eb2f 2021-01-17 op fprintf(stderr, "%s: unexpected system call (arch:0x%x,syscall:%d @ %p)\n",
392 71b7eb2f 2021-01-17 op __func__, info->si_arch, info->si_syscall, info->si_call_addr);
397 71b7eb2f 2021-01-17 op sandbox_seccomp_catch_sigsys(void)
399 71b7eb2f 2021-01-17 op struct sigaction act;
400 71b7eb2f 2021-01-17 op sigset_t mask;
402 71b7eb2f 2021-01-17 op memset(&act, 0, sizeof(act));
403 71b7eb2f 2021-01-17 op sigemptyset(&mask);
404 71b7eb2f 2021-01-17 op sigaddset(&mask, SIGSYS);
406 71b7eb2f 2021-01-17 op act.sa_sigaction = &sandbox_seccomp_violation;
407 71b7eb2f 2021-01-17 op act.sa_flags = SA_SIGINFO;
408 8e56d6ad 2021-02-11 op if (sigaction(SIGSYS, &act, NULL) == -1)
409 8e56d6ad 2021-02-11 op fatal("%s: sigaction(SIGSYS): %s",
410 71b7eb2f 2021-01-17 op __func__, strerror(errno));
412 8e56d6ad 2021-02-11 op if (sigprocmask(SIG_UNBLOCK, &mask, NULL) == -1)
413 8e56d6ad 2021-02-11 op fatal("%s: sigprocmask(SIGSYS): %s\n",
414 71b7eb2f 2021-01-17 op __func__, strerror(errno));
416 71b7eb2f 2021-01-17 op #endif /* SC_DEBUG */
418 3499ce5a 2021-09-19 op #if HAVE_LANDLOCK
419 0ea22af2 2021-09-19 op static inline int
420 cb28978f 2021-09-25 op open_landlock(void)
424 e5d82d94 2022-03-19 op const struct landlock_ruleset_attr attr = {
425 98c6f8de 2022-02-10 op .handled_access_fs = LANDLOCK_ACCESS_FS_EXECUTE |
426 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_READ_FILE |
427 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_READ_DIR |
428 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_WRITE_FILE |
429 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_REMOVE_DIR |
430 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_REMOVE_FILE |
431 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_CHAR |
432 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_DIR |
433 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_REG |
434 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_SOCK |
435 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_FIFO |
436 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_BLOCK |
437 98c6f8de 2022-02-10 op LANDLOCK_ACCESS_FS_MAKE_SYM,
440 cb28978f 2021-09-25 op fd = landlock_create_ruleset(&attr, sizeof(attr), 0);
441 0ea22af2 2021-09-19 op if (fd == -1) {
442 0ea22af2 2021-09-19 op switch (errno) {
444 0ea22af2 2021-09-19 op fatal("%s: failed to create ruleset. "
445 0ea22af2 2021-09-19 op "Landlock doesn't seem to be supported by the "
446 0ea22af2 2021-09-19 op "current kernel.", __func__);
447 0ea22af2 2021-09-19 op case EOPNOTSUPP:
448 0ea22af2 2021-09-19 op log_warn(NULL, "%s: failed to create ruleset. "
449 0ea22af2 2021-09-19 op "Landlock seems to be currently disabled; "
450 0ea22af2 2021-09-19 op "continuing without it.", __func__);
453 0ea22af2 2021-09-19 op fatal("%s: failed to create ruleset: %s",
454 0ea22af2 2021-09-19 op __func__, strerror(errno));
462 cb28978f 2021-09-25 op landlock_unveil_path(int landlock_fd, const char *path, int perms)
464 cb28978f 2021-09-25 op struct landlock_path_beneath_attr pb;
465 cb28978f 2021-09-25 op int err, saved_errno;
467 cb28978f 2021-09-25 op pb.allowed_access = perms;
469 cb28978f 2021-09-25 op if ((pb.parent_fd = open(path, O_PATH)) == -1)
472 cb28978f 2021-09-25 op err = landlock_add_rule(landlock_fd, LANDLOCK_RULE_PATH_BENEATH,
474 cb28978f 2021-09-25 op saved_errno = errno;
475 cb28978f 2021-09-25 op close(pb.parent_fd);
476 cb28978f 2021-09-25 op errno = saved_errno;
477 cb28978f 2021-09-25 op return err ? -1 : 0;
481 cb28978f 2021-09-25 op landlock_apply(int fd)
483 cb28978f 2021-09-25 op int r, saved_errno;
485 cb28978f 2021-09-25 op if (fd == -1)
488 cb28978f 2021-09-25 op r = landlock_restrict_self(fd, 0);
489 cb28978f 2021-09-25 op saved_errno = errno;
491 cb28978f 2021-09-25 op errno = saved_errno;
492 cb28978f 2021-09-25 op return r ? -1 : 0;
496 3499ce5a 2021-09-19 op server_landlock(void)
498 cb28978f 2021-09-25 op int fd, perms;
499 3499ce5a 2021-09-19 op struct vhost *h;
500 3499ce5a 2021-09-19 op struct location *l;
503 3499ce5a 2021-09-19 op * These are all the actions allowed for the root directories
504 cb28978f 2021-09-25 op * of the vhosts.
506 cb28978f 2021-09-25 op perms = LANDLOCK_ACCESS_FS_READ_FILE | LANDLOCK_ACCESS_FS_READ_DIR;
508 cb28978f 2021-09-25 op if ((fd = open_landlock()) == -1)
511 3499ce5a 2021-09-19 op TAILQ_FOREACH(h, &hosts, vhosts) {
512 3499ce5a 2021-09-19 op TAILQ_FOREACH(l, &h->locations, locations) {
513 3499ce5a 2021-09-19 op if (l->dir == NULL)
516 cb28978f 2021-09-25 op if (landlock_unveil_path(fd, l->dir, perms) == -1)
517 cb28978f 2021-09-25 op fatal("%s: landlock_unveil_path(%s): %s",
518 3499ce5a 2021-09-19 op __func__, l->dir, strerror(errno));
522 cb28978f 2021-09-25 op return landlock_apply(fd);
526 b0be0653 2021-09-19 op logger_landlock(void)
530 cb28978f 2021-09-25 op if ((fd = open_landlock()) == -1)
533 cb28978f 2021-09-25 op /* no rules. the logger doesn't need fs access at all. */
535 cb28978f 2021-09-25 op return landlock_apply(fd);
540 62e001b0 2021-03-20 op sandbox_server_process(void)
542 e5d82d94 2022-03-19 op const struct sock_fprog prog = {
543 71b7eb2f 2021-01-17 op .len = (unsigned short) (sizeof(filter) / sizeof(filter[0])),
544 71b7eb2f 2021-01-17 op .filter = filter,
547 71b7eb2f 2021-01-17 op #ifdef SC_DEBUG
548 71b7eb2f 2021-01-17 op sandbox_seccomp_catch_sigsys();
551 8e56d6ad 2021-02-11 op if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == -1)
552 8e56d6ad 2021-02-11 op fatal("%s: prctl(PR_SET_NO_NEW_PRIVS): %s",
553 71b7eb2f 2021-01-17 op __func__, strerror(errno));
555 3499ce5a 2021-09-19 op #if HAVE_LANDLOCK
556 cb28978f 2021-09-25 op if (server_landlock() == -1)
557 cb28978f 2021-09-25 op fatal("%s: server_landlock: %s",
558 cb28978f 2021-09-25 op __func__, strerror(errno));
561 8e56d6ad 2021-02-11 op if (prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog) == -1)
562 8e56d6ad 2021-02-11 op fatal("%s: prctl(PR_SET_SECCOMP): %s\n",
563 71b7eb2f 2021-01-17 op __func__, strerror(errno));
567 62e001b0 2021-03-20 op sandbox_logger_process(void)
570 b0be0653 2021-09-19 op * Here we could use a seccomp filter to allow only recvfd,
571 b0be0653 2021-09-19 op * write/writev and memory allocations, but syslog is a beast
572 b0be0653 2021-09-19 op * and I don't know what syscalls it could end up doing.
573 b0be0653 2021-09-19 op * Landlock is a simpler beast, use it to disallow any file
574 b0be0653 2021-09-19 op * sytsem access.
577 f7ee7990 2021-10-02 op if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == -1)
578 f7ee7990 2021-10-02 op fatal("%s: prctl(PR_SET_NO_NEW_PRIVS): %s",
579 f7ee7990 2021-10-02 op __func__, strerror(errno));
581 b0be0653 2021-09-19 op #if HAVE_LANDLOCK
582 cb28978f 2021-09-25 op if (logger_landlock() == -1)
583 cb28978f 2021-09-25 op fatal("%s: logger_landlock: %s",
584 b0be0653 2021-09-19 op __func__, strerror(errno));
590 dafb57b8 2021-01-15 op #elif defined(__OpenBSD__)
592 dafb57b8 2021-01-15 op #include <unistd.h>
595 62e001b0 2021-03-20 op sandbox_server_process(void)
597 fdea6aa0 2021-04-30 op struct vhost *h;
598 fdea6aa0 2021-04-30 op struct location *l;
600 b8e64ccd 2021-03-31 op TAILQ_FOREACH(h, &hosts, vhosts) {
601 fdea6aa0 2021-04-30 op TAILQ_FOREACH(l, &h->locations, locations) {
602 fdea6aa0 2021-04-30 op if (l->dir == NULL)
605 fdea6aa0 2021-04-30 op if (unveil(l->dir, "r") == -1)
606 fdea6aa0 2021-04-30 op fatal("unveil %s for domain %s",
612 d29a2ee2 2022-09-06 op if (pledge("stdio recvfd rpath inet dns", NULL) == -1)
613 8e56d6ad 2021-02-11 op fatal("pledge");
617 62e001b0 2021-03-20 op sandbox_logger_process(void)
619 e952c505 2021-06-15 op if (pledge("stdio recvfd", NULL) == -1)
620 62e001b0 2021-03-20 op err(1, "pledge");
625 62e001b0 2021-03-20 op #warning "No sandbox method known for this OS"
628 62e001b0 2021-03-20 op sandbox_server_process(void)
634 62e001b0 2021-03-20 op sandbox_logger_process(void)