New wrappers:
- `AllowEpollWait` (`epoll_wait`, `epoll_pwait`, `epoll_pwait2`)
- `AllowInotifyInit` (`inotify_init`, `inotify_init1`)
- `AllowSelect` (`select`, `pselect6`)
- `AllowDup` (`dup`, `dup2`, `dup3`)
- `AllowPipe` (`pipe`, `pipe2`)
- `AllowChmod` (`chmod`, `fchmod`, `fchmodat`)
- `AllowChown` (`chown`, `lchown`, `fchown`, `fchownat`)
- `AllowReadlink` (`readlink`, `readlinkat`)
- `AllowLink` (`link`, `linkat`)
- `AllowSymlink` (`symlink`, `symlinkat`)
- `AllowMkdir` (`mkdir`, `mkdirat`)
- `AllowUtime` (`utime`, `utimes`, `futimens`, `utimensat`)
- `AllowAlarm` (`alarm`, `setitimer`)
- `AllowGetPGIDs` (`getpgid`, `getpgrp`)
- `AllowPoll` (`poll`, `ppoll`)
Updated wrappers:
- `AllowOpen` now includes `creat`. `openat` already grants the ability to create files, and is the designated replacement for `creat` on newer platforms.
- `AllowStat` now includes `fstatfs` and `fstatfs64`. The comment already claimed that these syscalls were included; I believe they were omitted by accident.
- `AllowUnlink` now includes `rmdir`. `unlinkat` already grants the ability to remove empty directories, and is the designated replacement for `rmdir` on newer platforms.
PiperOrigin-RevId: 495045432
Change-Id: I41eccb74fda250b27586b6b7fe4c480332e48846
On successful completion, `unw_step()` returns a positive value
if the updated cursor refers to a valid stack frame,
or `0` if the previous stack frame was the last frame in the
chain. On error, the negative value of one of the error-codes
below is returned.
PiperOrigin-RevId: 491588164
Change-Id: Ie361023ef69eed6c895856832a8208f2791f644d
Follow-up changes might be required to fully fix up the contrib sandboxes.
PiperOrigin-RevId: 482475998
Change-Id: Iff631eb838a024b2f047a1be61bb27e35a8ff2f4
This change allows Sandbox2 to change how the default FD for comms is chosen.
PiperOrigin-RevId: 479526309
Change-Id: I69add85a244bc0385eaa164ab0ea3b036503c6d3
This is to abstract the FD number away, so that we can change the way the FD number is chosen/communicated.
PiperOrigin-RevId: 479282707
Change-Id: Ic6726bcd0a17e97bde60804476ecbca2ffbf6525
We have removed an internal-only sandbox mechanism that has been deprecated
for years. Some formatting/include changes may leak into the OSS version.
PiperOrigin-RevId: 475230500
Change-Id: Ib4efdf3282529ea50e8302e5ef7acfdd7d4c68e5
If it isn't, assume that the process has exited and the event msg contains an exit code.
PiperOrigin-RevId: 471258449
Change-Id: I44408c30fe7fb39e20b55cea871f3efb68fcde67
Instead of doing waitpid() and processing one thread at a time, gather all waiting threads and then process them.
This avoids starving older threads when newer threads raise a lot of events.
PiperOrigin-RevId: 466366533
Change-Id: I81a878f038feac86407a8e961ecba181004f0f8a
E.g. a failed `KillSandboxee` for a timeout would already set the exit status code while there could be an external kill pending at the same time which would try to `KillSandboxee` again and thus set exit status code again.
PiperOrigin-RevId: 448464765
Change-Id: Ic5744a576c4255504bfb1d5c4f33253b5bb32b6f
This should make multithreaded sandboxees that exec (or send `SIGKILL`) behave more reliably.
PiperOrigin-RevId: 447458426
Change-Id: Ifdace340462199dc24c8cdf25d589ef6b24991e1
Instead of calling `google::InitGoogleLogging()` directly, introduce an
indirection via a new utility library. After this change, Sandboxed API
should consistently use `sapi::InitLogging()` everywhere.
For now, `sapi::InitLogging()` simply calls its glog equivalent. However,
this enables us to migrate away from the gflags dependency and use Abseil
flags. Once a follow-up change lands, `sapi::InitLogging()` will instead
initialize the google logging library with flags defined from Aseil.
Later still, once Abseil releases logging, we can then drop the glog
dependency entirely.
PiperOrigin-RevId: 445363592
Change-Id: Ia23a7dc88b8ffe65a422ea4d5233bba7bdd1303a
Internally, we rely on clang-tidy to warn about using deprecated declarations.
And for using deprecated declarations within SAPI itself, we should not warn.
Drive-by:
- Fix warning in `mounts_test.cc`
PiperOrigin-RevId: 443634512
Change-Id: I7ef66f0ba77201026490baab07766510c1c55c6a
`BUILD_TESTING` is a CMake provided option and we should use similar naming,
just like how Abseil does it.
- `SAPI_ENABLE_TESTS` -> `SAPI_BUILD_TESTING`
- `SAPI_ENABLE_CONTRIB_TESTS` -> `SAPI_CONTRIB_BUILD_TESTING`
- `SAPI_ENABLE_EXAMPLES` -> `SAPI_BUILD_EXAMPLES`
Drive-by:
- Fix option name in GitHub action
PiperOrigin-RevId: 443305932
Change-Id: Ice2b42be1229a0f9ae7c2ceda9ce87187baf22c4
Including the `CTest` modules ensures that the `BUILD_TESTING` option is
defined and automatically calls `enable_testing()` if needed. It does not
change the default or introduce any dependencies on its own.
This follows what Abseil already does in their top-level `CMakeLists.txt`.
PiperOrigin-RevId: 443305646
Change-Id: If067c17470f497437c7748aab4aab5227c26e84f
This fixes the main issue (#118) with stack traces on Fedora, which uses a
`/lib64` and `/usr/lib64`.
PiperOrigin-RevId: 437717858
Change-Id: I6986aa84c2be57ae1d9f8d0cb9b508768d27f1c1
The feature is pure optimization, but it requires
additional syscalls.
PiperOrigin-RevId: 432954277
Change-Id: I1f345f8a26c86e09611fd575cb6ee080f24cc717
munmap is widely used by sanitizer, but it
probably works for Asan/Msan because it's enabled
by unrelated Allow* call.
Move mprotect to shared part as well. It will be
needed for compress_stack_depot.
PiperOrigin-RevId: 431989551
Change-Id: I7695a2de81d8d0b2112d3308778b2e9a9c7cb596
Linking glibc in fully static mode is mostly unsupported. While such binaries
can easily be produced, conflicting symbols will often make them crash at
runtime. This happens because glibc will always (try to) load some dynamically
linked libraries, even when statically linked. This includes things like the
resolver, unicode/locale handling and others.
Internally at Google, this is not a concern due to the way glibc is being built
there. But in order to make all of our tests run in the open-source version of
this code, we need to change strategy a bit.
As a rule of thumb, glibc can safely be linked statically if a program is
resonably simple and does not use any networking of locale dependent
facilities. Calling syscalls directly instead of the corresponding libc
wrappers works as well, of course.
This change adjusts linker flags and sandbox policies to be more compatible
with regular Linux distributions.
Tested:
- `ctest -R '[A-Z].*'` (all SAPI/Sandbox2 tests)
PiperOrigin-RevId: 429025901
Change-Id: I46b677d9eb61080a8fe868002a34a77de287bf2d
- Link `zipe.c` statically (safe)
- Update policy to allow any use of `stat()`
PiperOrigin-RevId: 428971638
Change-Id: Ib0f5f496ea2389582986b41a8830592e6c1d4390
This fixes a couple of tests in the open source version of the code.
Internally, since we are using a different ELF loader, the page offset
will always be zero. Hence we never notices this was broken.
PiperOrigin-RevId: 427996428
Change-Id: I44c5b5610b074cf69b9f0c5eeb051be50923e351
Note that `//sandboxed_api/sandbox2:stack_trace_test` may still fail for
unrelated reasons, as we are linking libc statically, which is brittle. A
follow-up change will fix this.
PiperOrigin-RevId: 427175045
Change-Id: Ifb5ec2ac3d60f4bcc9708f26c834c83b75e769d7
Newer versions of libunwind use `PTRACE_GETREGSET` to obtain register data.
This change should make it easier to upgrade the libunwind dependency.
PiperOrigin-RevId: 420057842
Change-Id: Ib9abbeff574e457009709715f912ba5962033c5d
- Allow to specify multiple syscalls with `BlockSyscallsWithErrno()`
- Add functions to allow `unlink()` and `rename()` in all their spellings
PiperOrigin-RevId: 414987303
Change-Id: Ic0e680b785e8e3a3498f20e6a7403737e63fe876
__sanitizer_sandbox_on_notify is not tsan specific.
It's empty for other sanitizers now, but we are going to need it soon.
PiperOrigin-RevId: 414873197
Change-Id: I251ac38e5c886980b4baa7f05306643599a25090
Move VecStringToCharPtrArr before fork, so that it cannot deadlock when other thread holds allocation lock.
PiperOrigin-RevId: 414661912
Change-Id: Ie8aa5c36693e6f86c69d67a1da51b7e7ff1ec30b
Different versions of the `elf.h` header define their own integer types. For
example, even on LP64 systems, a 64-bit ELF integer types may decay into
`unsigned long long` instead of `unsigned long`.
This change replaces the various overloads with a single function template
that is well-defined for all integral types.
PiperOrigin-RevId: 410746713
Change-Id: I4b560f7541802372f01ae3d6f4a56554e51d70c8
Generate syscall jump table without using bpf_helper.
Check that any jump in the user provided policy is within the provided policy.
PiperOrigin-RevId: 409362089
Change-Id: I31493e52cf868e4b184ff79fcb26beeb75f49773
Note: This change allows `MAP_NORESERVE` generally, not just for MSAN. This follows
what we do for `AllowTcMalloc()/AllowSystemMalloc()`
PiperOrigin-RevId: 402231980
Change-Id: Ifa1c6b9f61f636dd6db231dde3765c3b4a40911b
These were previously dependent on an internal-only testing target.
For now, this only works with Bazel, but should enable us to have better test coverage in GitHub actions.
Eventually, all of these shell-based tests should be converted to `cc_test`s.
PiperOrigin-RevId: 400713615
Change-Id: I1cabb5b72977987ef4a1803480f699b58c4d56e9
For OSS, this change should be mostly a no-op. Visible edits are due to
changed order of code and/or includes.
PiperOrigin-RevId: 394177395
Change-Id: I1d32f9fd175579e8f05c051b1307953b249d139d
This mainly a debugging facility.
It makes diagnosing problems where sandboxed process just randomly exits whereas unsandboxed one runs to completion due to differences in the setup/environment much easier.
PiperOrigin-RevId: 391005548
Change-Id: Ia19fe6632748da93c1f4291bb55e895f50a4e2b0
Otherwise starting forkserver multiple times will result in zombie processes lingering around.
PiperOrigin-RevId: 388926497
Change-Id: Ia9947cce3d9e909edd709b0d3525e1ae8b8bbc51
Also really own `exec_fd_` as previously if the executor is destructed without calling `StartSubProcess` the file descriptor would leak.
PiperOrigin-RevId: 388901766
Change-Id: I6bbb15ced37a0a832ec5a5228452a3d54ef46ee9
Calling `Terminate()` issues additional syscalls that may clobber the `errno`
value. Reordering the log statements ensures we actually log the initial error
in `read()`/`write()`.
PiperOrigin-RevId: 387576942
Change-Id: I0f9c8c6001e6dc4ca098abe02cd251029f92a737
1. In many cases, sandboxes need to allow /proc/stat and /proc/cpuinfo so that
get_nprocs(3) will work; otherwise, per-CPU logic can't determine how many CPUs
there are. Unfortunately, some of those sandboxes also disable namespaces. The
solution is to provide two functions: AllowRestartableSequencesWithProcFiles(),
which allows syscalls and files; and AllowRestartableSequences(), which allows
syscalls only. Sandboxes should usually call the former; sandboxes that disable
namespaces should instead call the latter and are responsible for allowing the
files via the deprecated Fs mechanism.
2. Make the mmap(2) policy evaluate prot AND flags, not prot OR flags.
3. Order the code and the comments identically for better readability.
PiperOrigin-RevId: 386414028
Change-Id: I016b1854ed1da9c9bcff7b351c5e0041093b8193
The existing function signature took a `unique_ptr<>` owning a vector, and
took `nullptr` to mean an empty set of capabilities. This is more naturally
modeled by taking the vector directly and `std::move`-ing it.
PiperOrigin-RevId: 384214849
Change-Id: I177f04a06803ae00429b19a1f3f12e7be04d2908
- Assign to `*mutable_XXX()` instead of looping
- Use a const ref for capabilities
PiperOrigin-RevId: 384192675
Change-Id: I4db3d0c8ce0d7f6acc9fd486a2409962516b5fe7
This bug only manifests if a lot of fds are open when global forkserver is started.
If the allocated exec_fd number was equal Comms::kSandbox2ClientCommsFD then it would be replaced by the comms fd and result in EACCESS at execveat.
PiperOrigin-RevId: 380805414
Change-Id: I31427fa929abfc60890477b55790cc14c749f7f5
Recenly, Debian based distribution kernels started activating the Tomoyo Linux
Security Module by default. Even if it is not used, this changes the behavior
of `/dev/fd` (pointing to `/proc/self/fd` by default), which Sandbox2 needs during
`execveat()`.
As a result, Sandbox2 and Sandboxed API always fail without one of the following
conditions
- `/proc` mounted within the sandboxee
- `/dev` mounted
- `/dev/fd` symlinked to `/proc/self/fd` in the sandboxee's mount namespace
Some code pointers to upstream Linux 5.12.2:
- https://elixir.bootlin.com/linux/v5.12.2/source/fs/exec.c#L1775
- https://elixir.bootlin.com/linux/v5.12.2/source/security/tomoyo/tomoyo.c#L107
- https://elixir.bootlin.com/linux/v5.12.2/source/security/tomoyo/domain.c#L729
To find out whether your system has Tomoyo enabled, use this command, similar to
what this change does in code:
```
$ cat /sys/kernel/security/lsm | grep tomoyo && echo "Tomoyo active"
capability,yama,apparmor,tomoyo
Tomoyo active
```
The config setting `CONFIG_DEFAULT_SECURITY` controls which LSMs are built into
the kernel by default.
PiperOrigin-RevId: 372919524
Change-Id: I2181819c04f15f57d96c44ea9977d0def4a1b623
