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
This is needed for some compiler versions where `absl::string_view` == `std::string_view`.
PiperOrigin-RevId: 367392064
Change-Id: Id91d23510501df4745f386475ef9049d94062e1b
This changes the workflow definition so that we always try to install
compiler toolchains that we need.
See https://github.com/actions/virtual-environments/issues/2950 for more
context.
Drive-by:
- Mini fix to enable compilation under Clang 6.0
Signed-off-by: Christian Blichmann <cblichmann@google.com>
Now unwinding will properly handle binaries inside bind-mounted directories.
Drive-by:
- Get rid of n^2 path handling
- Get rid of namespace alias
PiperOrigin-RevId: 358353666
Change-Id: Ieec7690ec6a1ae6d358de375220566b69e8cb094
Using C++17 means we can get rid of many `#ifdef`s by using `if constexpr`.
This way, we ensure that both branches compile and still retain zero runtime
overhead.
Note that open source builds of Sandboxed API do not ship with sanitizer
configurations yet. This will be added in follow-up changes.
PiperOrigin-RevId: 354932160
Change-Id: I3678dffc47ea873919f0a8c01f3a7d999fc29a5b
