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 change should make it less confusing where utility code comes from.
Having it in two places made sense when we were debating whether to publish
Sandbox2 separately, but not any longer.
Follow-up changes will move `sandbox2/util.h` and rename the remaining
`sandbox2/util` folder.
PiperOrigin-RevId: 351601640
Change-Id: I6256845261f610e590c25e2c59851cc51da2d778
The defined raw logging macros should be compatible with Abseil and
we can remove our version once Abseil releases theirs.
PiperOrigin-RevId: 347354273
Change-Id: I178a89cfd2e19bcd707a06fa9dfd7b767e2b654b
This allows us to remove some uses of macros.
Related changes:
- Make it clear that we support hosting sandboxed binaries from 64-bit
processes only. CPU architectures are x86-64 and POWER64 (little endian).
- Introduced CPU architecture macros, abstracting away compiler specifics
PiperOrigin-RevId: 330918134
Change-Id: Ife7ad5f14723eec9f68055127b0583b8aecd38dd
- Drop `delim` argument from the `GetStackTrace()` family of functions.
We only ever used plain spaces.
- Use an `std::vector<std::string>` for the symbolized stack frames and
adjust the unwind proto accordingly.
This change now prints each stack frame on its own line while skipping
duplicate ones:
```
I20200717 11:47:16.811381 3636246 monitor.cc:326] Stack trace: [
I20200717 11:47:16.811415 3636246 monitor.cc:337] map:/lib/x86_64-linux-gnu/libc-2.30.so+0xceee7(0x7fb871602ee7)
I20200717 11:47:16.811420 3636246 monitor.cc:337] Rot13File+0x130(0x55ed24615995)
I20200717 11:47:16.811424 3636246 monitor.cc:337] ffi_call_unix64+0x55(0x55ed2461f2dd)
I20200717 11:47:16.811429 3636246 monitor.cc:337] map:[stack]+0x1ec80(0x7ffee4257c80)
I20200717 11:47:16.811455 3636246 monitor.cc:339] (last frame repeated 196 times)
I20200717 11:47:16.811460 3636246 monitor.cc:347] ]
```
PiperOrigin-RevId: 322089140
Change-Id: I05b0de2f4118fed90fe920c06bbd70ea0d1119e2
Process might be killed between waitpid and PTRACE_CONT,
even though a PTRACE_EVENT_EXIT will be gererated, continuing
will fail with ESRCH in that case.
PiperOrigin-RevId: 249245726
Change-Id: Ib673529229a306d2266fa60caa3039b6bcd80a65
After all requested filesystem mounts are fully mounted under a sandboxee's virtual chroot, print a list of the outside paths and a list of the inside chroot paths that the outside paths are mapped to. This provides a valuable insight while debugging sandboxed binaries.
PiperOrigin-RevId: 247130923
Change-Id: I42b4b3db68d826587c0fe8127aabbead38bc6f20
