Closed Bug 1014107 Opened 10 years ago Closed 8 years ago

open("/proc/cpuinfo") in Skia breaks seccomp

Categories

(Core :: Security: Process Sandboxing, defect)

ARM
Gonk (Firefox OS)
defect
Not set
normal

Tracking

()

RESOLVED WONTFIX

People

(Reporter: arroway, Unassigned)

References

Details

(Whiteboard: sb-)

In gfx/skia/trunk/src/core/SkUtilsArm.cpp, the function sk_cpu_arm_check_neon opens "/cpu/procinfo". It also calls android_getCpuFeatures performing the same kind of action on Android. It looks like it is yet another external library we can't modify to manually remote open calls (cf gfx/skia/README_MOZILLA).
Blocks: 930258
No longer depends on: 930258
Blocks: 1121295
No longer blocks: 930258
Move process sandboxing bugs to their new, separate component. (Sorry for the bugspam; filter on 3c21328c-8cfb-4819-9d88-f6e965067350.)
Component: Security → Security: Process Sandboxing
Whiteboard: sb-
Summary: open("/cpu/procinfo") in Skia breaks seccomp → open("/proc/cpuinfo") in Skia breaks seccomp
With recent Skia updates, we have modified Skia to use our own mozilla::supports_neon() call instead of using Skia's own checking. This theoretically should resolve this problems on Android builds. Does it look okay now?
Flags: needinfo?(stephouillon)
Julian, could you have a look? I looked quickly at the code, but I'm behind regarding the last changes in the sandbox. Please forward if you know a better person. Thx!
Flags: needinfo?(stephouillon) → needinfo?(julian.r.hector)
Sure I can take a look, but how can it violate seccomp. Unless it is the b2g emulator, all the other platforms either don't have seccomp enabled or sys_open() is whitelisted. Where did you encounter this?
Flags: needinfo?(julian.r.hector) → needinfo?(stephouillon)
This is one of the B2G “reduce filesystem whitelist” bugs — it's an issue that's not breaking things currently, but it would block removing a whitelist entry. Rewording the summaries for this kind of bug might make that clearer.
OS: Linux → Gonk (Firefox OS)
Hardware: x86_64 → ARM
Ok thanks :jld, I think this is not an issue right now, and we probably have to handle sys_open slightly different on desktop.
Flags: needinfo?(stephouillon)
B2G-specific sandboxing bugs are WONTFIX. (I'm reasonably sure these bugs don't have implications for other platforms, but comment if I missed something.)
Status: NEW → RESOLVED
Closed: 8 years ago
Resolution: --- → WONTFIX
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