| commit | c53e37bab4e01a58400b18d2f9cb68d4a3d3575c | [log] [tgz] |
|---|---|---|
| author | Brian Ho <hob@chromium.org> | Mon Jul 26 17:58:40 2021 |
| committer | Copybara-Service <copybara-worker@google.com> | Tue Jul 27 12:07:12 2021 |
| tree | 3a02cae24ecda0d148263131936fa3ce1e540cb6 | |
| parent | 9f4aead3898887867cc770fc882377bb9d1b6558 [diff] |
Use EACCES over EPERM for broker process denied errno When dlopen is called without an absolute path, it looks in a number of search paths for the requested library (e.g. /lib64/libfoo.so, /usr/lib/libfoo.so). Often, these files don't exist and the corresponding openat syscall should return ENOENT, but because of the GPU sandbox, the syscall returns EPERM instead [1]. glibc's implementation of dlopen, however, early-exits when it sees an unexpected errno [2] and terminates without attempting the remaining search paths. Thus, even if the library *is* allowlisted in a later path, dlopen will still exit with a failure. This CL fixes this issue by changing the denied errno to EACCES for the broker process. Bug: 1233028 Change-Id: I192098eb072f2ee6fb18aa7da3d1998f8328149f Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3054490 Reviewed-by: Matthew Denton <mpdenton@chromium.org> Reviewed-by: Robert Sesek <rsesek@chromium.org> Commit-Queue: Brian Ho <hob@chromium.org> Cr-Commit-Position: refs/heads/master@{#905330} NOKEYCHECK=True GitOrigin-RevId: 0d437e022154a5a5509d1232deec787b2a0fa5ea
This directory contains platform-specific sandboxing libraries. Sandboxing is a technique that can improve the security of an application by separating untrustworthy code (or code that handles untrustworthy data) and restricting its privileges and capabilities.
Each platform relies on the operating system's process primitive to isolate code into distinct security principals, and platform-specific technologies are used to implement the privilege reduction. At a high-level:
mac/ uses the Seatbelt sandbox. See the detailed design for more.linux/ uses namespaces and Seccomp-BPF. See the detailed design for more.win/ uses a combination of restricted tokens, distinct job objects, alternate desktops, and integrity levels. See the detailed design for more.Built on top of the low-level sandboxing library is the //sandbox/policy component, which provides concrete policies and helper utilities for sandboxing specific Chromium processes and services. The core sandbox library cannot depend on the policy component.