Blackbird™ Linux sources for OpenPOWER https://git.raptorcs.com/git/blackbird-op-linux/atom?h=master 2020-01-18T14:19:18+00:00 2020-01-18T14:19:18+00:00 Aleksa Sarai cyphar@cyphar.com 2020-01-18T12:08:00+00:00 urn:sha1:b28a10aedcd4d175470171a32f4f20b0a60a612b Test all of the various openat2(2) flags. A small stress-test of a symlink-rename attack is included to show that the protections against ".."-based attacks are sufficient. The main things these self-tests are enforcing are: * The struct+usize ABI for openat2(2) and copy_struct_from_user() to ensure that upgrades will be handled gracefully (in addition, ensuring that misaligned structures are also handled correctly). * The -EINVAL checks for openat2(2) are all correctly handled to avoid userspace passing unknown or conflicting flag sets (most importantly, ensuring that invalid flag combinations are checked). * All of the RESOLVE_* semantics (including errno values) are correctly handled with various combinations of paths and flags. * RESOLVE_IN_ROOT correctly protects against the symlink rename(2) attack that has been responsible for several CVEs (and likely will be responsible for several more). Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>