xz: Skip Capsicum sandbox system calls when they are unsupported.

If a system has the Capsicum header files but does not actually
implement the system calls, then this would render xz unusable. Instead,
we can check if errno == ENOSYS and not issue a fatal error.
This commit is contained in:
Jia Tan 2023-03-06 21:27:53 +08:00
parent f070722b57
commit 61ee82cb12
1 changed files with 17 additions and 5 deletions

View File

@ -193,24 +193,24 @@ io_sandbox_enter(int src_fd)
cap_rights_t rights;
if (cap_enter())
goto error;
goto capsicum_error;
if (cap_rights_limit(src_fd, cap_rights_init(&rights,
CAP_EVENT, CAP_FCNTL, CAP_LOOKUP, CAP_READ, CAP_SEEK)))
goto error;
goto capsicum_error;
if (cap_rights_limit(STDOUT_FILENO, cap_rights_init(&rights,
CAP_EVENT, CAP_FCNTL, CAP_FSTAT, CAP_LOOKUP,
CAP_WRITE, CAP_SEEK)))
goto error;
goto capsicum_error;
if (cap_rights_limit(user_abort_pipe[0], cap_rights_init(&rights,
CAP_EVENT)))
goto error;
goto capsicum_error;
if (cap_rights_limit(user_abort_pipe[1], cap_rights_init(&rights,
CAP_WRITE)))
goto error;
goto capsicum_error;
#elif defined(HAVE_PLEDGE)
// pledge() was introduced in OpenBSD 5.9.
@ -231,6 +231,18 @@ io_sandbox_enter(int src_fd)
//message(V_DEBUG, _("Sandbox was successfully enabled"));
return;
#ifdef HAVE_CAPSICUM
capsicum_error:
// Even though it is undocumented, if a kernel is configured without
// capability mode support or used in an emulator that does not
// implement the capability system calls, then the capsicum system
// calls will fail and set errno to ENOSYS.
if (errno == ENOSYS) {
sandbox_allowed = false;
return;
}
#endif
error:
message_fatal(_("Failed to enable the sandbox"));
}