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Cód Saincheisteanna 21 Iarratais Tarraingthe 1 Scaoileann Gníomhaíocht

Sandbox: Remove multiple stages

Brabhsáil Foinse 
While interesitng in theory, there is nothing to be gained here,
because we don't really have user input at those early stages.

As we are also not a privileged process, those early stage
sandboxes in the end are not worth it, since they increase
complexity while there is no benefit in practise.

So, reduce those 3 stages to a single one (enable()), which we
activate after CLI server has launched.
Tá an tiomantas seo le fáil i:
Albert S.
2021-10-03 23:46:40 +02:00
tuismitheoir 257675485d
tiomantas c4072a7e95
D'athraigh 5 comhad le 30 breiseanna agus 110 scriosta
Íoslódáil an comhad paiste Íoslódáil Comhad Diff Leathnaigh gach comhaid Laghdaigh gach comhaid

82
sandbox/sandbox-linux.cpp
Féach ar an gComhad

@ -23,68 +23,6 @@
* obvious systemcalls. To whitelist, we need to analyse our
* dependencies (http library, sqlite wrapper, sqlite lib etc.) */
bool SandboxLinux::enableForInit()
{
umask(0027);
struct qssb_policy *policy = qssb_init_policy();
if(policy == NULL)
{
Logger::error() << "Failed to init sandboxing policy (init)";
return false;
}
policy->namespace_options = QSSB_UNSHARE_USER;
policy->drop_caps = 0;
qssb_append_syscall_policy(policy, QSSB_SYSCALL_DENY_KILL_PROCESS, QSSB_SYS(execveat));
qssb_append_syscall_policy(policy, QSSB_SYSCALL_DENY_KILL_PROCESS, QSSB_SYS(execve));
qssb_append_syscall_default_policy(policy, QSSB_SYSCALL_ALLOW);
int result = qssb_enable_policy(policy);
if(result != 0)
{
Logger::error() << "Failed to enable sandboxing policy (init): " << result;
qssb_free_policy(policy);
return false;
}
qssb_free_policy(policy);
return true;
}
bool SandboxLinux::enablePreWorker(std::vector<std::string> fsPaths)
{
std::sort(fsPaths.begin(), fsPaths.end(),
[](const std::string &a, const std::string &b) { return a.length() < b.length(); });
struct qssb_policy *policy = qssb_init_policy();
if(policy == NULL)
{
Logger::error() << "Failed to init sandboxing policy (pre)";
return false;
}
for(unsigned int i = 0; i < fsPaths.size(); i++)
{
qssb_append_path_policy(policy, QSSB_FS_ALLOW_READ | QSSB_FS_ALLOW_WRITE, fsPaths[i].c_str());
}
policy->namespace_options = QSSB_UNSHARE_MOUNT;
policy->drop_caps = 0;
policy->mount_path_policies_to_chroot = 1;
qssb_append_syscall_policy(policy, QSSB_SYSCALL_DENY_KILL_PROCESS, QSSB_SYS(execveat));
qssb_append_syscall_policy(policy, QSSB_SYSCALL_DENY_KILL_PROCESS, QSSB_SYS(execve));
qssb_append_syscall_default_policy(policy, QSSB_SYSCALL_ALLOW);
int result = qssb_enable_policy(policy);
if(result != 0)
{
Logger::error() << "Failed to install sandboxing policy (preworker): %i" << result;
qssb_free_policy(policy);
return false;
}
qssb_free_policy(policy);
return true;
}
bool SandboxLinux::supported()
{
std::fstream stream;
@ -102,27 +40,33 @@ bool SandboxLinux::supported()
}
return true;
}
bool SandboxLinux::enableForWorker()
bool SandboxLinux::enable(std::vector<std::string> fsPaths)
{
std::sort(fsPaths.begin(), fsPaths.end(),
[](const std::string &a, const std::string &b) { return a.length() < b.length(); });
struct qssb_policy *policy = qssb_init_policy();
if(policy == NULL)
{
Logger::error() << "Failed to init sandboxing policy (worker) ";
return false;
}
for(unsigned int i = 0; i < fsPaths.size(); i++)
{
qssb_append_path_policy(policy, QSSB_FS_ALLOW_READ | QSSB_FS_ALLOW_WRITE, fsPaths[i].c_str());
}
policy->drop_caps = 1;
policy->not_dumpable = 1;
policy->no_new_privs = 1;
policy->namespace_options = 0;
policy->mount_path_policies_to_chroot = 1;
/* TODO: as said, a whitelist approach is better. As such, this list is bound to be incomplete in the
* sense that more could be listed here and some critical ones are probably missing */
/* TODO: use qssb groups */
long blacklisted_syscalls[] = {QSSB_SYS(setuid), QSSB_SYS(connect), QSSB_SYS(chroot), QSSB_SYS(pivot_root),
QSSB_SYS(mount), QSSB_SYS(setns), QSSB_SYS(unshare), QSSB_SYS(ptrace),
QSSB_SYS(personality), QSSB_SYS(prctl)};
long blacklisted_syscalls[] = {QSSB_SYS(setuid), QSSB_SYS(connect), QSSB_SYS(chroot), QSSB_SYS(pivot_root),
QSSB_SYS(mount), QSSB_SYS(setns), QSSB_SYS(unshare), QSSB_SYS(ptrace),
QSSB_SYS(personality), QSSB_SYS(prctl), QSSB_SYS(execveat), QSSB_SYS(execve),
QSSB_SYS(fork)};
qssb_append_syscalls_policy(policy, QSSB_SYSCALL_DENY_KILL_PROCESS, blacklisted_syscalls,
sizeof(blacklisted_syscalls) / sizeof(blacklisted_syscalls[0]));
qssb_append_syscall_default_policy(policy, QSSB_SYSCALL_ALLOW);