From 411daeaa532c47328ab901a7ba9ea5dcd876be06 Mon Sep 17 00:00:00 2001 From: Tiago Natel Date: Fri, 6 Dec 2019 16:52:50 +0000 Subject: Isolation: allowed the use of credentials with unpriv userns. The setuid/setgid syscalls requires root capabilities but if the kernel supports unprivileged user namespace then the child process has the full set of capabilities in the new namespace, then we can allow setting "user" and "group" in such cases (this is a common security use case). Tests were added to ensure user gets meaningful error messages for uid/gid mapping misconfigurations. --- src/nxt_process.c | 32 ++++++++++++++++++++++++++------ 1 file changed, 26 insertions(+), 6 deletions(-) (limited to 'src/nxt_process.c') diff --git a/src/nxt_process.c b/src/nxt_process.c index 75c6ef25..035f747f 100644 --- a/src/nxt_process.c +++ b/src/nxt_process.c @@ -23,6 +23,12 @@ nxt_pid_t nxt_pid; /* An original parent process pid. */ nxt_pid_t nxt_ppid; +/* A cached process effective uid */ +nxt_uid_t nxt_euid; + +/* A cached process effective gid */ +nxt_gid_t nxt_egid; + nxt_bool_t nxt_proc_conn_matrix[NXT_PROCESS_MAX][NXT_PROCESS_MAX] = { { 1, 1, 1, 1, 1 }, { 1, 0, 0, 0, 0 }, @@ -207,8 +213,9 @@ nxt_process_create(nxt_task_t *task, nxt_process_t *process) } #if (NXT_HAVE_CLONE && NXT_HAVE_CLONE_NEWUSER) - if ((init->isolation.clone.flags & CLONE_NEWUSER) == CLONE_NEWUSER) { - ret = nxt_clone_proc_map(task, pid, &init->isolation.clone); + if (NXT_CLONE_USER(init->isolation.clone.flags)) { + ret = nxt_clone_credential_map(task, pid, init->user_cred, + &init->isolation.clone); if (nxt_slow_path(ret != NXT_OK)) { goto fail; } @@ -257,7 +264,7 @@ cleanup: static void nxt_process_start(nxt_task_t *task, nxt_process_t *process) { - nxt_int_t ret; + nxt_int_t ret, cap_setid; nxt_port_t *port, *main_port; nxt_thread_t *thread; nxt_runtime_t *rt; @@ -276,9 +283,22 @@ nxt_process_start(nxt_task_t *task, nxt_process_t *process) nxt_random_init(&thread->random); - if (rt->capabilities.setid && init->user_cred != NULL) { - ret = nxt_credential_set(task, init->user_cred); - if (ret != NXT_OK) { + cap_setid = rt->capabilities.setid; + +#if (NXT_HAVE_CLONE_NEWUSER) + if (!cap_setid && NXT_CLONE_USER(init->isolation.clone.flags)) { + cap_setid = 1; + } +#endif + + if (cap_setid) { + ret = nxt_credential_setgids(task, init->user_cred); + if (nxt_slow_path(ret != NXT_OK)) { + goto fail; + } + + ret = nxt_credential_setuid(task, init->user_cred); + if (nxt_slow_path(ret != NXT_OK)) { goto fail; } } -- cgit