[PATCH 08/12] audit: anchor all pid references in the initial pid namespace

From: Richard Guy Briggs
Date: Tue Aug 20 2013 - 17:33:48 EST

Store and log all PIDs with reference to the initial PID namespace and
deprecate the use of the error-prone duplicity of task->pid and task->tgid.

Still only permit the audit logging daemon and control to operate from the
initial PID namespace, but allow processes to log from another PID namespace.

Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
(informed by ebiederman's c776b5d2)

Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
---
drivers/tty/tty_audit.c | 3 ++-
kernel/audit.c | 15 ++++++++++-----
kernel/auditfilter.c | 17 ++++++++++++++++-
kernel/auditsc.c | 16 +++++++++-------
security/apparmor/audit.c | 2 +-
security/integrity/integrity_audit.c | 2 +-
security/lsm_audit.c | 11 +++++++----
security/tomoyo/audit.c | 2 +-
8 files changed, 47 insertions(+), 21 deletions(-)

diff --git a/drivers/tty/tty_audit.c b/drivers/tty/tty_audit.c
index a4fdce7..a0ae01f 100644
--- a/drivers/tty/tty_audit.c
+++ b/drivers/tty/tty_audit.c
@@ -65,6 +65,7 @@ static void tty_audit_log(const char *description, int major, int minor,
{
struct audit_buffer *ab;
struct task_struct *tsk = current;
+ pid_t pid = task_pid_nr_init_ns(tsk);
uid_t uid = from_kuid(&init_user_ns, task_uid(tsk));
uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(tsk));
u32 sessionid = audit_get_sessionid(tsk);
@@ -74,7 +75,7 @@ static void tty_audit_log(const char *description, int major, int minor,
char name[sizeof(tsk->comm)];

audit_log_format(ab, "%s pid=%u uid=%u auid=%u ses=%u major=%d"
- " minor=%d comm=", description, tsk->pid, uid,
+ " minor=%d comm=", description, pid, uid,
loginuid, sessionid, major, minor);
get_task_comm(name, tsk);
audit_log_untrustedstring(ab, name);
diff --git a/kernel/audit.c b/kernel/audit.c
index fa1d5f5..8e4958b 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -574,9 +574,8 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
{
int err = 0;

- /* Only support the initial namespaces for now. */
- if ((current_user_ns() != &init_user_ns) ||
- (task_active_pid_ns(current) != &init_pid_ns))
+ /* Only support initial user namespace for now. */
+ if ((current_user_ns() != &init_user_ns))
return -EPERM;

switch (msg_type) {
@@ -594,6 +593,11 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
case AUDIT_TTY_SET:
case AUDIT_TRIM:
case AUDIT_MAKE_EQUIV:
+ /* Only support auditd and auditctl in initial pid namespace
+ * for now. */
+ if ((task_active_pid_ns(current) != &init_pid_ns))
+ return -EPERM;
+
if (!capable(CAP_AUDIT_CONTROL))
err = -EPERM;
break;
@@ -614,6 +618,7 @@ static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
{
int rc = 0;
uid_t uid = from_kuid(&init_user_ns, current_uid());
+ pid_t pid = task_tgid_nr_init_ns(current);

if (!audit_enabled) {
*ab = NULL;
@@ -623,7 +628,7 @@ static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
*ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
if (unlikely(!*ab))
return rc;
- audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid);
+ audit_log_format(*ab, "pid=%d uid=%u", pid, uid);
audit_log_session_info(*ab);
audit_log_task_context(*ab);

@@ -1605,7 +1610,7 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
" euid=%u suid=%u fsuid=%u"
" egid=%u sgid=%u fsgid=%u ses=%u tty=%s",
task_ppid_nr_init_ns(tsk),
- tsk->pid,
+ task_pid_nr_init_ns(tsk),
from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
from_kuid(&init_user_ns, cred->uid),
from_kgid(&init_user_ns, cred->gid),
diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
index 381d3de..2a60455 100644
--- a/kernel/auditfilter.c
+++ b/kernel/auditfilter.c
@@ -428,6 +428,19 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
f->val = 0;
}

+ if ((f->type == AUDIT_PID) || (f->type == AUDIT_PPID)) {
+ struct pid *pid;
+ rcu_read_lock();
+ pid = find_vpid(f->val);
+ if (!pid) {
+ rcu_read_unlock();
+ err = -ESRCH;
+ goto exit_free;
+ }
+ f->val = pid_nr_init_ns(pid);
+ rcu_read_unlock();
+ }
+
err = audit_field_valid(entry, f);
if (err)
goto exit_free;
@@ -1223,12 +1236,14 @@ static int audit_filter_user_rules(struct audit_krule *rule, int type,

for (i = 0; i < rule->field_count; i++) {
struct audit_field *f = &rule->fields[i];
+ pid_t pid;
int result = 0;
u32 sid;

switch (f->type) {
case AUDIT_PID:
- result = audit_comparator(task_pid_vnr(current), f->op, f->val);
+ pid = task_pid_nr_init_ns(current);
+ result = audit_comparator(pid, f->op, f->val);
break;
case AUDIT_UID:
result = audit_uid_comparator(current_uid(), f->op, f->uid);
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 2dcf67d..5cde81c 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -458,10 +458,12 @@ static int audit_filter_rules(struct task_struct *tsk,
struct audit_field *f = &rule->fields[i];
struct audit_names *n;
int result = 0;
+ pid_t pid;

switch (f->type) {
case AUDIT_PID:
- result = audit_comparator(tsk->pid, f->op, f->val);
+ pid = task_pid_nr_init_ns(tsk);
+ result = audit_comparator(pid, f->op, f->val);
break;
case AUDIT_PPID:
if (ctx) {
@@ -1989,7 +1991,7 @@ int audit_set_loginuid(kuid_t loginuid)
audit_log_format(ab, "login pid=%d uid=%u "
"old auid=%u new auid=%u"
" old ses=%u new ses=%u",
- task->pid,
+ task_pid_nr_init_ns(task),
from_kuid(&init_user_ns, task_uid(task)),
from_kuid(&init_user_ns, task->loginuid),
from_kuid(&init_user_ns, loginuid),
@@ -2197,7 +2199,7 @@ void __audit_ptrace(struct task_struct *t)
{
struct audit_context *context = current->audit_context;

- context->target_pid = t->pid;
+ context->target_pid = task_pid_nr_init_ns(t);
context->target_auid = audit_get_loginuid(t);
context->target_uid = task_uid(t);
context->target_sessionid = audit_get_sessionid(t);
@@ -2222,7 +2224,7 @@ int __audit_signal_info(int sig, struct task_struct *t)

if (audit_pid && task_tgid(t) == audit_pid) {
if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) {
- audit_sig_pid = tsk->pid;
+ audit_sig_pid = task_pid_nr_init_ns(tsk);
if (uid_valid(tsk->loginuid))
audit_sig_uid = tsk->loginuid;
else
@@ -2236,7 +2238,7 @@ int __audit_signal_info(int sig, struct task_struct *t)
/* optimize the common case by putting first signal recipient directly
* in audit_context */
if (!ctx->target_pid) {
- ctx->target_pid = t->tgid;
+ ctx->target_pid = task_tgid_nr_init_ns(t);
ctx->target_auid = audit_get_loginuid(t);
ctx->target_uid = t_uid;
ctx->target_sessionid = audit_get_sessionid(t);
@@ -2257,7 +2259,7 @@ int __audit_signal_info(int sig, struct task_struct *t)
}
BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS);

- axp->target_pid[axp->pid_count] = t->tgid;
+ axp->target_pid[axp->pid_count] = task_tgid_nr_init_ns(t);
axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
axp->target_uid[axp->pid_count] = t_uid;
axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
@@ -2356,7 +2358,7 @@ static void audit_log_task(struct audit_buffer *ab)
from_kgid(&init_user_ns, gid),
sessionid);
audit_log_task_context(ab);
- audit_log_format(ab, " pid=%d comm=", current->pid);
+ audit_log_format(ab, " pid=%d comm=", task_pid_nr_init_ns(current));
audit_log_untrustedstring(ab, current->comm);
}

diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c
index 497b306..afe71f5 100644
--- a/security/apparmor/audit.c
+++ b/security/apparmor/audit.c
@@ -148,7 +148,7 @@ static void audit_pre(struct audit_buffer *ab, void *ca)
}

if (sa->aad->tsk) {
- audit_log_format(ab, " pid=%d comm=", tsk->pid);
+ audit_log_format(ab, " pid=%d comm=", task_pid_nr_init_ns(tsk));
audit_log_untrustedstring(ab, tsk->comm);
}

diff --git a/security/integrity/integrity_audit.c b/security/integrity/integrity_audit.c
index d7efb30..1e7291a 100644
--- a/security/integrity/integrity_audit.c
+++ b/security/integrity/integrity_audit.c
@@ -39,7 +39,7 @@ void integrity_audit_msg(int audit_msgno, struct inode *inode,

ab = audit_log_start(current->audit_context, GFP_KERNEL, audit_msgno);
audit_log_format(ab, "pid=%d uid=%u auid=%u ses=%u",
- current->pid,
+ task_pid_nr_init_ns(current),
from_kuid(&init_user_ns, current_cred()->uid),
from_kuid(&init_user_ns, audit_get_loginuid(current)),
audit_get_sessionid(current));
diff --git a/security/lsm_audit.c b/security/lsm_audit.c
index 8d8d97d..4f43488 100644
--- a/security/lsm_audit.c
+++ b/security/lsm_audit.c
@@ -220,7 +220,7 @@ static void dump_common_audit_data(struct audit_buffer *ab,
*/
BUILD_BUG_ON(sizeof(a->u) > sizeof(void *)*2);

- audit_log_format(ab, " pid=%d comm=", tsk->pid);
+ audit_log_format(ab, " pid=%d comm=", task_pid_nr_init_ns(tsk));
audit_log_untrustedstring(ab, tsk->comm);

switch (a->type) {
@@ -278,9 +278,12 @@ static void dump_common_audit_data(struct audit_buffer *ab,
}
case LSM_AUDIT_DATA_TASK:
tsk = a->u.tsk;
- if (tsk && tsk->pid) {
- audit_log_format(ab, " pid=%d comm=", tsk->pid);
- audit_log_untrustedstring(ab, tsk->comm);
+ if (tsk) {
+ pid_t pid = task_pid_nr_init_ns(tsk);
+ if (pid) {
+ audit_log_format(ab, " pid=%d comm=", pid);
+ audit_log_untrustedstring(ab, tsk->comm);
+ }
}
break;
case LSM_AUDIT_DATA_NET:
diff --git a/security/tomoyo/audit.c b/security/tomoyo/audit.c
index c1b0037..6657607 100644
--- a/security/tomoyo/audit.c
+++ b/security/tomoyo/audit.c
@@ -147,7 +147,7 @@ static inline const char *tomoyo_filetype(const umode_t mode)
static char *tomoyo_print_header(struct tomoyo_request_info *r)
{
struct tomoyo_time stamp;
- const pid_t gpid = task_pid_nr(current);
+ const pid_t gpid = task_pid_nr_init_ns(current);
struct tomoyo_obj_info *obj = r->obj;
static const int tomoyo_buffer_len = 4096;
char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
--
1.7.1

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