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-rw-r--r--kernel/auditsc.c231
1 files changed, 169 insertions, 62 deletions
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index e75f84e1a1a0..46b45abceb9a 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -39,6 +39,9 @@
#include <linux/audit.h>
#include <linux/personality.h>
#include <linux/time.h>
+#include <linux/kthread.h>
+#include <linux/netlink.h>
+#include <linux/compiler.h>
#include <asm/unistd.h>
/* 0 = no checking
@@ -95,6 +98,7 @@ struct audit_names {
uid_t uid;
gid_t gid;
dev_t rdev;
+ unsigned flags;
};
struct audit_aux_data {
@@ -167,9 +171,16 @@ struct audit_context {
/* There are three lists of rules -- one to search at task creation
* time, one to search at syscall entry time, and another to search at
* syscall exit time. */
-static LIST_HEAD(audit_tsklist);
-static LIST_HEAD(audit_entlist);
-static LIST_HEAD(audit_extlist);
+static struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
+ LIST_HEAD_INIT(audit_filter_list[0]),
+ LIST_HEAD_INIT(audit_filter_list[1]),
+ LIST_HEAD_INIT(audit_filter_list[2]),
+ LIST_HEAD_INIT(audit_filter_list[3]),
+ LIST_HEAD_INIT(audit_filter_list[4]),
+#if AUDIT_NR_FILTERS != 5
+#error Fix audit_filter_list initialiser
+#endif
+};
struct audit_entry {
struct list_head list;
@@ -210,16 +221,15 @@ static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b)
/* Note that audit_add_rule and audit_del_rule are called via
* audit_receive() in audit.c, and are protected by
* audit_netlink_sem. */
-static inline int audit_add_rule(struct audit_entry *entry,
- struct list_head *list)
+static inline void audit_add_rule(struct audit_entry *entry,
+ struct list_head *list)
{
- if (entry->rule.flags & AUDIT_PREPEND) {
- entry->rule.flags &= ~AUDIT_PREPEND;
+ if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
+ entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
list_add_rcu(&entry->list, list);
} else {
list_add_tail_rcu(&entry->list, list);
}
- return 0;
}
static void audit_free_rule(struct rcu_head *head)
@@ -245,7 +255,7 @@ static inline int audit_del_rule(struct audit_rule *rule,
return 0;
}
}
- return -EFAULT; /* No matching rule */
+ return -ENOENT; /* No matching rule */
}
/* Copy rule from user-space to kernel-space. Called during
@@ -260,6 +270,8 @@ static int audit_copy_rule(struct audit_rule *d, struct audit_rule *s)
return -1;
if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS)
return -1;
+ if ((s->flags & ~AUDIT_FILTER_PREPEND) >= AUDIT_NR_FILTERS)
+ return -1;
d->flags = s->flags;
d->action = s->action;
@@ -272,27 +284,60 @@ static int audit_copy_rule(struct audit_rule *d, struct audit_rule *s)
return 0;
}
+static int audit_list_rules(void *_dest)
+{
+ int pid, seq;
+ int *dest = _dest;
+ struct audit_entry *entry;
+ int i;
+
+ pid = dest[0];
+ seq = dest[1];
+ kfree(dest);
+
+ down(&audit_netlink_sem);
+
+ /* The *_rcu iterators not needed here because we are
+ always called with audit_netlink_sem held. */
+ for (i=0; i<AUDIT_NR_FILTERS; i++) {
+ list_for_each_entry(entry, &audit_filter_list[i], list)
+ audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
+ &entry->rule, sizeof(entry->rule));
+ }
+ audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
+
+ up(&audit_netlink_sem);
+ return 0;
+}
+
int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
uid_t loginuid)
{
- u32 flags;
struct audit_entry *entry;
+ struct task_struct *tsk;
+ int *dest;
int err = 0;
+ unsigned listnr;
switch (type) {
case AUDIT_LIST:
- /* The *_rcu iterators not needed here because we are
- always called with audit_netlink_sem held. */
- list_for_each_entry(entry, &audit_tsklist, list)
- audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
- &entry->rule, sizeof(entry->rule));
- list_for_each_entry(entry, &audit_entlist, list)
- audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
- &entry->rule, sizeof(entry->rule));
- list_for_each_entry(entry, &audit_extlist, list)
- audit_send_reply(pid, seq, AUDIT_LIST, 0, 1,
- &entry->rule, sizeof(entry->rule));
- audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
+ /* We can't just spew out the rules here because we might fill
+ * the available socket buffer space and deadlock waiting for
+ * auditctl to read from it... which isn't ever going to
+ * happen if we're actually running in the context of auditctl
+ * trying to _send_ the stuff */
+
+ dest = kmalloc(2 * sizeof(int), GFP_KERNEL);
+ if (!dest)
+ return -ENOMEM;
+ dest[0] = pid;
+ dest[1] = seq;
+
+ tsk = kthread_run(audit_list_rules, dest, "audit_list_rules");
+ if (IS_ERR(tsk)) {
+ kfree(dest);
+ err = PTR_ERR(tsk);
+ }
break;
case AUDIT_ADD:
if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL)))
@@ -301,26 +346,20 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
kfree(entry);
return -EINVAL;
}
- flags = entry->rule.flags;
- if (!err && (flags & AUDIT_PER_TASK))
- err = audit_add_rule(entry, &audit_tsklist);
- if (!err && (flags & AUDIT_AT_ENTRY))
- err = audit_add_rule(entry, &audit_entlist);
- if (!err && (flags & AUDIT_AT_EXIT))
- err = audit_add_rule(entry, &audit_extlist);
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
+ listnr = entry->rule.flags & ~AUDIT_FILTER_PREPEND;
+ audit_add_rule(entry, &audit_filter_list[listnr]);
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
"auid=%u added an audit rule\n", loginuid);
break;
case AUDIT_DEL:
- flags =((struct audit_rule *)data)->flags;
- if (!err && (flags & AUDIT_PER_TASK))
- err = audit_del_rule(data, &audit_tsklist);
- if (!err && (flags & AUDIT_AT_ENTRY))
- err = audit_del_rule(data, &audit_entlist);
- if (!err && (flags & AUDIT_AT_EXIT))
- err = audit_del_rule(data, &audit_extlist);
- audit_log(NULL, AUDIT_CONFIG_CHANGE,
- "auid=%u removed an audit rule\n", loginuid);
+ listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND;
+ if (listnr >= AUDIT_NR_FILTERS)
+ return -EINVAL;
+
+ err = audit_del_rule(data, &audit_filter_list[listnr]);
+ if (!err)
+ audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+ "auid=%u removed an audit rule\n", loginuid);
break;
default:
return -EINVAL;
@@ -454,7 +493,7 @@ static enum audit_state audit_filter_task(struct task_struct *tsk)
enum audit_state state;
rcu_read_lock();
- list_for_each_entry_rcu(e, &audit_tsklist, list) {
+ list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) {
if (audit_filter_rules(tsk, &e->rule, NULL, &state)) {
rcu_read_unlock();
return state;
@@ -478,6 +517,9 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
int word = AUDIT_WORD(ctx->major);
int bit = AUDIT_BIT(ctx->major);
+ if (audit_pid && tsk->tgid == audit_pid)
+ return AUDIT_DISABLED;
+
rcu_read_lock();
list_for_each_entry_rcu(e, list, list) {
if ((e->rule.mask[word] & bit) == bit
@@ -490,6 +532,64 @@ static enum audit_state audit_filter_syscall(struct task_struct *tsk,
return AUDIT_BUILD_CONTEXT;
}
+static int audit_filter_user_rules(struct netlink_skb_parms *cb,
+ struct audit_rule *rule,
+ enum audit_state *state)
+{
+ int i;
+
+ for (i = 0; i < rule->field_count; i++) {
+ u32 field = rule->fields[i] & ~AUDIT_NEGATE;
+ u32 value = rule->values[i];
+ int result = 0;
+
+ switch (field) {
+ case AUDIT_PID:
+ result = (cb->creds.pid == value);
+ break;
+ case AUDIT_UID:
+ result = (cb->creds.uid == value);
+ break;
+ case AUDIT_GID:
+ result = (cb->creds.gid == value);
+ break;
+ case AUDIT_LOGINUID:
+ result = (cb->loginuid == value);
+ break;
+ }
+
+ if (rule->fields[i] & AUDIT_NEGATE)
+ result = !result;
+ if (!result)
+ return 0;
+ }
+ switch (rule->action) {
+ case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
+ case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break;
+ case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break;
+ }
+ return 1;
+}
+
+int audit_filter_user(struct netlink_skb_parms *cb, int type)
+{
+ struct audit_entry *e;
+ enum audit_state state;
+ int ret = 1;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
+ if (audit_filter_user_rules(cb, &e->rule, &state)) {
+ if (state == AUDIT_DISABLED)
+ ret = 0;
+ break;
+ }
+ }
+ rcu_read_unlock();
+
+ return ret; /* Audit by default */
+}
+
/* This should be called with task_lock() held. */
static inline struct audit_context *audit_get_context(struct task_struct *tsk,
int return_valid,
@@ -504,7 +604,7 @@ static inline struct audit_context *audit_get_context(struct task_struct *tsk,
if (context->in_syscall && !context->auditable) {
enum audit_state state;
- state = audit_filter_syscall(tsk, context, &audit_extlist);
+ state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);
if (state == AUDIT_RECORD_CONTEXT)
context->auditable = 1;
}
@@ -679,13 +779,13 @@ static void audit_log_task_info(struct audit_buffer *ab)
up_read(&mm->mmap_sem);
}
-static void audit_log_exit(struct audit_context *context)
+static void audit_log_exit(struct audit_context *context, unsigned int gfp_mask)
{
int i;
struct audit_buffer *ab;
struct audit_aux_data *aux;
- ab = audit_log_start(context, AUDIT_SYSCALL);
+ ab = audit_log_start(context, gfp_mask, AUDIT_SYSCALL);
if (!ab)
return; /* audit_panic has been called */
audit_log_format(ab, "arch=%x syscall=%d",
@@ -717,7 +817,7 @@ static void audit_log_exit(struct audit_context *context)
for (aux = context->aux; aux; aux = aux->next) {
- ab = audit_log_start(context, aux->type);
+ ab = audit_log_start(context, GFP_KERNEL, aux->type);
if (!ab)
continue; /* audit_panic has been called */
@@ -754,14 +854,14 @@ static void audit_log_exit(struct audit_context *context)
}
if (context->pwd && context->pwdmnt) {
- ab = audit_log_start(context, AUDIT_CWD);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
if (ab) {
audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt);
audit_log_end(ab);
}
}
for (i = 0; i < context->name_count; i++) {
- ab = audit_log_start(context, AUDIT_PATH);
+ ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
if (!ab)
continue; /* audit_panic has been called */
@@ -770,6 +870,8 @@ static void audit_log_exit(struct audit_context *context)
audit_log_format(ab, " name=");
audit_log_untrustedstring(ab, context->names[i].name);
}
+ audit_log_format(ab, " flags=%x\n", context->names[i].flags);
+
if (context->names[i].ino != (unsigned long)-1)
audit_log_format(ab, " inode=%lu dev=%02x:%02x mode=%#o"
" ouid=%u ogid=%u rdev=%02x:%02x",
@@ -799,9 +901,11 @@ void audit_free(struct task_struct *tsk)
return;
/* Check for system calls that do not go through the exit
- * function (e.g., exit_group), then free context block. */
- if (context->in_syscall && context->auditable && context->pid != audit_pid)
- audit_log_exit(context);
+ * function (e.g., exit_group), then free context block.
+ * We use GFP_ATOMIC here because we might be doing this
+ * in the context of the idle thread */
+ if (context->in_syscall && context->auditable)
+ audit_log_exit(context, GFP_ATOMIC);
audit_free_context(context);
}
@@ -876,11 +980,11 @@ void audit_syscall_entry(struct task_struct *tsk, int arch, int major,
state = context->state;
if (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT)
- state = audit_filter_syscall(tsk, context, &audit_entlist);
+ state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]);
if (likely(state == AUDIT_DISABLED))
return;
- context->serial = audit_serial();
+ context->serial = 0;
context->ctime = CURRENT_TIME;
context->in_syscall = 1;
context->auditable = !!(state == AUDIT_RECORD_CONTEXT);
@@ -905,8 +1009,8 @@ void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code)
if (likely(!context))
return;
- if (context->in_syscall && context->auditable && context->pid != audit_pid)
- audit_log_exit(context);
+ if (context->in_syscall && context->auditable)
+ audit_log_exit(context, GFP_KERNEL);
context->in_syscall = 0;
context->auditable = 0;
@@ -996,7 +1100,7 @@ void audit_putname(const char *name)
/* Store the inode and device from a lookup. Called from
* fs/namei.c:path_lookup(). */
-void audit_inode(const char *name, const struct inode *inode)
+void audit_inode(const char *name, const struct inode *inode, unsigned flags)
{
int idx;
struct audit_context *context = current->audit_context;
@@ -1022,17 +1126,20 @@ void audit_inode(const char *name, const struct inode *inode)
++context->ino_count;
#endif
}
- context->names[idx].ino = inode->i_ino;
- context->names[idx].dev = inode->i_sb->s_dev;
- context->names[idx].mode = inode->i_mode;
- context->names[idx].uid = inode->i_uid;
- context->names[idx].gid = inode->i_gid;
- context->names[idx].rdev = inode->i_rdev;
+ context->names[idx].flags = flags;
+ context->names[idx].ino = inode->i_ino;
+ context->names[idx].dev = inode->i_sb->s_dev;
+ context->names[idx].mode = inode->i_mode;
+ context->names[idx].uid = inode->i_uid;
+ context->names[idx].gid = inode->i_gid;
+ context->names[idx].rdev = inode->i_rdev;
}
void auditsc_get_stamp(struct audit_context *ctx,
struct timespec *t, unsigned int *serial)
{
+ if (!ctx->serial)
+ ctx->serial = audit_serial();
t->tv_sec = ctx->ctime.tv_sec;
t->tv_nsec = ctx->ctime.tv_nsec;
*serial = ctx->serial;
@@ -1044,7 +1151,7 @@ int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
if (task->audit_context) {
struct audit_buffer *ab;
- ab = audit_log_start(NULL, AUDIT_LOGIN);
+ ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
if (ab) {
audit_log_format(ab, "login pid=%d uid=%u "
"old auid=%u new auid=%u",
@@ -1153,7 +1260,7 @@ void audit_signal_info(int sig, struct task_struct *t)
extern pid_t audit_sig_pid;
extern uid_t audit_sig_uid;
- if (unlikely(audit_pid && t->pid == audit_pid)) {
+ if (unlikely(audit_pid && t->tgid == audit_pid)) {
if (sig == SIGTERM || sig == SIGHUP) {
struct audit_context *ctx = current->audit_context;
audit_sig_pid = current->pid;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-16 03:47:18 +0000