Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[pandora-kernel.git] / kernel / audit.c
index d9b690a..eb0f916 100644 (file)
@@ -2,7 +2,7 @@
  * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
  * System-call specific features have moved to auditsc.c
  *
- * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina.
+ * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
  * All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or modify
@@ -58,6 +58,7 @@
 #include <linux/selinux.h>
 #include <linux/inotify.h>
 #include <linux/freezer.h>
+#include <linux/tty.h>
 
 #include "audit.h"
 
@@ -65,7 +66,9 @@
  * (Initialization happens after skb_init is called.) */
 static int     audit_initialized;
 
-/* No syscall auditing will take place unless audit_enabled != 0. */
+/* 0 - no auditing
+ * 1 - auditing enabled
+ * 2 - auditing enabled and configuration is locked/unchangeable. */
 int            audit_enabled;
 
 /* Default state when kernel boots without any parameters. */
@@ -149,7 +152,7 @@ struct audit_buffer {
 
 static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
 {
-       struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data;
+       struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
        nlh->nlmsg_pid = pid;
 }
 
@@ -239,108 +242,157 @@ void audit_log_lost(const char *message)
 
 static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid)
 {
-       int old = audit_rate_limit;
+       int res, rc = 0, old = audit_rate_limit;
+
+       /* check if we are locked */
+       if (audit_enabled == 2)
+               res = 0;
+       else
+               res = 1;
 
        if (sid) {
                char *ctx = NULL;
                u32 len;
-               int rc;
-               if ((rc = selinux_sid_to_string(sid, &ctx, &len)))
-                       return rc;
-               else
+               if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
                        audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
-                               "audit_rate_limit=%d old=%d by auid=%u subj=%s",
-                               limit, old, loginuid, ctx);
-               kfree(ctx);
-       } else
-               audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
-                       "audit_rate_limit=%d old=%d by auid=%u",
-                       limit, old, loginuid);
-       audit_rate_limit = limit;
-       return 0;
+                               "audit_rate_limit=%d old=%d by auid=%u"
+                               " subj=%s res=%d",
+                               limit, old, loginuid, ctx, res);
+                       kfree(ctx);
+               } else
+                       res = 0; /* Something weird, deny request */
+       }
+       audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+               "audit_rate_limit=%d old=%d by auid=%u res=%d",
+               limit, old, loginuid, res);
+
+       /* If we are allowed, make the change */
+       if (res == 1)
+               audit_rate_limit = limit;
+       /* Not allowed, update reason */
+       else if (rc == 0)
+               rc = -EPERM;
+       return rc;
 }
 
 static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid)
 {
-       int old = audit_backlog_limit;
+       int res, rc = 0, old = audit_backlog_limit;
+
+       /* check if we are locked */
+       if (audit_enabled == 2)
+               res = 0;
+       else
+               res = 1;
 
        if (sid) {
                char *ctx = NULL;
                u32 len;
-               int rc;
-               if ((rc = selinux_sid_to_string(sid, &ctx, &len)))
-                       return rc;
-               else
+               if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
                        audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
-                           "audit_backlog_limit=%d old=%d by auid=%u subj=%s",
-                               limit, old, loginuid, ctx);
-               kfree(ctx);
-       } else
-               audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
-                       "audit_backlog_limit=%d old=%d by auid=%u",
-                       limit, old, loginuid);
-       audit_backlog_limit = limit;
-       return 0;
+                               "audit_backlog_limit=%d old=%d by auid=%u"
+                               " subj=%s res=%d",
+                               limit, old, loginuid, ctx, res);
+                       kfree(ctx);
+               } else
+                       res = 0; /* Something weird, deny request */
+       }
+       audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+               "audit_backlog_limit=%d old=%d by auid=%u res=%d",
+               limit, old, loginuid, res);
+
+       /* If we are allowed, make the change */
+       if (res == 1)
+               audit_backlog_limit = limit;
+       /* Not allowed, update reason */
+       else if (rc == 0)
+               rc = -EPERM;
+       return rc;
 }
 
 static int audit_set_enabled(int state, uid_t loginuid, u32 sid)
 {
-       int old = audit_enabled;
+       int res, rc = 0, old = audit_enabled;
 
-       if (state != 0 && state != 1)
+       if (state < 0 || state > 2)
                return -EINVAL;
 
+       /* check if we are locked */
+       if (audit_enabled == 2)
+               res = 0;
+       else
+               res = 1;
+
        if (sid) {
                char *ctx = NULL;
                u32 len;
-               int rc;
-               if ((rc = selinux_sid_to_string(sid, &ctx, &len)))
-                       return rc;
-               else
+               if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
                        audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
-                               "audit_enabled=%d old=%d by auid=%u subj=%s",
-                               state, old, loginuid, ctx);
-               kfree(ctx);
-       } else
-               audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
-                       "audit_enabled=%d old=%d by auid=%u",
-                       state, old, loginuid);
-       audit_enabled = state;
-       return 0;
+                               "audit_enabled=%d old=%d by auid=%u"
+                               " subj=%s res=%d",
+                               state, old, loginuid, ctx, res);
+                       kfree(ctx);
+               } else
+                       res = 0; /* Something weird, deny request */
+       }
+       audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+               "audit_enabled=%d old=%d by auid=%u res=%d",
+               state, old, loginuid, res);
+
+       /* If we are allowed, make the change */
+       if (res == 1)
+               audit_enabled = state;
+       /* Not allowed, update reason */
+       else if (rc == 0)
+               rc = -EPERM;
+       return rc;
 }
 
 static int audit_set_failure(int state, uid_t loginuid, u32 sid)
 {
-       int old = audit_failure;
+       int res, rc = 0, old = audit_failure;
 
        if (state != AUDIT_FAIL_SILENT
            && state != AUDIT_FAIL_PRINTK
            && state != AUDIT_FAIL_PANIC)
                return -EINVAL;
 
+       /* check if we are locked */
+       if (audit_enabled == 2)
+               res = 0;
+       else
+               res = 1;
+
        if (sid) {
                char *ctx = NULL;
                u32 len;
-               int rc;
-               if ((rc = selinux_sid_to_string(sid, &ctx, &len)))
-                       return rc;
-               else
+               if ((rc = selinux_sid_to_string(sid, &ctx, &len)) == 0) {
                        audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
-                               "audit_failure=%d old=%d by auid=%u subj=%s",
-                               state, old, loginuid, ctx);
-               kfree(ctx);
-       } else
-               audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
-                       "audit_failure=%d old=%d by auid=%u",
-                       state, old, loginuid);
-       audit_failure = state;
-       return 0;
+                               "audit_failure=%d old=%d by auid=%u"
+                               " subj=%s res=%d",
+                               state, old, loginuid, ctx, res);
+                       kfree(ctx);
+               } else
+                       res = 0; /* Something weird, deny request */
+       }
+       audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE,
+               "audit_failure=%d old=%d by auid=%u res=%d",
+               state, old, loginuid, res);
+
+       /* If we are allowed, make the change */
+       if (res == 1)
+               audit_failure = state;
+       /* Not allowed, update reason */
+       else if (rc == 0)
+               rc = -EPERM;
+       return rc;
 }
 
 static int kauditd_thread(void *dummy)
 {
        struct sk_buff *skb;
 
+       set_freezable();
        while (!kthread_should_stop()) {
                skb = skb_dequeue(&audit_skb_queue);
                wake_up(&audit_backlog_wait);
@@ -373,6 +425,31 @@ static int kauditd_thread(void *dummy)
        return 0;
 }
 
+static int audit_prepare_user_tty(pid_t pid, uid_t loginuid)
+{
+       struct task_struct *tsk;
+       int err;
+
+       read_lock(&tasklist_lock);
+       tsk = find_task_by_pid(pid);
+       err = -ESRCH;
+       if (!tsk)
+               goto out;
+       err = 0;
+
+       spin_lock_irq(&tsk->sighand->siglock);
+       if (!tsk->signal->audit_tty)
+               err = -EPERM;
+       spin_unlock_irq(&tsk->sighand->siglock);
+       if (err)
+               goto out;
+
+       tty_audit_push_task(tsk, loginuid);
+out:
+       read_unlock(&tasklist_lock);
+       return err;
+}
+
 int audit_send_list(void *_dest)
 {
        struct audit_netlink_list *dest = _dest;
@@ -461,12 +538,14 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
        case AUDIT_DEL:
        case AUDIT_DEL_RULE:
        case AUDIT_SIGNAL_INFO:
+       case AUDIT_TTY_GET:
+       case AUDIT_TTY_SET:
                if (security_netlink_recv(skb, CAP_AUDIT_CONTROL))
                        err = -EPERM;
                break;
        case AUDIT_USER:
-       case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
-       case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2:
+       case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
+       case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
                if (security_netlink_recv(skb, CAP_AUDIT_WRITE))
                        err = -EPERM;
                break;
@@ -564,14 +643,19 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                                                        loginuid, sid);
                break;
        case AUDIT_USER:
-       case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG:
-       case AUDIT_FIRST_USER_MSG2...AUDIT_LAST_USER_MSG2:
+       case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
+       case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
                if (!audit_enabled && msg_type != AUDIT_USER_AVC)
                        return 0;
 
                err = audit_filter_user(&NETLINK_CB(skb), msg_type);
                if (err == 1) {
                        err = 0;
+                       if (msg_type == AUDIT_USER_TTY) {
+                               err = audit_prepare_user_tty(pid, loginuid);
+                               if (err)
+                                       break;
+                       }
                        ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
                        if (ab) {
                                audit_log_format(ab,
@@ -588,8 +672,17 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                                                        " subj=%s", ctx);
                                        kfree(ctx);
                                }
-                               audit_log_format(ab, " msg='%.1024s'",
-                                        (char *)data);
+                               if (msg_type != AUDIT_USER_TTY)
+                                       audit_log_format(ab, " msg='%.1024s'",
+                                                        (char *)data);
+                               else {
+                                       int size;
+
+                                       audit_log_format(ab, " msg=");
+                                       size = nlmsg_len(nlh);
+                                       audit_log_n_untrustedstring(ab, size,
+                                                                   data);
+                               }
                                audit_set_pid(ab, pid);
                                audit_log_end(ab);
                        }
@@ -599,6 +692,30 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        case AUDIT_DEL:
                if (nlmsg_len(nlh) < sizeof(struct audit_rule))
                        return -EINVAL;
+               if (audit_enabled == 2) {
+                       ab = audit_log_start(NULL, GFP_KERNEL,
+                                       AUDIT_CONFIG_CHANGE);
+                       if (ab) {
+                               audit_log_format(ab,
+                                                "pid=%d uid=%u auid=%u",
+                                                pid, uid, loginuid);
+                               if (sid) {
+                                       if (selinux_sid_to_string(
+                                                       sid, &ctx, &len)) {
+                                               audit_log_format(ab,
+                                                       " ssid=%u", sid);
+                                               /* Maybe call audit_panic? */
+                                       } else
+                                               audit_log_format(ab,
+                                                       " subj=%s", ctx);
+                                       kfree(ctx);
+                               }
+                               audit_log_format(ab, " audit_enabled=%d res=0",
+                                       audit_enabled);
+                               audit_log_end(ab);
+                       }
+                       return -EPERM;
+               }
                /* fallthrough */
        case AUDIT_LIST:
                err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
@@ -609,6 +726,30 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        case AUDIT_DEL_RULE:
                if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
                        return -EINVAL;
+               if (audit_enabled == 2) {
+                       ab = audit_log_start(NULL, GFP_KERNEL,
+                                       AUDIT_CONFIG_CHANGE);
+                       if (ab) {
+                               audit_log_format(ab,
+                                                "pid=%d uid=%u auid=%u",
+                                                pid, uid, loginuid);
+                               if (sid) {
+                                       if (selinux_sid_to_string(
+                                                       sid, &ctx, &len)) {
+                                               audit_log_format(ab,
+                                                       " ssid=%u", sid);
+                                               /* Maybe call audit_panic? */
+                                       } else
+                                               audit_log_format(ab,
+                                                       " subj=%s", ctx);
+                                       kfree(ctx);
+                               }
+                               audit_log_format(ab, " audit_enabled=%d res=0",
+                                       audit_enabled);
+                               audit_log_end(ab);
+                       }
+                       return -EPERM;
+               }
                /* fallthrough */
        case AUDIT_LIST_RULES:
                err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
@@ -632,6 +773,45 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                                0, 0, sig_data, sizeof(*sig_data) + len);
                kfree(sig_data);
                break;
+       case AUDIT_TTY_GET: {
+               struct audit_tty_status s;
+               struct task_struct *tsk;
+
+               read_lock(&tasklist_lock);
+               tsk = find_task_by_pid(pid);
+               if (!tsk)
+                       err = -ESRCH;
+               else {
+                       spin_lock_irq(&tsk->sighand->siglock);
+                       s.enabled = tsk->signal->audit_tty != 0;
+                       spin_unlock_irq(&tsk->sighand->siglock);
+               }
+               read_unlock(&tasklist_lock);
+               audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_TTY_GET, 0, 0,
+                                &s, sizeof(s));
+               break;
+       }
+       case AUDIT_TTY_SET: {
+               struct audit_tty_status *s;
+               struct task_struct *tsk;
+
+               if (nlh->nlmsg_len < sizeof(struct audit_tty_status))
+                       return -EINVAL;
+               s = data;
+               if (s->enabled != 0 && s->enabled != 1)
+                       return -EINVAL;
+               read_lock(&tasklist_lock);
+               tsk = find_task_by_pid(pid);
+               if (!tsk)
+                       err = -ESRCH;
+               else {
+                       spin_lock_irq(&tsk->sighand->siglock);
+                       tsk->signal->audit_tty = s->enabled != 0;
+                       spin_unlock_irq(&tsk->sighand->siglock);
+               }
+               read_unlock(&tasklist_lock);
+               break;
+       }
        default:
                err = -EINVAL;
                break;
@@ -652,7 +832,7 @@ static void audit_receive_skb(struct sk_buff *skb)
        u32             rlen;
 
        while (skb->len >= NLMSG_SPACE(0)) {
-               nlh = (struct nlmsghdr *)skb->data;
+               nlh = nlmsg_hdr(skb);
                if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
                        return;
                rlen = NLMSG_ALIGN(nlh->nlmsg_len);
@@ -697,7 +877,7 @@ static int __init audit_init(void)
        printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
               audit_default ? "enabled" : "disabled");
        audit_sock = netlink_kernel_create(NETLINK_AUDIT, 0, audit_receive,
-                                          THIS_MODULE);
+                                          NULL, THIS_MODULE);
        if (!audit_sock)
                audit_panic("cannot initialize netlink socket");
        else
@@ -975,7 +1155,7 @@ static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
                        goto out;
        }
        va_copy(args2, args);
-       len = vsnprintf(skb->tail, avail, fmt, args);
+       len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
        if (len >= avail) {
                /* The printk buffer is 1024 bytes long, so if we get
                 * here and AUDIT_BUFSIZ is at least 1024, then we can
@@ -984,7 +1164,7 @@ static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
                        max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
                if (!avail)
                        goto out;
-               len = vsnprintf(skb->tail, avail, fmt, args2);
+               len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
        }
        if (len > 0)
                skb_put(skb, len);
@@ -1045,7 +1225,7 @@ void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf,
                        return;
        }
 
-       ptr = skb->tail;
+       ptr = skb_tail_pointer(skb);
        for (i=0; i<len; i++) {
                *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */
                *ptr++ = hex[buf[i] & 0x0F];      /* Lower nibble */
@@ -1077,7 +1257,7 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen,
                if (!avail)
                        return;
        }
-       ptr = skb->tail;
+       ptr = skb_tail_pointer(skb);
        *ptr++ = '"';
        memcpy(ptr, string, slen);
        ptr += slen;
@@ -1087,7 +1267,7 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen,
 }
 
 /**
- * audit_log_n_unstrustedstring - log a string that may contain random characters
+ * audit_log_n_untrustedstring - log a string that may contain random characters
  * @ab: audit_buffer
  * @len: lenth of string (not including trailing null)
  * @string: string to be logged
@@ -1103,25 +1283,24 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen,
 const char *audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len,
                                        const char *string)
 {
-       const unsigned char *p = string;
+       const unsigned char *p;
 
-       while (*p) {
+       for (p = string; p < (const unsigned char *)string + len && *p; p++) {
                if (*p == '"' || *p < 0x21 || *p > 0x7f) {
                        audit_log_hex(ab, string, len);
                        return string + len + 1;
                }
-               p++;
        }
        audit_log_n_string(ab, len, string);
        return p + 1;
 }
 
 /**
- * audit_log_unstrustedstring - log a string that may contain random characters
+ * audit_log_untrustedstring - log a string that may contain random characters
  * @ab: audit_buffer
  * @string: string to be logged
  *
- * Same as audit_log_n_unstrustedstring(), except that strlen is used to
+ * Same as audit_log_n_untrustedstring(), except that strlen is used to
  * determine string length.
  */
 const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
@@ -1170,7 +1349,7 @@ void audit_log_end(struct audit_buffer *ab)
                audit_log_lost("rate limit exceeded");
        } else {
                if (audit_pid) {
-                       struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data;
+                       struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
                        nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0);
                        skb_queue_tail(&audit_skb_queue, ab->skb);
                        ab->skb = NULL;