1 files changed, 165 insertions, 67 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index d9b690ac684b..4e9d20829681 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -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
@@ -65,7 +65,9 @@
  * (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 +151,7 @@ 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;
 }
 
@@ -239,102 +241,150 @@ 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)
@@ -599,6 +649,30 @@ 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 +683,30 @@ 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,
@@ -652,7 +750,7 @@ 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 +795,7 @@ 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 +1073,7 @@ 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 +1082,7 @@ 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 +1143,7 @@ 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 +1175,7 @@ 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;
@@ -1170,7 +1268,7 @@ 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;