diff options
Diffstat (limited to 'kernel/audit.c')
| -rw-r--r-- | kernel/audit.c | 205 |
1 files changed, 158 insertions, 47 deletions
diff --git a/kernel/audit.c b/kernel/audit.c index df57b49..7dfac70 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -56,6 +56,7 @@ #include <linux/skbuff.h> #include <linux/netlink.h> #include <linux/selinux.h> +#include <linux/inotify.h> #include "audit.h" @@ -89,6 +90,7 @@ static int audit_backlog_wait_overflow = 0; /* The identity of the user shutting down the audit system. */ uid_t audit_sig_uid = -1; pid_t audit_sig_pid = -1; +u32 audit_sig_sid = 0; /* Records can be lost in several ways: 0) [suppressed in audit_alloc] @@ -102,6 +104,12 @@ static atomic_t audit_lost = ATOMIC_INIT(0); /* The netlink socket. */ static struct sock *audit_sock; +/* Inotify handle. */ +struct inotify_handle *audit_ih; + +/* Hash for inode-based rules */ +struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; + /* The audit_freelist is a list of pre-allocated audit buffers (if more * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of * being placed on the freelist). */ @@ -114,10 +122,8 @@ static struct task_struct *kauditd_task; static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); -/* The netlink socket is only to be read by 1 CPU, which lets us assume - * that list additions and deletions never happen simultaneously in - * auditsc.c */ -DEFINE_MUTEX(audit_netlink_mutex); +/* Serialize requests from userspace. */ +static DEFINE_MUTEX(audit_cmd_mutex); /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting * audit records. Since printk uses a 1024 byte buffer, this buffer @@ -250,7 +256,7 @@ static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid) "audit_rate_limit=%d old=%d by auid=%u", limit, old, loginuid); audit_rate_limit = limit; - return old; + return 0; } static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid) @@ -273,7 +279,7 @@ static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid) "audit_backlog_limit=%d old=%d by auid=%u", limit, old, loginuid); audit_backlog_limit = limit; - return old; + return 0; } static int audit_set_enabled(int state, uid_t loginuid, u32 sid) @@ -299,7 +305,7 @@ static int audit_set_enabled(int state, uid_t loginuid, u32 sid) "audit_enabled=%d old=%d by auid=%u", state, old, loginuid); audit_enabled = state; - return old; + return 0; } static int audit_set_failure(int state, uid_t loginuid, u32 sid) @@ -327,7 +333,7 @@ static int audit_set_failure(int state, uid_t loginuid, u32 sid) "audit_failure=%d old=%d by auid=%u", state, old, loginuid); audit_failure = state; - return old; + return 0; } static int kauditd_thread(void *dummy) @@ -363,9 +369,52 @@ static int kauditd_thread(void *dummy) remove_wait_queue(&kauditd_wait, &wait); } } +} + +int audit_send_list(void *_dest) +{ + struct audit_netlink_list *dest = _dest; + int pid = dest->pid; + struct sk_buff *skb; + + /* wait for parent to finish and send an ACK */ + mutex_lock(&audit_cmd_mutex); + mutex_unlock(&audit_cmd_mutex); + + while ((skb = __skb_dequeue(&dest->q)) != NULL) + netlink_unicast(audit_sock, skb, pid, 0); + + kfree(dest); + return 0; } +struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, + int multi, void *payload, int size) +{ + struct sk_buff *skb; + struct nlmsghdr *nlh; + int len = NLMSG_SPACE(size); + void *data; + int flags = multi ? NLM_F_MULTI : 0; + int t = done ? NLMSG_DONE : type; + + skb = alloc_skb(len, GFP_KERNEL); + if (!skb) + return NULL; + + nlh = NLMSG_PUT(skb, pid, seq, t, size); + nlh->nlmsg_flags = flags; + data = NLMSG_DATA(nlh); + memcpy(data, payload, size); + return skb; + +nlmsg_failure: /* Used by NLMSG_PUT */ + if (skb) + kfree_skb(skb); + return NULL; +} + /** * audit_send_reply - send an audit reply message via netlink * @pid: process id to send reply to @@ -383,29 +432,13 @@ void audit_send_reply(int pid, int seq, int type, int done, int multi, void *payload, int size) { struct sk_buff *skb; - struct nlmsghdr *nlh; - int len = NLMSG_SPACE(size); - void *data; - int flags = multi ? NLM_F_MULTI : 0; - int t = done ? NLMSG_DONE : type; - - skb = alloc_skb(len, GFP_KERNEL); + skb = audit_make_reply(pid, seq, type, done, multi, payload, size); if (!skb) return; - - nlh = NLMSG_PUT(skb, pid, seq, t, size); - nlh->nlmsg_flags = flags; - data = NLMSG_DATA(nlh); - memcpy(data, payload, size); - /* Ignore failure. It'll only happen if the sender goes away, because our timeout is set to infinite. */ netlink_unicast(audit_sock, skb, pid, 0); return; - -nlmsg_failure: /* Used by NLMSG_PUT */ - if (skb) - kfree_skb(skb); } /* @@ -451,7 +484,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) struct audit_buffer *ab; u16 msg_type = nlh->nlmsg_type; uid_t loginuid; /* loginuid of sender */ - struct audit_sig_info sig_data; + struct audit_sig_info *sig_data; + char *ctx; + u32 len; err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type); if (err) @@ -503,12 +538,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (status_get->mask & AUDIT_STATUS_PID) { int old = audit_pid; if (sid) { - char *ctx = NULL; - u32 len; - int rc; - if ((rc = selinux_ctxid_to_string( + if ((err = selinux_ctxid_to_string( sid, &ctx, &len))) - return rc; + return err; else audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, @@ -523,10 +555,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) audit_pid = status_get->pid; } if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) - audit_set_rate_limit(status_get->rate_limit, + err = audit_set_rate_limit(status_get->rate_limit, loginuid, sid); if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) - audit_set_backlog_limit(status_get->backlog_limit, + err = audit_set_backlog_limit(status_get->backlog_limit, loginuid, sid); break; case AUDIT_USER: @@ -544,8 +576,6 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) "user pid=%d uid=%u auid=%u", pid, uid, loginuid); if (sid) { - char *ctx = NULL; - u32 len; if (selinux_ctxid_to_string( sid, &ctx, &len)) { audit_log_format(ab, @@ -584,10 +614,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) loginuid, sid); break; case AUDIT_SIGNAL_INFO: - sig_data.uid = audit_sig_uid; - sig_data.pid = audit_sig_pid; + err = selinux_ctxid_to_string(audit_sig_sid, &ctx, &len); + if (err) + return err; + sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); + if (!sig_data) { + kfree(ctx); + return -ENOMEM; + } + sig_data->uid = audit_sig_uid; + sig_data->pid = audit_sig_pid; + memcpy(sig_data->ctx, ctx, len); + kfree(ctx); audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO, - 0, 0, &sig_data, sizeof(sig_data)); + 0, 0, sig_data, sizeof(*sig_data) + len); + kfree(sig_data); break; default: err = -EINVAL; @@ -629,20 +670,30 @@ static void audit_receive(struct sock *sk, int length) struct sk_buff *skb; unsigned int qlen; - mutex_lock(&audit_netlink_mutex); + mutex_lock(&audit_cmd_mutex); for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) { skb = skb_dequeue(&sk->sk_receive_queue); audit_receive_skb(skb); kfree_skb(skb); } - mutex_unlock(&audit_netlink_mutex); + mutex_unlock(&audit_cmd_mutex); } +#ifdef CONFIG_AUDITSYSCALL +static const struct inotify_operations audit_inotify_ops = { + .handle_event = audit_handle_ievent, + .destroy_watch = audit_free_parent, +}; +#endif /* Initialize audit support at boot time. */ static int __init audit_init(void) { +#ifdef CONFIG_AUDITSYSCALL + int i; +#endif + printk(KERN_INFO "audit: initializing netlink socket (%s)\n", audit_default ? "enabled" : "disabled"); audit_sock = netlink_kernel_create(NETLINK_AUDIT, 0, audit_receive, @@ -661,6 +712,16 @@ static int __init audit_init(void) selinux_audit_set_callback(&selinux_audit_rule_update); audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); + +#ifdef CONFIG_AUDITSYSCALL + audit_ih = inotify_init(&audit_inotify_ops); + if (IS_ERR(audit_ih)) + audit_panic("cannot initialize inotify handle"); + + for (i = 0; i < AUDIT_INODE_BUCKETS; i++) + INIT_LIST_HEAD(&audit_inode_hash[i]); +#endif + return 0; } __initcall(audit_init); @@ -690,10 +751,12 @@ static void audit_buffer_free(struct audit_buffer *ab) kfree_skb(ab->skb); spin_lock_irqsave(&audit_freelist_lock, flags); - if (++audit_freelist_count > AUDIT_MAXFREE) + if (audit_freelist_count > AUDIT_MAXFREE) kfree(ab); - else + else { + audit_freelist_count++; list_add(&ab->list, &audit_freelist); + } spin_unlock_irqrestore(&audit_freelist_lock, flags); } @@ -988,28 +1051,76 @@ void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, skb_put(skb, len << 1); /* new string is twice the old string */ } +/* + * Format a string of no more than slen characters into the audit buffer, + * enclosed in quote marks. + */ +static void audit_log_n_string(struct audit_buffer *ab, size_t slen, + const char *string) +{ + int avail, new_len; + unsigned char *ptr; + struct sk_buff *skb; + + BUG_ON(!ab->skb); + skb = ab->skb; + avail = skb_tailroom(skb); + new_len = slen + 3; /* enclosing quotes + null terminator */ + if (new_len > avail) { + avail = audit_expand(ab, new_len); + if (!avail) + return; + } + ptr = skb->tail; + *ptr++ = '"'; + memcpy(ptr, string, slen); + ptr += slen; + *ptr++ = '"'; + *ptr = 0; + skb_put(skb, slen + 2); /* don't include null terminator */ +} + /** - * audit_log_unstrustedstring - log a string that may contain random characters + * audit_log_n_unstrustedstring - log a string that may contain random characters * @ab: audit_buffer + * @len: lenth of string (not including trailing null) * @string: string to be logged * * This code will escape a string that is passed to it if the string * contains a control character, unprintable character, double quote mark, * or a space. Unescaped strings will start and end with a double quote mark. * Strings that are escaped are printed in hex (2 digits per char). + * + * The caller specifies the number of characters in the string to log, which may + * or may not be the entire string. */ -void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) +const char *audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, + const char *string) { const unsigned char *p = string; while (*p) { if (*p == '"' || *p < 0x21 || *p > 0x7f) { - audit_log_hex(ab, string, strlen(string)); - return; + audit_log_hex(ab, string, len); + return string + len + 1; } p++; } - audit_log_format(ab, "\"%s\"", string); + audit_log_n_string(ab, len, string); + return p + 1; +} + +/** + * audit_log_unstrustedstring - 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 + * determine string length. + */ +const char *audit_log_untrustedstring(struct audit_buffer *ab, const char *string) +{ + return audit_log_n_untrustedstring(ab, strlen(string), string); } /* This is a helper-function to print the escaped d_path */ |