X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Faudit.c;h=b782b046543ddc9ad04541085717ed0881a3051f;hb=c92a7a54d6579c9c01374092e7b61a6161f2ef70;hp=801c946dd24b639520e6037b63dd96860c2e60d9;hpb=406a1d868001423c85a3165288e566e65f424fe6;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/audit.c b/kernel/audit.c index 801c946..b782b04 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -66,10 +66,11 @@ * (Initialization happens after skb_init is called.) */ static int audit_initialized; -/* 0 - no auditing - * 1 - auditing enabled - * 2 - auditing enabled and configuration is locked/unchangeable. */ +#define AUDIT_OFF 0 +#define AUDIT_ON 1 +#define AUDIT_LOCKED 2 int audit_enabled; +int audit_ever_enabled; /* Default state when kernel boots without any parameters. */ static int audit_default; @@ -77,9 +78,13 @@ static int audit_default; /* If auditing cannot proceed, audit_failure selects what happens. */ static int audit_failure = AUDIT_FAIL_PRINTK; -/* If audit records are to be written to the netlink socket, audit_pid - * contains the (non-zero) pid. */ +/* + * If audit records are to be written to the netlink socket, audit_pid + * contains the pid of the auditd process and audit_nlk_pid contains + * the pid to use to send netlink messages to that process. + */ int audit_pid; +static int audit_nlk_pid; /* If audit_rate_limit is non-zero, limit the rate of sending audit records * to that number per second. This prevents DoS attacks, but results in @@ -152,8 +157,10 @@ struct audit_buffer { static void audit_set_pid(struct audit_buffer *ab, pid_t pid) { - struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); - nlh->nlmsg_pid = pid; + if (ab) { + struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); + nlh->nlmsg_pid = pid; + } } void audit_panic(const char *message) @@ -163,10 +170,13 @@ void audit_panic(const char *message) case AUDIT_FAIL_SILENT: break; case AUDIT_FAIL_PRINTK: - printk(KERN_ERR "audit: %s\n", message); + if (printk_ratelimit()) + printk(KERN_ERR "audit: %s\n", message); break; case AUDIT_FAIL_PANIC: - panic("audit: %s\n", message); + /* test audit_pid since printk is always losey, why bother? */ + if (audit_pid) + panic("audit: %s\n", message); break; } } @@ -231,161 +241,107 @@ void audit_log_lost(const char *message) } if (print) { - printk(KERN_WARNING - "audit: audit_lost=%d audit_rate_limit=%d audit_backlog_limit=%d\n", - atomic_read(&audit_lost), - audit_rate_limit, - audit_backlog_limit); + if (printk_ratelimit()) + printk(KERN_WARNING + "audit: audit_lost=%d audit_rate_limit=%d " + "audit_backlog_limit=%d\n", + atomic_read(&audit_lost), + audit_rate_limit, + audit_backlog_limit); audit_panic(message); } } -static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid) +static int audit_log_config_change(char *function_name, int new, int old, + uid_t loginuid, u32 sid, int allow_changes) { - int res, rc = 0, old = audit_rate_limit; - - /* check if we are locked */ - if (audit_enabled == 2) - res = 0; - else - res = 1; + struct audit_buffer *ab; + int rc = 0; + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); + audit_log_format(ab, "%s=%d old=%d by auid=%u", function_name, new, + old, loginuid); if (sid) { char *ctx = NULL; u32 len; - 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 res=%d", - limit, old, loginuid, ctx, res); + + rc = selinux_sid_to_string(sid, &ctx, &len); + if (rc) { + audit_log_format(ab, " sid=%u", sid); + allow_changes = 0; /* Something weird, deny request */ + } else { + audit_log_format(ab, " subj=%s", ctx); 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; + audit_log_format(ab, " res=%d", allow_changes); + audit_log_end(ab); return rc; } -static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid) +static int audit_do_config_change(char *function_name, int *to_change, + int new, uid_t loginuid, u32 sid) { - int res, rc = 0, old = audit_backlog_limit; + int allow_changes, rc = 0, old = *to_change; /* check if we are locked */ - if (audit_enabled == 2) - res = 0; + if (audit_enabled == AUDIT_LOCKED) + allow_changes = 0; else - res = 1; + allow_changes = 1; - if (sid) { - char *ctx = NULL; - u32 len; - 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 res=%d", - limit, old, loginuid, ctx, res); - kfree(ctx); - } else - res = 0; /* Something weird, deny request */ + if (audit_enabled != AUDIT_OFF) { + rc = audit_log_config_change(function_name, new, old, + loginuid, sid, allow_changes); + if (rc) + allow_changes = 0; } - 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; + if (allow_changes == 1) + *to_change = new; /* Not allowed, update reason */ else if (rc == 0) rc = -EPERM; return rc; } -static int audit_set_enabled(int state, uid_t loginuid, u32 sid) +static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid) +{ + return audit_do_config_change("audit_rate_limit", &audit_rate_limit, + limit, loginuid, sid); +} + +static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid) { - int res, rc = 0, old = audit_enabled; + return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, + limit, loginuid, sid); +} - if (state < 0 || state > 2) +static int audit_set_enabled(int state, uid_t loginuid, u32 sid) +{ + int rc; + if (state < AUDIT_OFF || state > AUDIT_LOCKED) return -EINVAL; - /* check if we are locked */ - if (audit_enabled == 2) - res = 0; - else - res = 1; + rc = audit_do_config_change("audit_enabled", &audit_enabled, state, + loginuid, sid); - if (sid) { - char *ctx = NULL; - u32 len; - 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 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 (!rc) + audit_ever_enabled |= !!state; - /* 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 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; - 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 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; + return audit_do_config_change("audit_failure", &audit_failure, state, + loginuid, sid); } static int kauditd_thread(void *dummy) @@ -398,14 +354,19 @@ static int kauditd_thread(void *dummy) wake_up(&audit_backlog_wait); if (skb) { if (audit_pid) { - int err = netlink_unicast(audit_sock, skb, audit_pid, 0); + int err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0); if (err < 0) { BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */ printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); + audit_log_lost("auditd dissapeared\n"); audit_pid = 0; } } else { - printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0)); + if (printk_ratelimit()) + printk(KERN_NOTICE "%s\n", skb->data + + NLMSG_SPACE(0)); + else + audit_log_lost("printk limit exceeded\n"); kfree_skb(skb); } } else { @@ -573,6 +534,33 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) return err; } +static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type, + u32 pid, u32 uid, uid_t auid, u32 sid) +{ + int rc = 0; + char *ctx = NULL; + u32 len; + + if (!audit_enabled) { + *ab = NULL; + return rc; + } + + *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); + audit_log_format(*ab, "user pid=%d uid=%u auid=%u", + pid, uid, auid); + if (sid) { + rc = selinux_sid_to_string(sid, &ctx, &len); + if (rc) + audit_log_format(*ab, " ssid=%u", sid); + else + audit_log_format(*ab, " subj=%s", ctx); + kfree(ctx); + } + + return rc; +} + static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) { u32 uid, pid, seq, sid; @@ -583,7 +571,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) u16 msg_type = nlh->nlmsg_type; uid_t loginuid; /* loginuid of sender */ struct audit_sig_info *sig_data; - char *ctx; + char *ctx = NULL; u32 len; err = audit_netlink_ok(skb, msg_type); @@ -634,23 +622,15 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err < 0) return err; } if (status_get->mask & AUDIT_STATUS_PID) { - int old = audit_pid; - if (sid) { - if ((err = selinux_sid_to_string( - sid, &ctx, &len))) - return err; - else - audit_log(NULL, GFP_KERNEL, - AUDIT_CONFIG_CHANGE, - "audit_pid=%d old=%d by auid=%u subj=%s", - status_get->pid, old, - loginuid, ctx); - kfree(ctx); - } else - audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, - "audit_pid=%d old=%d by auid=%u", - status_get->pid, old, loginuid); - audit_pid = status_get->pid; + int new_pid = status_get->pid; + + if (audit_enabled != AUDIT_OFF) + audit_log_config_change("audit_pid", new_pid, + audit_pid, loginuid, + sid, 1); + + audit_pid = new_pid; + audit_nlk_pid = NETLINK_CB(skb).pid; } if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) err = audit_set_rate_limit(status_get->rate_limit, @@ -673,64 +653,35 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err) break; } - ab = audit_log_start(NULL, GFP_KERNEL, msg_type); - if (ab) { - audit_log_format(ab, - "user 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); - } - 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); + audit_log_common_recv_msg(&ab, msg_type, pid, uid, + loginuid, sid); + + 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); } break; case AUDIT_ADD: 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); - } + if (audit_enabled == AUDIT_LOCKED) { + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, + uid, loginuid, sid); + + audit_log_format(ab, " audit_enabled=%d res=0", + audit_enabled); + audit_log_end(ab); return -EPERM; } /* fallthrough */ @@ -743,28 +694,13 @@ 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); - } + if (audit_enabled == AUDIT_LOCKED) { + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, + uid, loginuid, sid); + + audit_log_format(ab, " audit_enabled=%d res=0", + audit_enabled); + audit_log_end(ab); return -EPERM; } /* fallthrough */ @@ -775,19 +711,10 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) break; case AUDIT_TRIM: audit_trim_trees(); - ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); - if (!ab) - break; - audit_log_format(ab, "auid=%u", loginuid); - if (sid) { - u32 len; - ctx = NULL; - if (selinux_sid_to_string(sid, &ctx, &len)) - audit_log_format(ab, " ssid=%u", sid); - else - audit_log_format(ab, " subj=%s", ctx); - kfree(ctx); - } + + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, + uid, loginuid, sid); + audit_log_format(ab, " op=trim res=1"); audit_log_end(ab); break; @@ -817,22 +744,9 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) /* OK, here comes... */ err = audit_tag_tree(old, new); - ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); - if (!ab) { - kfree(old); - kfree(new); - break; - } - audit_log_format(ab, "auid=%u", loginuid); - if (sid) { - u32 len; - ctx = NULL; - if (selinux_sid_to_string(sid, &ctx, &len)) - audit_log_format(ab, " ssid=%u", sid); - else - audit_log_format(ab, " subj=%s", ctx); - kfree(ctx); - } + audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, + uid, loginuid, sid); + audit_log_format(ab, " op=make_equiv old="); audit_log_untrustedstring(ab, old); audit_log_format(ab, " new="); @@ -965,6 +879,7 @@ static int __init audit_init(void) skb_queue_head_init(&audit_skb_queue); audit_initialized = 1; audit_enabled = audit_default; + audit_ever_enabled |= !!audit_default; /* Register the callback with selinux. This callback will be invoked * when a new policy is loaded. */ @@ -992,8 +907,10 @@ static int __init audit_enable(char *str) printk(KERN_INFO "audit: %s%s\n", audit_default ? "enabled" : "disabled", audit_initialized ? "" : " (after initialization)"); - if (audit_initialized) + if (audit_initialized) { audit_enabled = audit_default; + audit_ever_enabled |= !!audit_default; + } return 1; } @@ -1130,7 +1047,7 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, { struct audit_buffer *ab = NULL; struct timespec t; - unsigned int serial; + unsigned int uninitialized_var(serial); int reserve; unsigned long timeout_start = jiffies; @@ -1164,7 +1081,7 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, remove_wait_queue(&audit_backlog_wait, &wait); continue; } - if (audit_rate_check()) + if (audit_rate_check() && printk_ratelimit()) printk(KERN_WARNING "audit: audit_backlog=%d > " "audit_backlog_limit=%d\n", @@ -1249,6 +1166,7 @@ static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, goto out; len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); } + va_end(args2); if (len > 0) skb_put(skb, len); out: @@ -1350,9 +1268,24 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen, } /** + * audit_string_contains_control - does a string need to be logged in hex + * @string: string to be checked + * @len: max length of the string to check + */ +int audit_string_contains_control(const char *string, size_t len) +{ + const unsigned char *p; + for (p = string; p < (const unsigned char *)string + len && *p; p++) { + if (*p == '"' || *p < 0x21 || *p > 0x7f) + return 1; + } + return 0; +} + +/** * audit_log_n_untrustedstring - log a string that may contain random characters * @ab: audit_buffer - * @len: lenth of string (not including trailing null) + * @len: length 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 @@ -1363,19 +1296,13 @@ static void audit_log_n_string(struct audit_buffer *ab, size_t slen, * The caller specifies the number of characters in the string to log, which may * or may not be the entire string. */ -const char *audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, - const char *string) +void audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, + const char *string) { - const unsigned char *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; - } - } - audit_log_n_string(ab, len, string); - return p + 1; + if (audit_string_contains_control(string, len)) + audit_log_hex(ab, string, len); + else + audit_log_n_string(ab, len, string); } /** @@ -1386,33 +1313,33 @@ const char *audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, * 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) +void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) { - return audit_log_n_untrustedstring(ab, strlen(string), string); + audit_log_n_untrustedstring(ab, strlen(string), string); } /* This is a helper-function to print the escaped d_path */ void audit_log_d_path(struct audit_buffer *ab, const char *prefix, - struct dentry *dentry, struct vfsmount *vfsmnt) + struct path *path) { - char *p, *path; + char *p, *pathname; if (prefix) audit_log_format(ab, " %s", prefix); /* We will allow 11 spaces for ' (deleted)' to be appended */ - path = kmalloc(PATH_MAX+11, ab->gfp_mask); - if (!path) { + pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); + if (!pathname) { audit_log_format(ab, ""); return; } - p = d_path(dentry, vfsmnt, path, PATH_MAX+11); + p = d_path(path, pathname, PATH_MAX+11); if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ /* FIXME: can we save some information here? */ audit_log_format(ab, ""); } else audit_log_untrustedstring(ab, p); - kfree(path); + kfree(pathname); } /** @@ -1431,14 +1358,19 @@ void audit_log_end(struct audit_buffer *ab) if (!audit_rate_check()) { audit_log_lost("rate limit exceeded"); } else { + struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); if (audit_pid) { - 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; wake_up_interruptible(&kauditd_wait); - } else { - printk(KERN_NOTICE "%s\n", ab->skb->data + NLMSG_SPACE(0)); + } else if (nlh->nlmsg_type != AUDIT_EOE) { + if (printk_ratelimit()) { + printk(KERN_NOTICE "type=%d %s\n", + nlh->nlmsg_type, + ab->skb->data + NLMSG_SPACE(0)); + } else + audit_log_lost("printk limit exceeded\n"); } } audit_buffer_free(ab);