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author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 18:41:22 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-29 18:41:22 (GMT) |
commit | 9781db7b345b5dfe93787aaaf310c861db7c1ede (patch) | |
tree | d9796e29fd914ca04835636be95bbd5082a034fd /kernel/audit.c | |
parent | 97094dcf5cefc8ccfdf93839f54dac2c4d316165 (diff) | |
parent | 8b67dca9420474623709e00d72a066068a502b20 (diff) | |
download | linux-fsl-qoriq-9781db7b345b5dfe93787aaaf310c861db7c1ede.tar.xz |
Merge branch 'audit.b50' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current
* 'audit.b50' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
[PATCH] new predicate - AUDIT_FILETYPE
[patch 2/2] Use find_task_by_vpid in audit code
[patch 1/2] audit: let userspace fully control TTY input auditing
[PATCH 2/2] audit: fix sparse shadowed variable warnings
[PATCH 1/2] audit: move extern declarations to audit.h
Audit: MAINTAINERS update
Audit: increase the maximum length of the key field
Audit: standardize string audit interfaces
Audit: stop deadlock from signals under load
Audit: save audit_backlog_limit audit messages in case auditd comes back
Audit: collect sessionid in netlink messages
Audit: end printk with newline
Diffstat (limited to 'kernel/audit.c')
-rw-r--r-- | kernel/audit.c | 249 |
1 files changed, 173 insertions, 76 deletions
diff --git a/kernel/audit.c b/kernel/audit.c index a7b1608..b7d3709 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -126,6 +126,8 @@ static int audit_freelist_count; static LIST_HEAD(audit_freelist); static struct sk_buff_head audit_skb_queue; +/* queue of skbs to send to auditd when/if it comes back */ +static struct sk_buff_head audit_skb_hold_queue; static struct task_struct *kauditd_task; static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); @@ -154,6 +156,11 @@ struct audit_buffer { gfp_t gfp_mask; }; +struct audit_reply { + int pid; + struct sk_buff *skb; +}; + static void audit_set_pid(struct audit_buffer *ab, pid_t pid) { if (ab) { @@ -252,14 +259,15 @@ void audit_log_lost(const char *message) } static int audit_log_config_change(char *function_name, int new, int old, - uid_t loginuid, u32 sid, int allow_changes) + uid_t loginuid, u32 sessionid, u32 sid, + int allow_changes) { 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); + audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new, + old, loginuid, sessionid); if (sid) { char *ctx = NULL; u32 len; @@ -279,7 +287,8 @@ static int audit_log_config_change(char *function_name, int new, int old, } static int audit_do_config_change(char *function_name, int *to_change, - int new, uid_t loginuid, u32 sid) + int new, uid_t loginuid, u32 sessionid, + u32 sid) { int allow_changes, rc = 0, old = *to_change; @@ -290,8 +299,8 @@ static int audit_do_config_change(char *function_name, int *to_change, allow_changes = 1; if (audit_enabled != AUDIT_OFF) { - rc = audit_log_config_change(function_name, new, old, - loginuid, sid, allow_changes); + rc = audit_log_config_change(function_name, new, old, loginuid, + sessionid, sid, allow_changes); if (rc) allow_changes = 0; } @@ -305,26 +314,28 @@ static int audit_do_config_change(char *function_name, int *to_change, return rc; } -static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid) +static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid, + u32 sid) { return audit_do_config_change("audit_rate_limit", &audit_rate_limit, - limit, loginuid, sid); + limit, loginuid, sessionid, sid); } -static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid) +static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid, + u32 sid) { return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, - limit, loginuid, sid); + limit, loginuid, sessionid, sid); } -static int audit_set_enabled(int state, uid_t loginuid, u32 sid) +static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid) { int rc; if (state < AUDIT_OFF || state > AUDIT_LOCKED) return -EINVAL; rc = audit_do_config_change("audit_enabled", &audit_enabled, state, - loginuid, sid); + loginuid, sessionid, sid); if (!rc) audit_ever_enabled |= !!state; @@ -332,7 +343,7 @@ static int audit_set_enabled(int state, uid_t loginuid, u32 sid) return rc; } -static int audit_set_failure(int state, uid_t loginuid, u32 sid) +static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid) { if (state != AUDIT_FAIL_SILENT && state != AUDIT_FAIL_PRINTK @@ -340,7 +351,43 @@ static int audit_set_failure(int state, uid_t loginuid, u32 sid) return -EINVAL; return audit_do_config_change("audit_failure", &audit_failure, state, - loginuid, sid); + loginuid, sessionid, sid); +} + +/* + * Queue skbs to be sent to auditd when/if it comes back. These skbs should + * already have been sent via prink/syslog and so if these messages are dropped + * it is not a huge concern since we already passed the audit_log_lost() + * notification and stuff. This is just nice to get audit messages during + * boot before auditd is running or messages generated while auditd is stopped. + * This only holds messages is audit_default is set, aka booting with audit=1 + * or building your kernel that way. + */ +static void audit_hold_skb(struct sk_buff *skb) +{ + if (audit_default && + skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit) + skb_queue_tail(&audit_skb_hold_queue, skb); + else + kfree_skb(skb); +} + +static void kauditd_send_skb(struct sk_buff *skb) +{ + int err; + /* take a reference in case we can't send it and we want to hold it */ + skb_get(skb); + 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; + /* we might get lucky and get this in the next auditd */ + audit_hold_skb(skb); + } else + /* drop the extra reference if sent ok */ + kfree_skb(skb); } static int kauditd_thread(void *dummy) @@ -349,24 +396,41 @@ static int kauditd_thread(void *dummy) set_freezable(); while (!kthread_should_stop()) { + /* + * if auditd just started drain the queue of messages already + * sent to syslog/printk. remember loss here is ok. we already + * called audit_log_lost() if it didn't go out normally. so the + * race between the skb_dequeue and the next check for audit_pid + * doesn't matter. + * + * if you ever find kauditd to be too slow we can get a perf win + * by doing our own locking and keeping better track if there + * are messages in this queue. I don't see the need now, but + * in 5 years when I want to play with this again I'll see this + * note and still have no friggin idea what i'm thinking today. + */ + if (audit_default && audit_pid) { + skb = skb_dequeue(&audit_skb_hold_queue); + if (unlikely(skb)) { + while (skb && audit_pid) { + kauditd_send_skb(skb); + skb = skb_dequeue(&audit_skb_hold_queue); + } + } + } + skb = skb_dequeue(&audit_skb_queue); wake_up(&audit_backlog_wait); if (skb) { - if (audit_pid) { - 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 { + if (audit_pid) + kauditd_send_skb(skb); + else { if (printk_ratelimit()) - printk(KERN_NOTICE "%s\n", skb->data + - NLMSG_SPACE(0)); + printk(KERN_NOTICE "%s\n", skb->data + NLMSG_SPACE(0)); else audit_log_lost("printk limit exceeded\n"); - kfree_skb(skb); + + audit_hold_skb(skb); } } else { DECLARE_WAITQUEUE(wait, current); @@ -385,13 +449,13 @@ static int kauditd_thread(void *dummy) return 0; } -static int audit_prepare_user_tty(pid_t pid, uid_t loginuid) +static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid) { struct task_struct *tsk; int err; read_lock(&tasklist_lock); - tsk = find_task_by_pid(pid); + tsk = find_task_by_vpid(pid); err = -ESRCH; if (!tsk) goto out; @@ -404,7 +468,7 @@ static int audit_prepare_user_tty(pid_t pid, uid_t loginuid) if (err) goto out; - tty_audit_push_task(tsk, loginuid); + tty_audit_push_task(tsk, loginuid, sessionid); out: read_unlock(&tasklist_lock); return err; @@ -469,6 +533,19 @@ nlmsg_failure: /* Used by NLMSG_PUT */ return NULL; } +static int audit_send_reply_thread(void *arg) +{ + struct audit_reply *reply = (struct audit_reply *)arg; + + mutex_lock(&audit_cmd_mutex); + mutex_unlock(&audit_cmd_mutex); + + /* Ignore failure. It'll only happen if the sender goes away, + because our timeout is set to infinite. */ + netlink_unicast(audit_sock, reply->skb, reply->pid, 0); + kfree(reply); + return 0; +} /** * audit_send_reply - send an audit reply message via netlink * @pid: process id to send reply to @@ -485,14 +562,26 @@ nlmsg_failure: /* Used by NLMSG_PUT */ void audit_send_reply(int pid, int seq, int type, int done, int multi, void *payload, int size) { - struct sk_buff *skb; + struct sk_buff *skb; + struct task_struct *tsk; + struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), + GFP_KERNEL); + + if (!reply) + return; + skb = audit_make_reply(pid, seq, type, done, multi, payload, size); if (!skb) return; - /* 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; + + reply->pid = pid; + reply->skb = skb; + + tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); + if (IS_ERR(tsk)) { + kfree(reply); + kfree_skb(skb); + } } /* @@ -534,7 +623,8 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) } static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type, - u32 pid, u32 uid, uid_t auid, u32 sid) + u32 pid, u32 uid, uid_t auid, u32 ses, + u32 sid) { int rc = 0; char *ctx = NULL; @@ -546,8 +636,8 @@ static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type, } *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); - audit_log_format(*ab, "user pid=%d uid=%u auid=%u", - pid, uid, auid); + audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u", + pid, uid, auid, ses); if (sid) { rc = security_secid_to_secctx(sid, &ctx, &len); if (rc) @@ -570,6 +660,7 @@ 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 */ + u32 sessionid; struct audit_sig_info *sig_data; char *ctx = NULL; u32 len; @@ -591,6 +682,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) pid = NETLINK_CREDS(skb)->pid; uid = NETLINK_CREDS(skb)->uid; loginuid = NETLINK_CB(skb).loginuid; + sessionid = NETLINK_CB(skb).sessionid; sid = NETLINK_CB(skb).sid; seq = nlh->nlmsg_seq; data = NLMSG_DATA(nlh); @@ -613,12 +705,12 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) status_get = (struct audit_status *)data; if (status_get->mask & AUDIT_STATUS_ENABLED) { err = audit_set_enabled(status_get->enabled, - loginuid, sid); + loginuid, sessionid, sid); if (err < 0) return err; } if (status_get->mask & AUDIT_STATUS_FAILURE) { err = audit_set_failure(status_get->failure, - loginuid, sid); + loginuid, sessionid, sid); if (err < 0) return err; } if (status_get->mask & AUDIT_STATUS_PID) { @@ -627,17 +719,17 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (audit_enabled != AUDIT_OFF) audit_log_config_change("audit_pid", new_pid, audit_pid, loginuid, - sid, 1); + sessionid, 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, - loginuid, sid); + loginuid, sessionid, sid); if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) err = audit_set_backlog_limit(status_get->backlog_limit, - loginuid, sid); + loginuid, sessionid, sid); break; case AUDIT_USER: case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: @@ -649,12 +741,13 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err == 1) { err = 0; if (msg_type == AUDIT_USER_TTY) { - err = audit_prepare_user_tty(pid, loginuid); + err = audit_prepare_user_tty(pid, loginuid, + sessionid); if (err) break; } audit_log_common_recv_msg(&ab, msg_type, pid, uid, - loginuid, sid); + loginuid, sessionid, sid); if (msg_type != AUDIT_USER_TTY) audit_log_format(ab, " msg='%.1024s'", @@ -664,8 +757,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) audit_log_format(ab, " msg="); size = nlmsg_len(nlh); - audit_log_n_untrustedstring(ab, size, - data); + audit_log_n_untrustedstring(ab, data, size); } audit_set_pid(ab, pid); audit_log_end(ab); @@ -677,7 +769,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) return -EINVAL; if (audit_enabled == AUDIT_LOCKED) { audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, - uid, loginuid, sid); + uid, loginuid, sessionid, sid); audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); @@ -688,7 +780,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) case AUDIT_LIST: err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, uid, seq, data, nlmsg_len(nlh), - loginuid, sid); + loginuid, sessionid, sid); break; case AUDIT_ADD_RULE: case AUDIT_DEL_RULE: @@ -696,7 +788,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) return -EINVAL; if (audit_enabled == AUDIT_LOCKED) { audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, - uid, loginuid, sid); + uid, loginuid, sessionid, sid); audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); @@ -707,13 +799,13 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) case AUDIT_LIST_RULES: err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, uid, seq, data, nlmsg_len(nlh), - loginuid, sid); + loginuid, sessionid, sid); break; case AUDIT_TRIM: audit_trim_trees(); audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, - uid, loginuid, sid); + uid, loginuid, sessionid, sid); audit_log_format(ab, " op=trim res=1"); audit_log_end(ab); @@ -721,21 +813,21 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) case AUDIT_MAKE_EQUIV: { void *bufp = data; u32 sizes[2]; - size_t len = nlmsg_len(nlh); + size_t msglen = nlmsg_len(nlh); char *old, *new; err = -EINVAL; - if (len < 2 * sizeof(u32)) + if (msglen < 2 * sizeof(u32)) break; memcpy(sizes, bufp, 2 * sizeof(u32)); bufp += 2 * sizeof(u32); - len -= 2 * sizeof(u32); - old = audit_unpack_string(&bufp, &len, sizes[0]); + msglen -= 2 * sizeof(u32); + old = audit_unpack_string(&bufp, &msglen, sizes[0]); if (IS_ERR(old)) { err = PTR_ERR(old); break; } - new = audit_unpack_string(&bufp, &len, sizes[1]); + new = audit_unpack_string(&bufp, &msglen, sizes[1]); if (IS_ERR(new)) { err = PTR_ERR(new); kfree(old); @@ -745,7 +837,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) err = audit_tag_tree(old, new); audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, - uid, loginuid, sid); + uid, loginuid, sessionid, sid); audit_log_format(ab, " op=make_equiv old="); audit_log_untrustedstring(ab, old); @@ -779,7 +871,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) struct task_struct *tsk; read_lock(&tasklist_lock); - tsk = find_task_by_pid(pid); + tsk = find_task_by_vpid(pid); if (!tsk) err = -ESRCH; else { @@ -802,7 +894,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (s->enabled != 0 && s->enabled != 1) return -EINVAL; read_lock(&tasklist_lock); - tsk = find_task_by_pid(pid); + tsk = find_task_by_vpid(pid); if (!tsk) err = -ESRCH; else { @@ -877,6 +969,7 @@ static int __init audit_init(void) audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; skb_queue_head_init(&audit_skb_queue); + skb_queue_head_init(&audit_skb_hold_queue); audit_initialized = 1; audit_enabled = audit_default; audit_ever_enabled |= !!audit_default; @@ -1199,7 +1292,7 @@ void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) * This function will take the passed buf and convert it into a string of * ascii hex digits. The new string is placed onto the skb. */ -void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, +void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, size_t len) { int i, avail, new_len; @@ -1235,8 +1328,8 @@ void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, * 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) +void audit_log_n_string(struct audit_buffer *ab, const char *string, + size_t slen) { int avail, new_len; unsigned char *ptr; @@ -1292,13 +1385,13 @@ int audit_string_contains_control(const char *string, size_t len) * The caller specifies the number of characters in the string to log, which may * or may not be the entire string. */ -void audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, - const char *string) +void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, + size_t len) { if (audit_string_contains_control(string, len)) - audit_log_hex(ab, string, len); + audit_log_n_hex(ab, string, len); else - audit_log_n_string(ab, len, string); + audit_log_n_string(ab, string, len); } /** @@ -1311,7 +1404,7 @@ void audit_log_n_untrustedstring(struct audit_buffer *ab, size_t len, */ void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) { - audit_log_n_untrustedstring(ab, strlen(string), string); + audit_log_n_untrustedstring(ab, string, strlen(string)); } /* This is a helper-function to print the escaped d_path */ @@ -1355,19 +1448,23 @@ void audit_log_end(struct audit_buffer *ab) audit_log_lost("rate limit exceeded"); } else { struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); + nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); + if (audit_pid) { - 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 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"); + } 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_hold_skb(ab->skb); } + ab->skb = NULL; } audit_buffer_free(ab); } |