diff options
Diffstat (limited to 'kernel/audit.c')
-rw-r--r-- | kernel/audit.c | 60 |
1 files changed, 45 insertions, 15 deletions
diff --git a/kernel/audit.c b/kernel/audit.c index 09a37581213b..644ab825118b 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -106,6 +106,7 @@ static LIST_HEAD(audit_freelist); static struct sk_buff_head audit_skb_queue; 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 @@ -130,6 +131,7 @@ struct audit_buffer { struct list_head list; struct sk_buff *skb; /* formatted skb ready to send */ struct audit_context *ctx; /* NULL or associated context */ + int gfp_mask; }; static void audit_set_pid(struct audit_buffer *ab, pid_t pid) @@ -226,7 +228,7 @@ static int audit_set_rate_limit(int limit, uid_t loginuid) { int old = audit_rate_limit; audit_rate_limit = limit; - audit_log(NULL, AUDIT_CONFIG_CHANGE, + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, "audit_rate_limit=%d old=%d by auid=%u", audit_rate_limit, old, loginuid); return old; @@ -236,7 +238,7 @@ static int audit_set_backlog_limit(int limit, uid_t loginuid) { int old = audit_backlog_limit; audit_backlog_limit = limit; - audit_log(NULL, AUDIT_CONFIG_CHANGE, + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, "audit_backlog_limit=%d old=%d by auid=%u", audit_backlog_limit, old, loginuid); return old; @@ -248,7 +250,7 @@ static int audit_set_enabled(int state, uid_t loginuid) if (state != 0 && state != 1) return -EINVAL; audit_enabled = state; - audit_log(NULL, AUDIT_CONFIG_CHANGE, + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, "audit_enabled=%d old=%d by auid=%u", audit_enabled, old, loginuid); return old; @@ -262,7 +264,7 @@ static int audit_set_failure(int state, uid_t loginuid) && state != AUDIT_FAIL_PANIC) return -EINVAL; audit_failure = state; - audit_log(NULL, AUDIT_CONFIG_CHANGE, + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, "audit_failure=%d old=%d by auid=%u", audit_failure, old, loginuid); return old; @@ -274,6 +276,7 @@ int kauditd_thread(void *dummy) while (1) { skb = skb_dequeue(&audit_skb_queue); + wake_up(&audit_backlog_wait); if (skb) { if (audit_pid) { int err = netlink_unicast(audit_sock, skb, audit_pid, 0); @@ -417,7 +420,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (status_get->mask & AUDIT_STATUS_PID) { int old = audit_pid; audit_pid = status_get->pid; - audit_log(NULL, AUDIT_CONFIG_CHANGE, + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, "audit_pid=%d old=%d by auid=%u", audit_pid, old, loginuid); } @@ -435,7 +438,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) err = audit_filter_user(pid, msg_type); if (err == 1) { err = 0; - ab = audit_log_start(NULL, msg_type); + ab = audit_log_start(NULL, GFP_KERNEL, msg_type); if (ab) { audit_log_format(ab, "user pid=%d uid=%u auid=%u msg='%.1024s'", @@ -522,7 +525,7 @@ static int __init audit_init(void) skb_queue_head_init(&audit_skb_queue); audit_initialized = 1; audit_enabled = audit_default; - audit_log(NULL, AUDIT_KERNEL, "initialized"); + audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); return 0; } __initcall(audit_init); @@ -586,6 +589,7 @@ static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, goto err; ab->ctx = ctx; + ab->gfp_mask = gfp_mask; nlh = (struct nlmsghdr *)skb_put(ab->skb, NLMSG_SPACE(0)); nlh->nlmsg_type = type; nlh->nlmsg_flags = 0; @@ -644,17 +648,42 @@ static inline void audit_get_stamp(struct audit_context *ctx, * syscall, then the syscall is marked as auditable and an audit record * will be written at syscall exit. If there is no associated task, tsk * should be NULL. */ -struct audit_buffer *audit_log_start(struct audit_context *ctx, int type) + +struct audit_buffer *audit_log_start(struct audit_context *ctx, int gfp_mask, + int type) { struct audit_buffer *ab = NULL; struct timespec t; unsigned int serial; + int reserve; if (!audit_initialized) return NULL; - if (audit_backlog_limit - && skb_queue_len(&audit_skb_queue) > audit_backlog_limit) { + if (gfp_mask & __GFP_WAIT) + reserve = 0; + else + reserve = 5; /* Allow atomic callers to go up to five + entries over the normal backlog limit */ + + while (audit_backlog_limit + && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { + if (gfp_mask & __GFP_WAIT) { + int ret = 1; + /* Wait for auditd to drain the queue a little */ + DECLARE_WAITQUEUE(wait, current); + set_current_state(TASK_INTERRUPTIBLE); + add_wait_queue(&audit_backlog_wait, &wait); + + if (audit_backlog_limit && + skb_queue_len(&audit_skb_queue) > audit_backlog_limit) + ret = schedule_timeout(HZ * 60); + + __set_current_state(TASK_RUNNING); + remove_wait_queue(&audit_backlog_wait, &wait); + if (ret) + continue; + } if (audit_rate_check()) printk(KERN_WARNING "audit: audit_backlog=%d > " @@ -665,7 +694,7 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, int type) return NULL; } - ab = audit_buffer_alloc(ctx, GFP_ATOMIC, type); + ab = audit_buffer_alloc(ctx, gfp_mask, type); if (!ab) { audit_log_lost("out of memory in audit_log_start"); return NULL; @@ -689,7 +718,7 @@ static inline int audit_expand(struct audit_buffer *ab, int extra) { struct sk_buff *skb = ab->skb; int ret = pskb_expand_head(skb, skb_headroom(skb), extra, - GFP_ATOMIC); + ab->gfp_mask); if (ret < 0) { audit_log_lost("out of memory in audit_expand"); return 0; @@ -808,7 +837,7 @@ void audit_log_d_path(struct audit_buffer *ab, const char *prefix, audit_log_format(ab, " %s", prefix); /* We will allow 11 spaces for ' (deleted)' to be appended */ - path = kmalloc(PATH_MAX+11, GFP_KERNEL); + path = kmalloc(PATH_MAX+11, ab->gfp_mask); if (!path) { audit_log_format(ab, "<no memory>"); return; @@ -849,12 +878,13 @@ void audit_log_end(struct audit_buffer *ab) /* Log an audit record. This is a convenience function that calls * audit_log_start, audit_log_vformat, and audit_log_end. It may be * called in any context. */ -void audit_log(struct audit_context *ctx, int type, const char *fmt, ...) +void audit_log(struct audit_context *ctx, int gfp_mask, int type, + const char *fmt, ...) { struct audit_buffer *ab; va_list args; - ab = audit_log_start(ctx, type); + ab = audit_log_start(ctx, gfp_mask, type); if (ab) { va_start(args, fmt); audit_log_vformat(ab, fmt, args); |