diff options
Diffstat (limited to 'kernel/auditsc.c')
| -rw-r--r-- | kernel/auditsc.c | 2489 |
1 files changed, 2489 insertions, 0 deletions
diff --git a/kernel/auditsc.c b/kernel/auditsc.c new file mode 100644 index 0000000..2a3f0af --- /dev/null +++ b/kernel/auditsc.c @@ -0,0 +1,2489 @@ +/* auditsc.c -- System-call auditing support + * Handles all system-call specific auditing features. + * + * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. + * Copyright 2005 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2005, 2006 IBM Corporation + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Written by Rickard E. (Rik) Faith <faith@redhat.com> + * + * Many of the ideas implemented here are from Stephen C. Tweedie, + * especially the idea of avoiding a copy by using getname. + * + * The method for actual interception of syscall entry and exit (not in + * this file -- see entry.S) is based on a GPL'd patch written by + * okir@suse.de and Copyright 2003 SuSE Linux AG. + * + * POSIX message queue support added by George Wilson <ltcgcw@us.ibm.com>, + * 2006. + * + * The support of additional filter rules compares (>, <, >=, <=) was + * added by Dustin Kirkland <dustin.kirkland@us.ibm.com>, 2005. + * + * Modified by Amy Griffis <amy.griffis@hp.com> to collect additional + * filesystem information. + * + * Subject and object context labeling support added by <danjones@us.ibm.com> + * and <dustin.kirkland@us.ibm.com> for LSPP certification compliance. + */ + +#include <linux/init.h> +#include <asm/types.h> +#include <asm/atomic.h> +#include <linux/fs.h> +#include <linux/namei.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/mount.h> +#include <linux/socket.h> +#include <linux/mqueue.h> +#include <linux/audit.h> +#include <linux/personality.h> +#include <linux/time.h> +#include <linux/netlink.h> +#include <linux/compiler.h> +#include <asm/unistd.h> +#include <linux/security.h> +#include <linux/list.h> +#include <linux/tty.h> +#include <linux/binfmts.h> +#include <linux/highmem.h> +#include <linux/syscalls.h> +#include <linux/inotify.h> + +#include "audit.h" + +/* AUDIT_NAMES is the number of slots we reserve in the audit_context + * for saving names from getname(). */ +#define AUDIT_NAMES 20 + +/* Indicates that audit should log the full pathname. */ +#define AUDIT_NAME_FULL -1 + +/* no execve audit message should be longer than this (userspace limits) */ +#define MAX_EXECVE_AUDIT_LEN 7500 + +/* number of audit rules */ +int audit_n_rules; + +/* determines whether we collect data for signals sent */ +int audit_signals; + +/* When fs/namei.c:getname() is called, we store the pointer in name and + * we don't let putname() free it (instead we free all of the saved + * pointers at syscall exit time). + * + * Further, in fs/namei.c:path_lookup() we store the inode and device. */ +struct audit_names { + const char *name; + int name_len; /* number of name's characters to log */ + unsigned name_put; /* call __putname() for this name */ + unsigned long ino; + dev_t dev; + umode_t mode; + uid_t uid; + gid_t gid; + dev_t rdev; + u32 osid; +}; + +struct audit_aux_data { + struct audit_aux_data *next; + int type; +}; + +#define AUDIT_AUX_IPCPERM 0 + +/* Number of target pids per aux struct. */ +#define AUDIT_AUX_PIDS 16 + +struct audit_aux_data_mq_open { + struct audit_aux_data d; + int oflag; + mode_t mode; + struct mq_attr attr; +}; + +struct audit_aux_data_mq_sendrecv { + struct audit_aux_data d; + mqd_t mqdes; + size_t msg_len; + unsigned int msg_prio; + struct timespec abs_timeout; +}; + +struct audit_aux_data_mq_notify { + struct audit_aux_data d; + mqd_t mqdes; + struct sigevent notification; +}; + +struct audit_aux_data_mq_getsetattr { + struct audit_aux_data d; + mqd_t mqdes; + struct mq_attr mqstat; +}; + +struct audit_aux_data_ipcctl { + struct audit_aux_data d; + struct ipc_perm p; + unsigned long qbytes; + uid_t uid; + gid_t gid; + mode_t mode; + u32 osid; +}; + +struct audit_aux_data_execve { + struct audit_aux_data d; + int argc; + int envc; + struct mm_struct *mm; +}; + +struct audit_aux_data_socketcall { + struct audit_aux_data d; + int nargs; + unsigned long args[0]; +}; + +struct audit_aux_data_sockaddr { + struct audit_aux_data d; + int len; + char a[0]; +}; + +struct audit_aux_data_fd_pair { + struct audit_aux_data d; + int fd[2]; +}; + +struct audit_aux_data_pids { + struct audit_aux_data d; + pid_t target_pid[AUDIT_AUX_PIDS]; + uid_t target_auid[AUDIT_AUX_PIDS]; + uid_t target_uid[AUDIT_AUX_PIDS]; + unsigned int target_sessionid[AUDIT_AUX_PIDS]; + u32 target_sid[AUDIT_AUX_PIDS]; + char target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN]; + int pid_count; +}; + +struct audit_tree_refs { + struct audit_tree_refs *next; + struct audit_chunk *c[31]; +}; + +/* The per-task audit context. */ +struct audit_context { + int dummy; /* must be the first element */ + int in_syscall; /* 1 if task is in a syscall */ + enum audit_state state; + unsigned int serial; /* serial number for record */ + struct timespec ctime; /* time of syscall entry */ + int major; /* syscall number */ + unsigned long argv[4]; /* syscall arguments */ + int return_valid; /* return code is valid */ + long return_code;/* syscall return code */ + int auditable; /* 1 if record should be written */ + int name_count; + struct audit_names names[AUDIT_NAMES]; + char * filterkey; /* key for rule that triggered record */ + struct path pwd; + struct audit_context *previous; /* For nested syscalls */ + struct audit_aux_data *aux; + struct audit_aux_data *aux_pids; + + /* Save things to print about task_struct */ + pid_t pid, ppid; + uid_t uid, euid, suid, fsuid; + gid_t gid, egid, sgid, fsgid; + unsigned long personality; + int arch; + + pid_t target_pid; + uid_t target_auid; + uid_t target_uid; + unsigned int target_sessionid; + u32 target_sid; + char target_comm[TASK_COMM_LEN]; + + struct audit_tree_refs *trees, *first_trees; + int tree_count; + +#if AUDIT_DEBUG + int put_count; + int ino_count; +#endif +}; + +#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE]) +static inline int open_arg(int flags, int mask) +{ + int n = ACC_MODE(flags); + if (flags & (O_TRUNC | O_CREAT)) + n |= AUDIT_PERM_WRITE; + return n & mask; +} + +static int audit_match_perm(struct audit_context *ctx, int mask) +{ + unsigned n; + if (unlikely(!ctx)) + return 0; + n = ctx->major; + + switch (audit_classify_syscall(ctx->arch, n)) { + case 0: /* native */ + if ((mask & AUDIT_PERM_WRITE) && + audit_match_class(AUDIT_CLASS_WRITE, n)) + return 1; + if ((mask & AUDIT_PERM_READ) && + audit_match_class(AUDIT_CLASS_READ, n)) + return 1; + if ((mask & AUDIT_PERM_ATTR) && + audit_match_class(AUDIT_CLASS_CHATTR, n)) + return 1; + return 0; + case 1: /* 32bit on biarch */ + if ((mask & AUDIT_PERM_WRITE) && + audit_match_class(AUDIT_CLASS_WRITE_32, n)) + return 1; + if ((mask & AUDIT_PERM_READ) && + audit_match_class(AUDIT_CLASS_READ_32, n)) + return 1; + if ((mask & AUDIT_PERM_ATTR) && + audit_match_class(AUDIT_CLASS_CHATTR_32, n)) + return 1; + return 0; + case 2: /* open */ + return mask & ACC_MODE(ctx->argv[1]); + case 3: /* openat */ + return mask & ACC_MODE(ctx->argv[2]); + case 4: /* socketcall */ + return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND); + case 5: /* execve */ + return mask & AUDIT_PERM_EXEC; + default: + return 0; + } +} + +static int audit_match_filetype(struct audit_context *ctx, int which) +{ + unsigned index = which & ~S_IFMT; + mode_t mode = which & S_IFMT; + + if (unlikely(!ctx)) + return 0; + + if (index >= ctx->name_count) + return 0; + if (ctx->names[index].ino == -1) + return 0; + if ((ctx->names[index].mode ^ mode) & S_IFMT) + return 0; + return 1; +} + +/* + * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *; + * ->first_trees points to its beginning, ->trees - to the current end of data. + * ->tree_count is the number of free entries in array pointed to by ->trees. + * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL, + * "empty" becomes (p, p, 31) afterwards. We don't shrink the list (and seriously, + * it's going to remain 1-element for almost any setup) until we free context itself. + * References in it _are_ dropped - at the same time we free/drop aux stuff. + */ + +#ifdef CONFIG_AUDIT_TREE +static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk) +{ + struct audit_tree_refs *p = ctx->trees; + int left = ctx->tree_count; + if (likely(left)) { + p->c[--left] = chunk; + ctx->tree_count = left; + return 1; + } + if (!p) + return 0; + p = p->next; + if (p) { + p->c[30] = chunk; + ctx->trees = p; + ctx->tree_count = 30; + return 1; + } + return 0; +} + +static int grow_tree_refs(struct audit_context *ctx) +{ + struct audit_tree_refs *p = ctx->trees; + ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL); + if (!ctx->trees) { + ctx->trees = p; + return 0; + } + if (p) + p->next = ctx->trees; + else + ctx->first_trees = ctx->trees; + ctx->tree_count = 31; + return 1; +} +#endif + +static void unroll_tree_refs(struct audit_context *ctx, + struct audit_tree_refs *p, int count) +{ +#ifdef CONFIG_AUDIT_TREE + struct audit_tree_refs *q; + int n; + if (!p) { + /* we started with empty chain */ + p = ctx->first_trees; + count = 31; + /* if the very first allocation has failed, nothing to do */ + if (!p) + return; + } + n = count; + for (q = p; q != ctx->trees; q = q->next, n = 31) { + while (n--) { + audit_put_chunk(q->c[n]); + q->c[n] = NULL; + } + } + while (n-- > ctx->tree_count) { + audit_put_chunk(q->c[n]); + q->c[n] = NULL; + } + ctx->trees = p; + ctx->tree_count = count; +#endif +} + +static void free_tree_refs(struct audit_context *ctx) +{ + struct audit_tree_refs *p, *q; + for (p = ctx->first_trees; p; p = q) { + q = p->next; + kfree(p); + } +} + +static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree) +{ +#ifdef CONFIG_AUDIT_TREE + struct audit_tree_refs *p; + int n; + if (!tree) + return 0; + /* full ones */ + for (p = ctx->first_trees; p != ctx->trees; p = p->next) { + for (n = 0; n < 31; n++) + if (audit_tree_match(p->c[n], tree)) + return 1; + } + /* partial */ + if (p) { + for (n = ctx->tree_count; n < 31; n++) + if (audit_tree_match(p->c[n], tree)) + return 1; + } +#endif + return 0; +} + +/* Determine if any context name data matches a rule's watch data */ +/* Compare a task_struct with an audit_rule. Return 1 on match, 0 + * otherwise. */ +static int audit_filter_rules(struct task_struct *tsk, + struct audit_krule *rule, + struct audit_context *ctx, + struct audit_names *name, + enum audit_state *state) +{ + int i, j, need_sid = 1; + u32 sid; + + for (i = 0; i < rule->field_count; i++) { + struct audit_field *f = &rule->fields[i]; + int result = 0; + + switch (f->type) { + case AUDIT_PID: + result = audit_comparator(tsk->pid, f->op, f->val); + break; + case AUDIT_PPID: + if (ctx) { + if (!ctx->ppid) + ctx->ppid = sys_getppid(); + result = audit_comparator(ctx->ppid, f->op, f->val); + } + break; + case AUDIT_UID: + result = audit_comparator(tsk->uid, f->op, f->val); + break; + case AUDIT_EUID: + result = audit_comparator(tsk->euid, f->op, f->val); + break; + case AUDIT_SUID: + result = audit_comparator(tsk->suid, f->op, f->val); + break; + case AUDIT_FSUID: + result = audit_comparator(tsk->fsuid, f->op, f->val); + break; + case AUDIT_GID: + result = audit_comparator(tsk->gid, f->op, f->val); + break; + case AUDIT_EGID: + result = audit_comparator(tsk->egid, f->op, f->val); + break; + case AUDIT_SGID: + result = audit_comparator(tsk->sgid, f->op, f->val); + break; + case AUDIT_FSGID: + result = audit_comparator(tsk->fsgid, f->op, f->val); + break; + case AUDIT_PERS: + result = audit_comparator(tsk->personality, f->op, f->val); + break; + case AUDIT_ARCH: + if (ctx) + result = audit_comparator(ctx->arch, f->op, f->val); + break; + + case AUDIT_EXIT: + if (ctx && ctx->return_valid) + result = audit_comparator(ctx->return_code, f->op, f->val); + break; + case AUDIT_SUCCESS: + if (ctx && ctx->return_valid) { + if (f->val) + result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS); + else + result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE); + } + break; + case AUDIT_DEVMAJOR: + if (name) + result = audit_comparator(MAJOR(name->dev), + f->op, f->val); + else if (ctx) { + for (j = 0; j < ctx->name_count; j++) { + if (audit_comparator(MAJOR(ctx->names[j].dev), f->op, f->val)) { + ++result; + break; + } + } + } + break; + case AUDIT_DEVMINOR: + if (name) + result = audit_comparator(MINOR(name->dev), + f->op, f->val); + else if (ctx) { + for (j = 0; j < ctx->name_count; j++) { + if (audit_comparator(MINOR(ctx->names[j].dev), f->op, f->val)) { + ++result; + break; + } + } + } + break; + case AUDIT_INODE: + if (name) + result = (name->ino == f->val); + else if (ctx) { + for (j = 0; j < ctx->name_count; j++) { + if (audit_comparator(ctx->names[j].ino, f->op, f->val)) { + ++result; + break; + } + } + } + break; + case AUDIT_WATCH: + if (name && rule->watch->ino != (unsigned long)-1) + result = (name->dev == rule->watch->dev && + name->ino == rule->watch->ino); + break; + case AUDIT_DIR: + if (ctx) + result = match_tree_refs(ctx, rule->tree); + break; + case AUDIT_LOGINUID: + result = 0; + if (ctx) + result = audit_comparator(tsk->loginuid, f->op, f->val); + break; + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + /* NOTE: this may return negative values indicating + a temporary error. We simply treat this as a + match for now to avoid losing information that + may be wanted. An error message will also be + logged upon error */ + if (f->lsm_rule) { + if (need_sid) { + security_task_getsecid(tsk, &sid); + need_sid = 0; + } + result = security_audit_rule_match(sid, f->type, + f->op, + f->lsm_rule, + ctx); + } + break; + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + /* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR + also applies here */ + if (f->lsm_rule) { + /* Find files that match */ + if (name) { + result = security_audit_rule_match( + name->osid, f->type, f->op, + f->lsm_rule, ctx); + } else if (ctx) { + for (j = 0; j < ctx->name_count; j++) { + if (security_audit_rule_match( + ctx->names[j].osid, + f->type, f->op, + f->lsm_rule, ctx)) { + ++result; + break; + } + } + } + /* Find ipc objects that match */ + if (ctx) { + struct audit_aux_data *aux; + for (aux = ctx->aux; aux; + aux = aux->next) { + if (aux->type == AUDIT_IPC) { + struct audit_aux_data_ipcctl *axi = (void *)aux; + if (security_audit_rule_match(axi->osid, f->type, f->op, f->lsm_rule, ctx)) { + ++result; + break; + } + } + } + } + } + break; + case AUDIT_ARG0: + case AUDIT_ARG1: + case AUDIT_ARG2: + case AUDIT_ARG3: + if (ctx) + result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val); + break; + case AUDIT_FILTERKEY: + /* ignore this field for filtering */ + result = 1; + break; + case AUDIT_PERM: + result = audit_match_perm(ctx, f->val); + break; + case AUDIT_FILETYPE: + result = audit_match_filetype(ctx, f->val); + break; + } + + if (!result) + return 0; + } + if (rule->filterkey && ctx) + ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC); + switch (rule->action) { + case AUDIT_NEVER: *state = AUDIT_DISABLED; break; + case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; + } + return 1; +} + +/* At process creation time, we can determine if system-call auditing is + * completely disabled for this task. Since we only have the task + * structure at this point, we can only check uid and gid. + */ +static enum audit_state audit_filter_task(struct task_struct *tsk) +{ + struct audit_entry *e; + enum audit_state state; + + rcu_read_lock(); + list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) { + if (audit_filter_rules(tsk, &e->rule, NULL, NULL, &state)) { + rcu_read_unlock(); + return state; + } + } + rcu_read_unlock(); + return AUDIT_BUILD_CONTEXT; +} + +/* At syscall entry and exit time, this filter is called if the + * audit_state is not low enough that auditing cannot take place, but is + * also not high enough that we already know we have to write an audit + * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT). + */ +static enum audit_state audit_filter_syscall(struct task_struct *tsk, + struct audit_context *ctx, + struct list_head *list) +{ + struct audit_entry *e; + enum audit_state state; + + if (audit_pid && tsk->tgid == audit_pid) + return AUDIT_DISABLED; + + rcu_read_lock(); + if (!list_empty(list)) { + int word = AUDIT_WORD(ctx->major); + int bit = AUDIT_BIT(ctx->major); + + list_for_each_entry_rcu(e, list, list) { + if ((e->rule.mask[word] & bit) == bit && + audit_filter_rules(tsk, &e->rule, ctx, NULL, + &state)) { + rcu_read_unlock(); + return state; + } + } + } + rcu_read_unlock(); + return AUDIT_BUILD_CONTEXT; +} + +/* At syscall exit time, this filter is called if any audit_names[] have been + * collected during syscall processing. We only check rules in sublists at hash + * buckets applicable to the inode numbers in audit_names[]. + * Regarding audit_state, same rules apply as for audit_filter_syscall(). + */ +enum audit_state audit_filter_inodes(struct task_struct *tsk, + struct audit_context *ctx) +{ + int i; + struct audit_entry *e; + enum audit_state state; + + if (audit_pid && tsk->tgid == audit_pid) + return AUDIT_DISABLED; + + rcu_read_lock(); + for (i = 0; i < ctx->name_count; i++) { + int word = AUDIT_WORD(ctx->major); + int bit = AUDIT_BIT(ctx->major); + struct audit_names *n = &ctx->names[i]; + int h = audit_hash_ino((u32)n->ino); + struct list_head *list = &audit_inode_hash[h]; + + if (list_empty(list)) + continue; + + list_for_each_entry_rcu(e, list, list) { + if ((e->rule.mask[word] & bit) == bit && + audit_filter_rules(tsk, &e->rule, ctx, n, &state)) { + rcu_read_unlock(); + return state; + } + } + } + rcu_read_unlock(); + return AUDIT_BUILD_CONTEXT; +} + +void audit_set_auditable(struct audit_context *ctx) +{ + ctx->auditable = 1; +} + +static inline struct audit_context *audit_get_context(struct task_struct *tsk, + int return_valid, + int return_code) +{ + struct audit_context *context = tsk->audit_context; + + if (likely(!context)) + return NULL; + context->return_valid = return_valid; + + /* + * we need to fix up the return code in the audit logs if the actual + * return codes are later going to be fixed up by the arch specific + * signal handlers + * + * This is actually a test for: + * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) || + * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK) + * + * but is faster than a bunch of || + */ + if (unlikely(return_code <= -ERESTARTSYS) && + (return_code >= -ERESTART_RESTARTBLOCK) && + (return_code != -ENOIOCTLCMD)) + context->return_code = -EINTR; + else + context->return_code = return_code; + + if (context->in_syscall && !context->dummy && !context->auditable) { + enum audit_state state; + + state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]); + if (state == AUDIT_RECORD_CONTEXT) { + context->auditable = 1; + goto get_context; + } + + state = audit_filter_inodes(tsk, context); + if (state == AUDIT_RECORD_CONTEXT) + context->auditable = 1; + + } + +get_context: + + tsk->audit_context = NULL; + return context; +} + +static inline void audit_free_names(struct audit_context *context) +{ + int i; + +#if AUDIT_DEBUG == 2 + if (context->auditable + ||context->put_count + context->ino_count != context->name_count) { + printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d" + " name_count=%d put_count=%d" + " ino_count=%d [NOT freeing]\n", + __FILE__, __LINE__, + context->serial, context->major, context->in_syscall, + context->name_count, context->put_count, + context->ino_count); + for (i = 0; i < context->name_count; i++) { + printk(KERN_ERR "names[%d] = %p = %s\n", i, + context->names[i].name, + context->names[i].name ?: "(null)"); + } + dump_stack(); + return; + } +#endif +#if AUDIT_DEBUG + context->put_count = 0; + context->ino_count = 0; +#endif + + for (i = 0; i < context->name_count; i++) { + if (context->names[i].name && context->names[i].name_put) + __putname(context->names[i].name); + } + context->name_count = 0; + path_put(&context->pwd); + context->pwd.dentry = NULL; + context->pwd.mnt = NULL; +} + +static inline void audit_free_aux(struct audit_context *context) +{ + struct audit_aux_data *aux; + + while ((aux = context->aux)) { + context->aux = aux->next; + kfree(aux); + } + while ((aux = context->aux_pids)) { + context->aux_pids = aux->next; + kfree(aux); + } +} + +static inline void audit_zero_context(struct audit_context *context, + enum audit_state state) +{ + memset(context, 0, sizeof(*context)); + context->state = state; +} + +static inline struct audit_context *audit_alloc_context(enum audit_state state) +{ + struct audit_context *context; + + if (!(context = kmalloc(sizeof(*context), GFP_KERNEL))) + return NULL; + audit_zero_context(context, state); + return context; +} + +/** + * audit_alloc - allocate an audit context block for a task + * @tsk: task + * + * Filter on the task information and allocate a per-task audit context + * if necessary. Doing so turns on system call auditing for the + * specified task. This is called from copy_process, so no lock is + * needed. + */ +int audit_alloc(struct task_struct *tsk) +{ + struct audit_context *context; + enum audit_state state; + + if (likely(!audit_ever_enabled)) + return 0; /* Return if not auditing. */ + + state = audit_filter_task(tsk); + if (likely(state == AUDIT_DISABLED)) + return 0; + + if (!(context = audit_alloc_context(state))) { + audit_log_lost("out of memory in audit_alloc"); + return -ENOMEM; + } + + tsk->audit_context = context; + set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT); + return 0; +} + +static inline void audit_free_context(struct audit_context *context) +{ + struct audit_context *previous; + int count = 0; + + do { + previous = context->previous; + if (previous || (count && count < 10)) { + ++count; + printk(KERN_ERR "audit(:%d): major=%d name_count=%d:" + " freeing multiple contexts (%d)\n", + context->serial, context->major, + context->name_count, count); + } + audit_free_names(context); + unroll_tree_refs(context, NULL, 0); + free_tree_refs(context); + audit_free_aux(context); + kfree(context->filterkey); + kfree(context); + context = previous; + } while (context); + if (count >= 10) + printk(KERN_ERR "audit: freed %d contexts\n", count); +} + +void audit_log_task_context(struct audit_buffer *ab) +{ + char *ctx = NULL; + unsigned len; + int error; + u32 sid; + + security_task_getsecid(current, &sid); + if (!sid) + return; + + error = security_secid_to_secctx(sid, &ctx, &len); + if (error) { + if (error != -EINVAL) + goto error_path; + return; + } + + audit_log_format(ab, " subj=%s", ctx); + security_release_secctx(ctx, len); + return; + +error_path: + audit_panic("error in audit_log_task_context"); + return; +} + +EXPORT_SYMBOL(audit_log_task_context); + +static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) +{ + char name[sizeof(tsk->comm)]; + struct mm_struct *mm = tsk->mm; + struct vm_area_struct *vma; + + /* tsk == current */ + + get_task_comm(name, tsk); + audit_log_format(ab, " comm="); + audit_log_untrustedstring(ab, name); + + if (mm) { + down_read(&mm->mmap_sem); + vma = mm->mmap; + while (vma) { + if ((vma->vm_flags & VM_EXECUTABLE) && + vma->vm_file) { + audit_log_d_path(ab, "exe=", + &vma->vm_file->f_path); + break; + } + vma = vma->vm_next; + } + up_read(&mm->mmap_sem); + } + audit_log_task_context(ab); +} + +static int audit_log_pid_context(struct audit_context *context, pid_t pid, + uid_t auid, uid_t uid, unsigned int sessionid, + u32 sid, char *comm) +{ + struct audit_buffer *ab; + char *ctx = NULL; + u32 len; + int rc = 0; + + ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID); + if (!ab) + return rc; + + audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, auid, + uid, sessionid); + if (security_secid_to_secctx(sid, &ctx, &len)) { + audit_log_format(ab, " obj=(none)"); + rc = 1; + } else { + audit_log_format(ab, " obj=%s", ctx); + security_release_secctx(ctx, len); + } + audit_log_format(ab, " ocomm="); + audit_log_untrustedstring(ab, comm); + audit_log_end(ab); + + return rc; +} + +/* + * to_send and len_sent accounting are very loose estimates. We aren't + * really worried about a hard cap to MAX_EXECVE_AUDIT_LEN so much as being + * within about 500 bytes (next page boundry) + * + * why snprintf? an int is up to 12 digits long. if we just assumed when + * logging that a[%d]= was going to be 16 characters long we would be wasting + * space in every audit message. In one 7500 byte message we can log up to + * about 1000 min size arguments. That comes down to about 50% waste of space + * if we didn't do the snprintf to find out how long arg_num_len was. + */ +static int audit_log_single_execve_arg(struct audit_context *context, + struct audit_buffer **ab, + int arg_num, + size_t *len_sent, + const char __user *p, + char *buf) +{ + char arg_num_len_buf[12]; + const char __user *tmp_p = p; + /* how many digits are in arg_num? 3 is the length of a=\n */ + size_t arg_num_len = snprintf(arg_num_len_buf, 12, "%d", arg_num) + 3; + size_t len, len_left, to_send; + size_t max_execve_audit_len = MAX_EXECVE_AUDIT_LEN; + unsigned int i, has_cntl = 0, too_long = 0; + int ret; + + /* strnlen_user includes the null we don't want to send */ + len_left = len = strnlen_user(p, MAX_ARG_STRLEN) - 1; + + /* + * We just created this mm, if we can't find the strings + * we just copied into it something is _very_ wrong. Similar + * for strings that are too long, we should not have created + * any. + */ + if (unlikely((len == -1) || len > MAX_ARG_STRLEN - 1)) { + WARN_ON(1); + send_sig(SIGKILL, current, 0); + return -1; + } + + /* walk the whole argument looking for non-ascii chars */ + do { + if (len_left > MAX_EXECVE_AUDIT_LEN) + to_send = MAX_EXECVE_AUDIT_LEN; + else + to_send = len_left; + ret = copy_from_user(buf, tmp_p, to_send); + /* + * There is no reason for this copy to be short. We just + * copied them here, and the mm hasn't been exposed to user- + * space yet. + */ + if (ret) { + WARN_ON(1); + send_sig(SIGKILL, current, 0); + return -1; + } + buf[to_send] = '\0'; + has_cntl = audit_string_contains_control(buf, to_send); + if (has_cntl) { + /* + * hex messages get logged as 2 bytes, so we can only + * send half as much in each message + */ + max_execve_audit_len = MAX_EXECVE_AUDIT_LEN / 2; + break; + } + len_left -= to_send; + tmp_p += to_send; + } while (len_left > 0); + + len_left = len; + + if (len > max_execve_audit_len) + too_long = 1; + + /* rewalk the argument actually logging the message */ + for (i = 0; len_left > 0; i++) { + int room_left; + + if (len_left > max_execve_audit_len) + to_send = max_execve_audit_len; + else + to_send = len_left; + + /* do we have space left to send this argument in this ab? */ + room_left = MAX_EXECVE_AUDIT_LEN - arg_num_len - *len_sent; + if (has_cntl) + room_left -= (to_send * 2); + else + room_left -= to_send; + if (room_left < 0) { + *len_sent = 0; + audit_log_end(*ab); + *ab = audit_log_start(context, GFP_KERNEL, AUDIT_EXECVE); + if (!*ab) + return 0; + } + + /* + * first record needs to say how long the original string was + * so we can be sure nothing was lost. + */ + if ((i == 0) && (too_long)) + audit_log_format(*ab, "a%d_len=%zu ", arg_num, + has_cntl ? 2*len : len); + + /* + * normally arguments are small enough to fit and we already + * filled buf above when we checked for control characters + * so don't bother with another copy_from_user + */ + if (len >= max_execve_audit_len) + ret = copy_from_user(buf, p, to_send); + else + ret = 0; + if (ret) { + WARN_ON(1); + send_sig(SIGKILL, current, 0); + return -1; + } + buf[to_send] = '\0'; + + /* actually log it */ + audit_log_format(*ab, "a%d", arg_num); + if (too_long) + audit_log_format(*ab, "[%d]", i); + audit_log_format(*ab, "="); + if (has_cntl) + audit_log_n_hex(*ab, buf, to_send); + else + audit_log_format(*ab, "\"%s\"", buf); + audit_log_format(*ab, "\n"); + + p += to_send; + len_left -= to_send; + *len_sent += arg_num_len; + if (has_cntl) + *len_sent += to_send * 2; + else + *len_sent += to_send; + } + /* include the null we didn't log */ + return len + 1; +} + +static void audit_log_execve_info(struct audit_context *context, + struct audit_buffer **ab, + struct audit_aux_data_execve *axi) +{ + int i; + size_t len, len_sent = 0; + const char __user *p; + char *buf; + + if (axi->mm != current->mm) + return; /* execve failed, no additional info */ + + p = (const char __user *)axi->mm->arg_start; + + audit_log_format(*ab, "argc=%d ", axi->argc); + + /* + * we need some kernel buffer to hold the userspace args. Just + * allocate one big one rather than allocating one of the right size + * for every single argument inside audit_log_single_execve_arg() + * should be <8k allocation so should be pretty safe. + */ + buf = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL); + if (!buf) { + audit_panic("out of memory for argv string\n"); + return; + } + + for (i = 0; i < axi->argc; i++) { + len = audit_log_single_execve_arg(context, ab, i, + &len_sent, p, buf); + if (len <= 0) + break; + p += len; + } + kfree(buf); +} + +static void audit_log_exit(struct audit_context *context, struct task_struct *tsk) +{ + int i, call_panic = 0; + struct audit_buffer *ab; + struct audit_aux_data *aux; + const char *tty; + + /* tsk == current */ + context->pid = tsk->pid; + if (!context->ppid) + context->ppid = sys_getppid(); + context->uid = tsk->uid; + context->gid = tsk->gid; + context->euid = tsk->euid; + context->suid = tsk->suid; + context->fsuid = tsk->fsuid; + context->egid = tsk->egid; + context->sgid = tsk->sgid; + context->fsgid = tsk->fsgid; + context->personality = tsk->personality; + + ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL); + if (!ab) + return; /* audit_panic has been called */ + audit_log_format(ab, "arch=%x syscall=%d", + context->arch, context->major); + if (context->personality != PER_LINUX) + audit_log_format(ab, " per=%lx", context->personality); + if (context->return_valid) + audit_log_format(ab, " success=%s exit=%ld", + (context->return_valid==AUDITSC_SUCCESS)?"yes":"no", + context->return_code); + + spin_lock_irq(&tsk->sighand->siglock); + if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) + tty = tsk->signal->tty->name; + else + tty = "(none)"; + spin_unlock_irq(&tsk->sighand->siglock); + + audit_log_format(ab, + " a0=%lx a1=%lx a2=%lx a3=%lx items=%d" + " ppid=%d pid=%d auid=%u uid=%u gid=%u" + " euid=%u suid=%u fsuid=%u" + " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", + context->argv[0], + context->argv[1], + context->argv[2], + context->argv[3], + context->name_count, + context->ppid, + context->pid, + tsk->loginuid, + context->uid, + context->gid, + context->euid, context->suid, context->fsuid, + context->egid, context->sgid, context->fsgid, tty, + tsk->sessionid); + + + audit_log_task_info(ab, tsk); + if (context->filterkey) { + audit_log_format(ab, " key="); + audit_log_untrustedstring(ab, context->filterkey); + } else + audit_log_format(ab, " key=(null)"); + audit_log_end(ab); + + for (aux = context->aux; aux; aux = aux->next) { + + ab = audit_log_start(context, GFP_KERNEL, aux->type); + if (!ab) + continue; /* audit_panic has been called */ + + switch (aux->type) { + case AUDIT_MQ_OPEN: { + struct audit_aux_data_mq_open *axi = (void *)aux; + audit_log_format(ab, + "oflag=0x%x mode=%#o mq_flags=0x%lx mq_maxmsg=%ld " + "mq_msgsize=%ld mq_curmsgs=%ld", + axi->oflag, axi->mode, axi->attr.mq_flags, + axi->attr.mq_maxmsg, axi->attr.mq_msgsize, + axi->attr.mq_curmsgs); + break; } + + case AUDIT_MQ_SENDRECV: { + struct audit_aux_data_mq_sendrecv *axi = (void *)aux; + audit_log_format(ab, + "mqdes=%d msg_len=%zd msg_prio=%u " + "abs_timeout_sec=%ld abs_timeout_nsec=%ld", + axi->mqdes, axi->msg_len, axi->msg_prio, + axi->abs_timeout.tv_sec, axi->abs_timeout.tv_nsec); + break; } + + case AUDIT_MQ_NOTIFY: { + struct audit_aux_data_mq_notify *axi = (void *)aux; + audit_log_format(ab, + "mqdes=%d sigev_signo=%d", + axi->mqdes, + axi->notification.sigev_signo); + break; } + + case AUDIT_MQ_GETSETATTR: { + struct audit_aux_data_mq_getsetattr *axi = (void *)aux; + audit_log_format(ab, + "mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld " + "mq_curmsgs=%ld ", + axi->mqdes, + axi->mqstat.mq_flags, axi->mqstat.mq_maxmsg, + axi->mqstat.mq_msgsize, axi->mqstat.mq_curmsgs); + break; } + + case AUDIT_IPC: { + struct audit_aux_data_ipcctl *axi = (void *)aux; + audit_log_format(ab, + "ouid=%u ogid=%u mode=%#o", + axi->uid, axi->gid, axi->mode); + if (axi->osid != 0) { + char *ctx = NULL; + u32 len; + if (security_secid_to_secctx( + axi->osid, &ctx, &len)) { + audit_log_format(ab, " osid=%u", + axi->osid); + call_panic = 1; + } else { + audit_log_format(ab, " obj=%s", ctx); + security_release_secctx(ctx, len); + } + } + break; } + + case AUDIT_IPC_SET_PERM: { + struct audit_aux_data_ipcctl *axi = (void *)aux; + audit_log_format(ab, + "qbytes=%lx ouid=%u ogid=%u mode=%#o", + axi->qbytes, axi->uid, axi->gid, axi->mode); + break; } + + case AUDIT_EXECVE: { + struct audit_aux_data_execve *axi = (void *)aux; + audit_log_execve_info(context, &ab, axi); + break; } + + case AUDIT_SOCKETCALL: { + struct audit_aux_data_socketcall *axs = (void *)aux; + audit_log_format(ab, "nargs=%d", axs->nargs); + for (i=0; i<axs->nargs; i++) + audit_log_format(ab, " a%d=%lx", i, axs->args[i]); + break; } + + case AUDIT_SOCKADDR: { + struct audit_aux_data_sockaddr *axs = (void *)aux; + + audit_log_format(ab, "saddr="); + audit_log_n_hex(ab, axs->a, axs->len); + break; } + + case AUDIT_FD_PAIR: { + struct audit_aux_data_fd_pair *axs = (void *)aux; + audit_log_format(ab, "fd0=%d fd1=%d", axs->fd[0], axs->fd[1]); + break; } + + } + audit_log_end(ab); + } + + for (aux = context->aux_pids; aux; aux = aux->next) { + struct audit_aux_data_pids *axs = (void *)aux; + + for (i = 0; i < axs->pid_count; i++) + if (audit_log_pid_context(context, axs->target_pid[i], + axs->target_auid[i], + axs->target_uid[i], + axs->target_sessionid[i], + axs->target_sid[i], + axs->target_comm[i])) + call_panic = 1; + } + + if (context->target_pid && + audit_log_pid_context(context, context->target_pid, + context->target_auid, context->target_uid, + context->target_sessionid, + context->target_sid, context->target_comm)) + call_panic = 1; + + if (context->pwd.dentry && context->pwd.mnt) { + ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD); + if (ab) { + audit_log_d_path(ab, "cwd=", &context->pwd); + audit_log_end(ab); + } + } + for (i = 0; i < context->name_count; i++) { + struct audit_names *n = &context->names[i]; + + ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); + if (!ab) + continue; /* audit_panic has been called */ + + audit_log_format(ab, "item=%d", i); + + if (n->name) { + switch(n->name_len) { + case AUDIT_NAME_FULL: + /* log the full path */ + audit_log_format(ab, " name="); + audit_log_untrustedstring(ab, n->name); + break; + case 0: + /* name was specified as a relative path and the + * directory component is the cwd */ + audit_log_d_path(ab, " name=", &context->pwd); + break; + default: + /* log the name's directory component */ + audit_log_format(ab, " name="); + audit_log_n_untrustedstring(ab, n->name, + n->name_len); + } + } else + audit_log_format(ab, " name=(null)"); + + if (n->ino != (unsigned long)-1) { + audit_log_format(ab, " inode=%lu" + " dev=%02x:%02x mode=%#o" + " ouid=%u ogid=%u rdev=%02x:%02x", + n->ino, + MAJOR(n->dev), + MINOR(n->dev), + n->mode, + n->uid, + n->gid, + MAJOR(n->rdev), + MINOR(n->rdev)); + } + if (n->osid != 0) { + char *ctx = NULL; + u32 len; + if (security_secid_to_secctx( + n->osid, &ctx, &len)) { + audit_log_format(ab, " osid=%u", n->osid); + call_panic = 2; + } else { + audit_log_format(ab, " obj=%s", ctx); + security_release_secctx(ctx, len); + } + } + + audit_log_end(ab); + } + + /* Send end of event record to help user space know we are finished */ + ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE); + if (ab) + audit_log_end(ab); + if (call_panic) + audit_panic("error converting sid to string"); +} + +/** + * audit_free - free a per-task audit context + * @tsk: task whose audit context block to free + * + * Called from copy_process and do_exit + */ +void audit_free(struct task_struct *tsk) +{ + struct audit_context *context; + + context = audit_get_context(tsk, 0, 0); + if (likely(!context)) + return; + + /* Check for system calls that do not go through the exit + * function (e.g., exit_group), then free context block. + * We use GFP_ATOMIC here because we might be doing this + * in the context of the idle thread */ + /* that can happen only if we are called from do_exit() */ + if (context->in_syscall && context->auditable) + audit_log_exit(context, tsk); + + audit_free_context(context); +} + +/** + * audit_syscall_entry - fill in an audit record at syscall entry + * @arch: architecture type + * @major: major syscall type (function) + * @a1: additional syscall register 1 + * @a2: additional syscall register 2 + * @a3: additional syscall register 3 + * @a4: additional syscall register 4 + * + * Fill in audit context at syscall entry. This only happens if the + * audit context was created when the task was created and the state or + * filters demand the audit context be built. If the state from the + * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT, + * then the record will be written at syscall exit time (otherwise, it + * will only be written if another part of the kernel requests that it + * be written). + */ +void audit_syscall_entry(int arch, int major, + unsigned long a1, unsigned long a2, + unsigned long a3, unsigned long a4) +{ + struct task_struct *tsk = current; + struct audit_context *context = tsk->audit_context; + enum audit_state state; + + if (unlikely(!context)) + return; + + /* + * This happens only on certain architectures that make system + * calls in kernel_thread via the entry.S interface, instead of + * with direct calls. (If you are porting to a new + * architecture, hitting this condition can indicate that you + * got the _exit/_leave calls backward in entry.S.) + * + * i386 no + * x86_64 no + * ppc64 yes (see arch/powerpc/platforms/iseries/misc.S) + * + * This also happens with vm86 emulation in a non-nested manner + * (entries without exits), so this case must be caught. + */ + if (context->in_syscall) { + struct audit_context *newctx; + +#if AUDIT_DEBUG + printk(KERN_ERR + "audit(:%d) pid=%d in syscall=%d;" + " entering syscall=%d\n", + context->serial, tsk->pid, context->major, major); +#endif + newctx = audit_alloc_context(context->state); + if (newctx) { + newctx->previous = context; + context = newctx; + tsk->audit_context = newctx; + } else { + /* If we can't alloc a new context, the best we + * can do is to leak memory (any pending putname + * will be lost). The only other alternative is + * to abandon auditing. */ + audit_zero_context(context, context->state); + } + } + BUG_ON(context->in_syscall || context->name_count); + + if (!audit_enabled) + return; + + context->arch = arch; + context->major = major; + context->argv[0] = a1; + context->argv[1] = a2; + context->argv[2] = a3; + context->argv[3] = a4; + + state = context->state; + context->dummy = !audit_n_rules; + if (!context->dummy && (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT)) + state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]); + if (likely(state == AUDIT_DISABLED)) + return; + + context->serial = 0; + context->ctime = CURRENT_TIME; + context->in_syscall = 1; + context->auditable = !!(state == AUDIT_RECORD_CONTEXT); + context->ppid = 0; +} + +void audit_finish_fork(struct task_struct *child) +{ + struct audit_context *ctx = current->audit_context; + struct audit_context *p = child->audit_context; + if (!p || !ctx || !ctx->auditable) + return; + p->arch = ctx->arch; + p->major = ctx->major; + memcpy(p->argv, ctx->argv, sizeof(ctx->argv)); + p->ctime = ctx->ctime; + p->dummy = ctx->dummy; + p->auditable = ctx->auditable; + p->in_syscall = ctx->in_syscall; + p->filterkey = kstrdup(ctx->filterkey, GFP_KERNEL); + p->ppid = current->pid; +} + +/** + * audit_syscall_exit - deallocate audit context after a system call + * @valid: success/failure flag + * @return_code: syscall return value + * + * Tear down after system call. If the audit context has been marked as + * auditable (either because of the AUDIT_RECORD_CONTEXT state from + * filtering, or because some other part of the kernel write an audit + * message), then write out the syscall information. In call cases, + * free the names stored from getname(). + */ +void audit_syscall_exit(int valid, long return_code) +{ + struct task_struct *tsk = current; + struct audit_context *context; + + context = audit_get_context(tsk, valid, return_code); + + if (likely(!context)) + return; + + if (context->in_syscall && context->auditable) + audit_log_exit(context, tsk); + + context->in_syscall = 0; + context->auditable = 0; + + if (context->previous) { + struct audit_context *new_context = context->previous; + context->previous = NULL; + audit_free_context(context); + tsk->audit_context = new_context; + } else { + audit_free_names(context); + unroll_tree_refs(context, NULL, 0); + audit_free_aux(context); + context->aux = NULL; + context->aux_pids = NULL; + context->target_pid = 0; + context->target_sid = 0; + kfree(context->filterkey); + context->filterkey = NULL; + tsk->audit_context = context; + } +} + +static inline void handle_one(const struct inode *inode) +{ +#ifdef CONFIG_AUDIT_TREE + struct audit_context *context; + struct audit_tree_refs *p; + struct audit_chunk *chunk; + int count; + if (likely(list_empty(&inode->inotify_watches))) + return; + context = current->audit_context; + p = context->trees; + count = context->tree_count; + rcu_read_lock(); + chunk = audit_tree_lookup(inode); + rcu_read_unlock(); + if (!chunk) + return; + if (likely(put_tree_ref(context, chunk))) + return; + if (unlikely(!grow_tree_refs(context))) { + printk(KERN_WARNING "out of memory, audit has lost a tree reference\n"); + audit_set_auditable(context); + audit_put_chunk(chunk); + unroll_tree_refs(context, p, count); + return; + } + put_tree_ref(context, chunk); +#endif +} + +static void handle_path(const struct dentry *dentry) +{ +#ifdef CONFIG_AUDIT_TREE + struct audit_context *context; + struct audit_tree_refs *p; + const struct dentry *d, *parent; + struct audit_chunk *drop; + unsigned long seq; + int count; + + context = current->audit_context; + p = context->trees; + count = context->tree_count; +retry: + drop = NULL; + d = dentry; + rcu_read_lock(); + seq = read_seqbegin(&rename_lock); + for(;;) { + struct inode *inode = d->d_inode; + if (inode && unlikely(!list_empty(&inode->inotify_watches))) { + struct audit_chunk *chunk; + chunk = audit_tree_lookup(inode); + if (chunk) { + if (unlikely(!put_tree_ref(context, chunk))) { + drop = chunk; + break; + } + } + } + parent = d->d_parent; + if (parent == d) + break; + d = parent; + } + if (unlikely(read_seqretry(&rename_lock, seq) || drop)) { /* in this order */ + rcu_read_unlock(); + if (!drop) { + /* just a race with rename */ + unroll_tree_refs(context, p, count); + goto retry; + } + audit_put_chunk(drop); + if (grow_tree_refs(context)) { + /* OK, got more space */ + unroll_tree_refs(context, p, count); + goto retry; + } + /* too bad */ + printk(KERN_WARNING + "out of memory, audit has lost a tree reference\n"); + unroll_tree_refs(context, p, count); + audit_set_auditable(context); + return; + } + rcu_read_unlock(); +#endif +} + +/** + * audit_getname - add a name to the list + * @name: name to add + * + * Add a name to the list of audit names for this context. + * Called from fs/namei.c:getname(). + */ +void __audit_getname(const char *name) +{ + struct audit_context *context = current->audit_context; + + if (IS_ERR(name) || !name) + return; + + if (!context->in_syscall) { +#if AUDIT_DEBUG == 2 + printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n", + __FILE__, __LINE__, context->serial, name); + dump_stack(); +#endif + return; + } + BUG_ON(context->name_count >= AUDIT_NAMES); + context->names[context->name_count].name = name; + context->names[context->name_count].name_len = AUDIT_NAME_FULL; + context->names[context->name_count].name_put = 1; + context->names[context->name_count].ino = (unsigned long)-1; + context->names[context->name_count].osid = 0; + ++context->name_count; + if (!context->pwd.dentry) { + read_lock(¤t->fs->lock); + context->pwd = current->fs->pwd; + path_get(¤t->fs->pwd); + read_unlock(¤t->fs->lock); + } + +} + +/* audit_putname - intercept a putname request + * @name: name to intercept and delay for putname + * + * If we have stored the name from getname in the audit context, + * then we delay the putname until syscall exit. + * Called from include/linux/fs.h:putname(). + */ +void audit_putname(const char *name) +{ + struct audit_context *context = current->audit_context; + + BUG_ON(!context); + if (!context->in_syscall) { +#if AUDIT_DEBUG == 2 + printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n", + __FILE__, __LINE__, context->serial, name); + if (context->name_count) { + int i; + for (i = 0; i < context->name_count; i++) + printk(KERN_ERR "name[%d] = %p = %s\n", i, + context->names[i].name, + context->names[i].name ?: "(null)"); + } +#endif + __putname(name); + } +#if AUDIT_DEBUG + else { + ++context->put_count; + if (context->put_count > context->name_count) { + printk(KERN_ERR "%s:%d(:%d): major=%d" + " in_syscall=%d putname(%p) name_count=%d" + " put_count=%d\n", + __FILE__, __LINE__, + context->serial, context->major, + context->in_syscall, name, context->name_count, + context->put_count); + dump_stack(); + } + } +#endif +} + +static int audit_inc_name_count(struct audit_context *context, + const struct inode *inode) +{ + if (context->name_count >= AUDIT_NAMES) { + if (inode) + printk(KERN_DEBUG "name_count maxed, losing inode data: " + "dev=%02x:%02x, inode=%lu\n", + MAJOR(inode->i_sb->s_dev), + MINOR(inode->i_sb->s_dev), + inode->i_ino); + + else + printk(KERN_DEBUG "name_count maxed, losing inode data\n"); + return 1; + } + context->name_count++; +#if AUDIT_DEBUG + context->ino_count++; +#endif + return 0; +} + +/* Copy inode data into an audit_names. */ +static void audit_copy_inode(struct audit_names *name, const struct inode *inode) +{ + name->ino = inode->i_ino; + name->dev = inode->i_sb->s_dev; + name->mode = inode->i_mode; + name->uid = inode->i_uid; + name->gid = inode->i_gid; + name->rdev = inode->i_rdev; + security_inode_getsecid(inode, &name->osid); +} + +/** + * audit_inode - store the inode and device from a lookup + * @name: name being audited + * @dentry: dentry being audited + * + * Called from fs/namei.c:path_lookup(). + */ +void __audit_inode(const char *name, const struct dentry *dentry) +{ + int idx; + struct audit_context *context = current->audit_context; + const struct inode *inode = dentry->d_inode; + + if (!context->in_syscall) + return; + if (context->name_count + && context->names[context->name_count-1].name + && context->names[context->name_count-1].name == name) + idx = context->name_count - 1; + else if (context->name_count > 1 + && context->names[context->name_count-2].name + && context->names[context->name_count-2].name == name) + idx = context->name_count - 2; + else { + /* FIXME: how much do we care about inodes that have no + * associated name? */ + if (audit_inc_name_count(context, inode)) + return; + idx = context->name_count - 1; + context->names[idx].name = NULL; + } + handle_path(dentry); + audit_copy_inode(&context->names[idx], inode); +} + +/** + * audit_inode_child - collect inode info for created/removed objects + * @dname: inode's dentry name + * @dentry: dentry being audited + * @parent: inode of dentry parent + * + * For syscalls that create or remove filesystem objects, audit_inode + * can only collect information for the filesystem object's parent. + * This call updates the audit context with the child's information. + * Syscalls that create a new filesystem object must be hooked after + * the object is created. Syscalls that remove a filesystem object + * must be hooked prior, in order to capture the target inode during + * unsuccessful attempts. + */ +void __audit_inode_child(const char *dname, const struct dentry *dentry, + const struct inode *parent) +{ + int idx; + struct audit_context *context = current->audit_context; + const char *found_parent = NULL, *found_child = NULL; + const struct inode *inode = dentry->d_inode; + int dirlen = 0; + + if (!context->in_syscall) + return; + + if (inode) + handle_one(inode); + /* determine matching parent */ + if (!dname) + goto add_names; + + /* parent is more likely, look for it first */ + for (idx = 0; idx < context->name_count; idx++) { + struct audit_names *n = &context->names[idx]; + + if (!n->name) + continue; + + if (n->ino == parent->i_ino && + !audit_compare_dname_path(dname, n->name, &dirlen)) { + n->name_len = dirlen; /* update parent data in place */ + found_parent = n->name; + goto add_names; + } + } + + /* no matching parent, look for matching child */ + for (idx = 0; idx < context->name_count; idx++) { + struct audit_names *n = &context->names[idx]; + + if (!n->name) + continue; + + /* strcmp() is the more likely scenario */ + if (!strcmp(dname, n->name) || + !audit_compare_dname_path(dname, n->name, &dirlen)) { + if (inode) + audit_copy_inode(n, inode); + else + n->ino = (unsigned long)-1; + found_child = n->name; + goto add_names; + } + } + +add_names: + if (!found_parent) { + if (audit_inc_name_count(context, parent)) + return; + idx = context->name_count - 1; + context->names[idx].name = NULL; + audit_copy_inode(&context->names[idx], parent); + } + + if (!found_child) { + if (audit_inc_name_count(context, inode)) + return; + idx = context->name_count - 1; + + /* Re-use the name belonging to the slot for a matching parent + * directory. All names for this context are relinquished in + * audit_free_names() */ + if (found_parent) { + context->names[idx].name = found_parent; + context->names[idx].name_len = AUDIT_NAME_FULL; + /* don't call __putname() */ + context->names[idx].name_put = 0; + } else { + context->names[idx].name = NULL; + } + + if (inode) + audit_copy_inode(&context->names[idx], inode); + else + context->names[idx].ino = (unsigned long)-1; + } +} +EXPORT_SYMBOL_GPL(__audit_inode_child); + +/** + * auditsc_get_stamp - get local copies of audit_context values + * @ctx: audit_context for the task + * @t: timespec to store time recorded in the audit_context + * @serial: serial value that is recorded in the audit_context + * + * Also sets the context as auditable. + */ +int auditsc_get_stamp(struct audit_context *ctx, + struct timespec *t, unsigned int *serial) +{ + if (!ctx->in_syscall) + return 0; + if (!ctx->serial) + ctx->serial = audit_serial(); + t->tv_sec = ctx->ctime.tv_sec; + t->tv_nsec = ctx->ctime.tv_nsec; + *serial = ctx->serial; + ctx->auditable = 1; + return 1; +} + +/* global counter which is incremented every time something logs in */ +static atomic_t session_id = ATOMIC_INIT(0); + +/** + * audit_set_loginuid - set a task's audit_context loginuid + * @task: task whose audit context is being modified + * @loginuid: loginuid value + * + * Returns 0. + * + * Called (set) from fs/proc/base.c::proc_loginuid_write(). + */ +int audit_set_loginuid(struct task_struct *task, uid_t loginuid) +{ + unsigned int sessionid = atomic_inc_return(&session_id); + struct audit_context *context = task->audit_context; + + if (context && context->in_syscall) { + struct audit_buffer *ab; + + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN); + if (ab) { + audit_log_format(ab, "login pid=%d uid=%u " + "old auid=%u new auid=%u" + " old ses=%u new ses=%u", + task->pid, task->uid, + task->loginuid, loginuid, + task->sessionid, sessionid); + audit_log_end(ab); + } + } + task->sessionid = sessionid; + task->loginuid = loginuid; + return 0; +} + +/** + * __audit_mq_open - record audit data for a POSIX MQ open + * @oflag: open flag + * @mode: mode bits + * @u_attr: queue attributes + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int __audit_mq_open(int oflag, mode_t mode, struct mq_attr __user *u_attr) +{ + struct audit_aux_data_mq_open *ax; + struct audit_context *context = current->audit_context; + + if (!audit_enabled) + return 0; + + if (likely(!context)) + return 0; + + ax = kmalloc(sizeof(*ax), GFP_ATOMIC); + if (!ax) + return -ENOMEM; + + if (u_attr != NULL) { + if (copy_from_user(&ax->attr, u_attr, sizeof(ax->attr))) { + kfree(ax); + return -EFAULT; + } + } else + memset(&ax->attr, 0, sizeof(ax->attr)); + + ax->oflag = oflag; + ax->mode = mode; + + ax->d.type = AUDIT_MQ_OPEN; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +/** + * __audit_mq_timedsend - record audit data for a POSIX MQ timed send + * @mqdes: MQ descriptor + * @msg_len: Message length + * @msg_prio: Message priority + * @u_abs_timeout: Message timeout in absolute time + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_prio, + const struct timespec __user *u_abs_timeout) +{ + struct audit_aux_data_mq_sendrecv *ax; + struct audit_context *context = current->audit_context; + + if (!audit_enabled) + return 0; + + if (likely(!context)) + return 0; + + ax = kmalloc(sizeof(*ax), GFP_ATOMIC); + if (!ax) + return -ENOMEM; + + if (u_abs_timeout != NULL) { + if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) { + kfree(ax); + return -EFAULT; + } + } else + memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout)); + + ax->mqdes = mqdes; + ax->msg_len = msg_len; + ax->msg_prio = msg_prio; + + ax->d.type = AUDIT_MQ_SENDRECV; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +/** + * __audit_mq_timedreceive - record audit data for a POSIX MQ timed receive + * @mqdes: MQ descriptor + * @msg_len: Message length + * @u_msg_prio: Message priority + * @u_abs_timeout: Message timeout in absolute time + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len, + unsigned int __user *u_msg_prio, + const struct timespec __user *u_abs_timeout) +{ + struct audit_aux_data_mq_sendrecv *ax; + struct audit_context *context = current->audit_context; + + if (!audit_enabled) + return 0; + + if (likely(!context)) + return 0; + + ax = kmalloc(sizeof(*ax), GFP_ATOMIC); + if (!ax) + return -ENOMEM; + + if (u_msg_prio != NULL) { + if (get_user(ax->msg_prio, u_msg_prio)) { + kfree(ax); + return -EFAULT; + } + } else + ax->msg_prio = 0; + + if (u_abs_timeout != NULL) { + if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) { + kfree(ax); + return -EFAULT; + } + } else + memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout)); + + ax->mqdes = mqdes; + ax->msg_len = msg_len; + + ax->d.type = AUDIT_MQ_SENDRECV; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +/** + * __audit_mq_notify - record audit data for a POSIX MQ notify + * @mqdes: MQ descriptor + * @u_notification: Notification event + * + * Returns 0 for success or NULL context or < 0 on error. + */ + +int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification) +{ + struct audit_aux_data_mq_notify *ax; + struct audit_context *context = current->audit_context; + + if (!audit_enabled) + return 0; + + if (likely(!context)) + return 0; + + ax = kmalloc(sizeof(*ax), GFP_ATOMIC); + if (!ax) + return -ENOMEM; + + if (u_notification != NULL) { + if (copy_from_user(&ax->notification, u_notification, sizeof(ax->notification))) { + kfree(ax); + return -EFAULT; + } + } else + memset(&ax->notification, 0, sizeof(ax->notification)); + + ax->mqdes = mqdes; + + ax->d.type = AUDIT_MQ_NOTIFY; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +/** + * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute + * @mqdes: MQ descriptor + * @mqstat: MQ flags + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat) +{ + struct audit_aux_data_mq_getsetattr *ax; + struct audit_context *context = current->audit_context; + + if (!audit_enabled) + return 0; + + if (likely(!context)) + return 0; + + ax = kmalloc(sizeof(*ax), GFP_ATOMIC); + if (!ax) + return -ENOMEM; + + ax->mqdes = mqdes; + ax->mqstat = *mqstat; + + ax->d.type = AUDIT_MQ_GETSETATTR; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +/** + * audit_ipc_obj - record audit data for ipc object + * @ipcp: ipc permissions + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int __audit_ipc_obj(struct kern_ipc_perm *ipcp) +{ + struct audit_aux_data_ipcctl *ax; + struct audit_context *context = current->audit_context; + + ax = kmalloc(sizeof(*ax), GFP_ATOMIC); + if (!ax) + return -ENOMEM; + + ax->uid = ipcp->uid; + ax->gid = ipcp->gid; + ax->mode = ipcp->mode; + security_ipc_getsecid(ipcp, &ax->osid); + ax->d.type = AUDIT_IPC; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +/** + * audit_ipc_set_perm - record audit data for new ipc permissions + * @qbytes: msgq bytes + * @uid: msgq user id + * @gid: msgq group id + * @mode: msgq mode (permissions) + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode) +{ + struct audit_aux_data_ipcctl *ax; + struct audit_context *context = current->audit_context; + + ax = kmalloc(sizeof(*ax), GFP_ATOMIC); + if (!ax) + return -ENOMEM; + + ax->qbytes = qbytes; + ax->uid = uid; + ax->gid = gid; + ax->mode = mode; + + ax->d.type = AUDIT_IPC_SET_PERM; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +int audit_bprm(struct linux_binprm *bprm) +{ + struct audit_aux_data_execve *ax; + struct audit_context *context = current->audit_context; + + if (likely(!audit_enabled || !context || context->dummy)) + return 0; + + ax = kmalloc(sizeof(*ax), GFP_KERNEL); + if (!ax) + return -ENOMEM; + + ax->argc = bprm->argc; + ax->envc = bprm->envc; + ax->mm = bprm->mm; + ax->d.type = AUDIT_EXECVE; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + + +/** + * audit_socketcall - record audit data for sys_socketcall + * @nargs: number of args + * @args: args array + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int audit_socketcall(int nargs, unsigned long *args) +{ + struct audit_aux_data_socketcall *ax; + struct audit_context *context = current->audit_context; + + if (likely(!context || context->dummy)) + return 0; + + ax = kmalloc(sizeof(*ax) + nargs * sizeof(unsigned long), GFP_KERNEL); + if (!ax) + return -ENOMEM; + + ax->nargs = nargs; + memcpy(ax->args, args, nargs * sizeof(unsigned long)); + + ax->d.type = AUDIT_SOCKETCALL; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +/** + * __audit_fd_pair - record audit data for pipe and socketpair + * @fd1: the first file descriptor + * @fd2: the second file descriptor + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int __audit_fd_pair(int fd1, int fd2) +{ + struct audit_context *context = current->audit_context; + struct audit_aux_data_fd_pair *ax; + + if (likely(!context)) { + return 0; + } + + ax = kmalloc(sizeof(*ax), GFP_KERNEL); + if (!ax) { + return -ENOMEM; + } + + ax->fd[0] = fd1; + ax->fd[1] = fd2; + + ax->d.type = AUDIT_FD_PAIR; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +/** + * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto + * @len: data length in user space + * @a: data address in kernel space + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int audit_sockaddr(int len, void *a) +{ + struct audit_aux_data_sockaddr *ax; + struct audit_context *context = current->audit_context; + + if (likely(!context || context->dummy)) + return 0; + + ax = kmalloc(sizeof(*ax) + len, GFP_KERNEL); + if (!ax) + return -ENOMEM; + + ax->len = len; + memcpy(ax->a, a, len); + + ax->d.type = AUDIT_SOCKADDR; + ax->d.next = context->aux; + context->aux = (void *)ax; + return 0; +} + +void __audit_ptrace(struct task_struct *t) +{ + struct audit_context *context = current->audit_context; + + context->target_pid = t->pid; + context->target_auid = audit_get_loginuid(t); + context->target_uid = t->uid; + context->target_sessionid = audit_get_sessionid(t); + security_task_getsecid(t, &context->target_sid); + memcpy(context->target_comm, t->comm, TASK_COMM_LEN); +} + +/** + * audit_signal_info - record signal info for shutting down audit subsystem + * @sig: signal value + * @t: task being signaled + * + * If the audit subsystem is being terminated, record the task (pid) + * and uid that is doing that. + */ +int __audit_signal_info(int sig, struct task_struct *t) +{ + struct audit_aux_data_pids *axp; + struct task_struct *tsk = current; + struct audit_context *ctx = tsk->audit_context; + + if (audit_pid && t->tgid == audit_pid) { + if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) { + audit_sig_pid = tsk->pid; + if (tsk->loginuid != -1) + audit_sig_uid = tsk->loginuid; + else + audit_sig_uid = tsk->uid; + security_task_getsecid(tsk, &audit_sig_sid); + } + if (!audit_signals || audit_dummy_context()) + return 0; + } + + /* optimize the common case by putting first signal recipient directly + * in audit_context */ + if (!ctx->target_pid) { + ctx->target_pid = t->tgid; + ctx->target_auid = audit_get_loginuid(t); + ctx->target_uid = t->uid; + ctx->target_sessionid = audit_get_sessionid(t); + security_task_getsecid(t, &ctx->target_sid); + memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN); + return 0; + } + + axp = (void *)ctx->aux_pids; + if (!axp || axp->pid_count == AUDIT_AUX_PIDS) { + axp = kzalloc(sizeof(*axp), GFP_ATOMIC); + if (!axp) + return -ENOMEM; + + axp->d.type = AUDIT_OBJ_PID; + axp->d.next = ctx->aux_pids; + ctx->aux_pids = (void *)axp; + } + BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS); + + axp->target_pid[axp->pid_count] = t->tgid; + axp->target_auid[axp->pid_count] = audit_get_loginuid(t); + axp->target_uid[axp->pid_count] = t->uid; + axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t); + security_task_getsecid(t, &axp->target_sid[axp->pid_count]); + memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN); + axp->pid_count++; + + return 0; +} + +/** + * audit_core_dumps - record information about processes that end abnormally + * @signr: signal value + * + * If a process ends with a core dump, something fishy is going on and we + * should record the event for investigation. + */ +void audit_core_dumps(long signr) +{ + struct audit_buffer *ab; + u32 sid; + uid_t auid = audit_get_loginuid(current); + unsigned int sessionid = audit_get_sessionid(current); + + if (!audit_enabled) + return; + + if (signr == SIGQUIT) /* don't care for those */ + return; + + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND); + audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u", + auid, current->uid, current->gid, sessionid); + security_task_getsecid(current, &sid); + if (sid) { + char *ctx = NULL; + u32 len; + + if (security_secid_to_secctx(sid, &ctx, &len)) + audit_log_format(ab, " ssid=%u", sid); + else { + audit_log_format(ab, " subj=%s", ctx); + security_release_secctx(ctx, len); + } + } + audit_log_format(ab, " pid=%d comm=", current->pid); + audit_log_untrustedstring(ab, current->comm); + audit_log_format(ab, " sig=%ld", signr); + audit_log_end(ab); +} |
