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auditsc.c

/* 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/selinux.h>
#include <linux/binfmts.h>
#include <linux/highmem.h>
#include <linux/syscalls.h>
#include <linux/inotify.h>

#include "audit.h"

extern struct list_head audit_filter_list[];

/* 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

/* 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];
      u32               target_sid[AUDIT_AUX_PIDS];
      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 */
      uid_t           loginuid;   /* login uid (identity) */
      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 dentry *       pwd;
      struct vfsmount *   pwdmnt;
      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;
      u32             target_sid;

      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 = 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;
      }
}

/*
 * 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(ctx->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->se_rule) {
                        if (need_sid) {
                              selinux_get_task_sid(tsk, &sid);
                              need_sid = 0;
                        }
                        result = selinux_audit_rule_match(sid, f->type,
                                                          f->op,
                                                          f->se_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->se_rule) {
                        /* Find files that match */
                        if (name) {
                              result = selinux_audit_rule_match(
                                         name->osid, f->type, f->op,
                                         f->se_rule, ctx);
                        } else if (ctx) {
                              for (j = 0; j < ctx->name_count; j++) {
                                    if (selinux_audit_rule_match(
                                          ctx->names[j].osid,
                                          f->type, f->op,
                                          f->se_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 (selinux_audit_rule_match(axi->osid, f->type, f->op, f->se_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;
            }

            if (!result)
                  return 0;
      }
      if (rule->filterkey)
            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;
      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;
      if (context->pwd)
            dput(context->pwd);
      if (context->pwdmnt)
            mntput(context->pwdmnt);
      context->pwd = NULL;
      context->pwdmnt = 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)
{
      uid_t loginuid = context->loginuid;

      memset(context, 0, sizeof(*context));
      context->state      = state;
      context->loginuid   = loginuid;
}

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_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;
      }

                        /* Preserve login uid */
      context->loginuid = -1;
      if (current->audit_context)
            context->loginuid = current->audit_context->loginuid;

      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;

      selinux_get_task_sid(current, &sid);
      if (!sid)
            return;

      error = selinux_sid_to_string(sid, &ctx, &len);
      if (error) {
            if (error != -EINVAL)
                  goto error_path;
            return;
      }

      audit_log_format(ab, " subj=%s", ctx);
      kfree(ctx);
      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.dentry,
                                     vma->vm_file->f_path.mnt);
                        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,
                         u32 sid)
{
      struct audit_buffer *ab;
      char *s = NULL;
      u32 len;
      int rc = 0;

      ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID);
      if (!ab)
            return 1;

      if (selinux_sid_to_string(sid, &s, &len)) {
            audit_log_format(ab, "opid=%d obj=(none)", pid);
            rc = 1;
      } else
            audit_log_format(ab, "opid=%d  obj=%s", pid, s);
      audit_log_end(ab);
      kfree(s);

      return rc;
}

static void audit_log_execve_info(struct audit_buffer *ab,
            struct audit_aux_data_execve *axi)
{
      int i;
      long len, ret;
      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;

      for (i = 0; i < axi->argc; i++, p += len) {
            len = strnlen_user(p, MAX_ARG_STRLEN);
            /*
             * 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 (!len || len > MAX_ARG_STRLEN) {
                  WARN_ON(1);
                  send_sig(SIGKILL, current, 0);
            }

            buf = kmalloc(len, GFP_KERNEL);
            if (!buf) {
                  audit_panic("out of memory for argv string\n");
                  break;
            }

            ret = copy_from_user(buf, p, len);
            /*
             * 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);
            }

            audit_log_format(ab, "a%d=", i);
            audit_log_untrustedstring(ab, buf);
            audit_log_format(ab, "\n");

            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);

      mutex_lock(&tty_mutex);
      read_lock(&tasklist_lock);
      if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
            tty = tsk->signal->tty->name;
      else
            tty = "(none)";
      read_unlock(&tasklist_lock);
      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",
              context->argv[0],
              context->argv[1],
              context->argv[2],
              context->argv[3],
              context->name_count,
              context->ppid,
              context->pid,
              context->loginuid,
              context->uid,
              context->gid,
              context->euid, context->suid, context->fsuid,
              context->egid, context->sgid, context->fsgid, tty);

      mutex_unlock(&tty_mutex);

      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 (selinux_sid_to_string(
                                    axi->osid, &ctx, &len)) {
                              audit_log_format(ab, " osid=%u",
                                          axi->osid);
                              call_panic = 1;
                        } else
                              audit_log_format(ab, " obj=%s", ctx);
                        kfree(ctx);
                  }
                  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(ab, axi);
                  break; }

            case AUDIT_SOCKETCALL: {
                  int i;
                  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_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;
            int i;

            for (i = 0; i < axs->pid_count; i++)
                  if (audit_log_pid_context(context, axs->target_pid[i],
                                      axs->target_sid[i]))
                        call_panic = 1;
      }

      if (context->target_pid &&
          audit_log_pid_context(context, context->target_pid,
                          context->target_sid))
                  call_panic = 1;

      if (context->pwd && context->pwdmnt) {
            ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD);
            if (ab) {
                  audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt);
                  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,
                                     context->pwdmnt);
                        break;
                  default:
                        /* log the name's directory component */
                        audit_log_format(ab, " name=");
                        audit_log_n_untrustedstring(ab, n->name_len,
                                              n->name);
                  }
            } 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 (selinux_sid_to_string(
                        n->osid, &ctx, &len)) {
                        audit_log_format(ab, " osid=%u", n->osid);
                        call_panic = 2;
                  } else
                        audit_log_format(ab, " obj=%s", ctx);
                  kfree(ctx);
            }

            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
 * @tsk: task being audited
 * @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;

      BUG_ON(!context);

      /*
       * 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;
}

/**
 * audit_syscall_exit - deallocate audit context after a system call
 * @tsk: task being audited
 * @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");
            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");
            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) {
            read_lock(&current->fs->lock);
            context->pwd = dget(current->fs->pwd);
            context->pwdmnt = mntget(current->fs->pwdmnt);
            read_unlock(&current->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",
                         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");
            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;
      selinux_get_inode_sid(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.
 */
void auditsc_get_stamp(struct audit_context *ctx,
                   struct timespec *t, unsigned int *serial)
{
      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;
}

/**
 * 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)
{
      struct audit_context *context = task->audit_context;

      if (context) {
            /* Only log if audit is enabled */
            if (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",
                              task->pid, task->uid,
                              context->loginuid, loginuid);
                        audit_log_end(ab);
                  }
            }
            context->loginuid = loginuid;
      }
      return 0;
}

/**
 * audit_get_loginuid - get the loginuid for an audit_context
 * @ctx: the audit_context
 *
 * Returns the context's loginuid or -1 if @ctx is NULL.
 */
uid_t audit_get_loginuid(struct audit_context *ctx)
{
      return ctx ? ctx->loginuid : -1;
}

EXPORT_SYMBOL(audit_get_loginuid);

/**
 * __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;
      selinux_get_ipc_sid(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_argv_kb = 32;

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;

      /*
       * Even though the stack code doesn't limit the arg+env size any more,
       * the audit code requires that _all_ arguments be logged in a single
       * netlink skb. Hence cap it :-(
       */
      if (bprm->argv_len > (audit_argv_kb << 10))
            return -E2BIG;

      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;
      selinux_get_task_sid(t, &context->target_sid);
}

/**
 * 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;
      extern pid_t audit_sig_pid;
      extern uid_t audit_sig_uid;
      extern u32 audit_sig_sid;

      if (audit_pid && t->tgid == audit_pid) {
            if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1) {
                  audit_sig_pid = tsk->pid;
                  if (ctx)
                        audit_sig_uid = ctx->loginuid;
                  else
                        audit_sig_uid = tsk->uid;
                  selinux_get_task_sid(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;
            selinux_get_task_sid(t, &ctx->target_sid);
            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;
      selinux_get_task_sid(t, &axp->target_sid[axp->pid_count]);
      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;

      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",
                  audit_get_loginuid(current->audit_context),
                  current->uid, current->gid);
      selinux_get_task_sid(current, &sid);
      if (sid) {
            char *ctx = NULL;
            u32 len;

            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_format(ab, " pid=%d comm=", current->pid);
      audit_log_untrustedstring(ab, current->comm);
      audit_log_format(ab, " sig=%ld", signr);
      audit_log_end(ab);
}

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