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/* auditsc.c -- System-call auditing support

* Handles all system-call specific auditing features.

* 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

* 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 <linux/atomic.h>

#include <linux/fs.h>

#include <linux/namei.h>

#include <linux/mm.h>

#include <linux/export.h>

#include <linux/slab.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/capability.h>

#include <linux/fs_struct.h>

#include <linux/compat.h>

#include "audit.h"

/* flags stating the success for a syscall */

#define AUDITSC_INVALID 0

#define AUDITSC_SUCCESS 1

#define AUDITSC_FAILURE 2

/* 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;

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_execve {

struct audit_aux_data d;

int argc;

int envc;

struct mm_struct *mm;

};

struct audit_aux_data_pids {

struct audit_aux_data d;

pid_t target_pid[AUDIT_AUX_PIDS];

kuid_t target_auid[AUDIT_AUX_PIDS];

kuid_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_aux_data_bprm_fcaps {

struct audit_aux_data d;

struct audit_cap_data fcap;

unsigned int fcap_ver;

struct audit_cap_data old_pcap;

struct audit_cap_data new_pcap;

};

struct audit_aux_data_capset {

struct audit_aux_data d;

pid_t pid;

struct audit_cap_data cap;

};

struct audit_tree_refs {

struct audit_tree_refs *next;

struct audit_chunk *c[31];

};

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 val)

{

struct audit_names *n;

umode_t mode = (umode_t)val;

if (unlikely(!ctx))

return 0;

list_for_each_entry(n, &ctx->names_list, list) {

if ((n->ino != -1) &&

((n->mode & S_IFMT) == mode))

return 1;

}

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 void audit_set_auditable(struct audit_context *ctx)

{

if (!ctx->prio) {

ctx->prio = 1;

ctx->current_state = AUDIT_RECORD_CONTEXT;

}

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;

}

static int audit_compare_uid(kuid_t uid,

struct audit_names *name,

struct audit_field *f,

struct audit_context *ctx)

{

struct audit_names *n;

int rc;

if (name) {

rc = audit_uid_comparator(uid, f->op, name->uid);

if (rc)

return rc;

}

if (ctx) {

list_for_each_entry(n, &ctx->names_list, list) {

rc = audit_uid_comparator(uid, f->op, n->uid);

if (rc)

return rc;

}

return 0;

}

static int audit_compare_gid(kgid_t gid,

struct audit_names *name,

struct audit_field *f,

struct audit_context *ctx)

{

struct audit_names *n;

int rc;

if (name) {

rc = audit_gid_comparator(gid, f->op, name->gid);

if (rc)

return rc;

}

if (ctx) {

list_for_each_entry(n, &ctx->names_list, list) {

rc = audit_gid_comparator(gid, f->op, n->gid);

if (rc)

return rc;

}

return 0;

}

static int audit_field_compare(struct task_struct *tsk,

const struct cred *cred,

struct audit_field *f,

struct audit_context *ctx,

struct audit_names *name)

{

switch (f->val) {

/* process to file object comparisons */

case AUDIT_COMPARE_UID_TO_OBJ_UID:

return audit_compare_uid(cred->uid, name, f, ctx);

case AUDIT_COMPARE_GID_TO_OBJ_GID:

return audit_compare_gid(cred->gid, name, f, ctx);

case AUDIT_COMPARE_EUID_TO_OBJ_UID:

return audit_compare_uid(cred->euid, name, f, ctx);

case AUDIT_COMPARE_EGID_TO_OBJ_GID:

return audit_compare_gid(cred->egid, name, f, ctx);

case AUDIT_COMPARE_AUID_TO_OBJ_UID:

return audit_compare_uid(tsk->loginuid, name, f, ctx);

case AUDIT_COMPARE_SUID_TO_OBJ_UID:

return audit_compare_uid(cred->suid, name, f, ctx);

case AUDIT_COMPARE_SGID_TO_OBJ_GID:

return audit_compare_gid(cred->sgid, name, f, ctx);

case AUDIT_COMPARE_FSUID_TO_OBJ_UID:

return audit_compare_uid(cred->fsuid, name, f, ctx);

case AUDIT_COMPARE_FSGID_TO_OBJ_GID:

return audit_compare_gid(cred->fsgid, name, f, ctx);

/* uid comparisons */

case AUDIT_COMPARE_UID_TO_AUID:

return audit_uid_comparator(cred->uid, f->op, tsk->loginuid);

case AUDIT_COMPARE_UID_TO_EUID:

return audit_uid_comparator(cred->uid, f->op, cred->euid);

case AUDIT_COMPARE_UID_TO_SUID:

return audit_uid_comparator(cred->uid, f->op, cred->suid);

case AUDIT_COMPARE_UID_TO_FSUID:

return audit_uid_comparator(cred->uid, f->op, cred->fsuid);

/* auid comparisons */

case AUDIT_COMPARE_AUID_TO_EUID:

return audit_uid_comparator(tsk->loginuid, f->op, cred->euid);

case AUDIT_COMPARE_AUID_TO_SUID:

return audit_uid_comparator(tsk->loginuid, f->op, cred->suid);

case AUDIT_COMPARE_AUID_TO_FSUID:

return audit_uid_comparator(tsk->loginuid, f->op, cred->fsuid);

/* euid comparisons */

case AUDIT_COMPARE_EUID_TO_SUID:

return audit_uid_comparator(cred->euid, f->op, cred->suid);

case AUDIT_COMPARE_EUID_TO_FSUID:

return audit_uid_comparator(cred->euid, f->op, cred->fsuid);

/* suid comparisons */

case AUDIT_COMPARE_SUID_TO_FSUID:

return audit_uid_comparator(cred->suid, f->op, cred->fsuid);

/* gid comparisons */

case AUDIT_COMPARE_GID_TO_EGID:

return audit_gid_comparator(cred->gid, f->op, cred->egid);

case AUDIT_COMPARE_GID_TO_SGID:

return audit_gid_comparator(cred->gid, f->op, cred->sgid);

case AUDIT_COMPARE_GID_TO_FSGID:

return audit_gid_comparator(cred->gid, f->op, cred->fsgid);

/* egid comparisons */

case AUDIT_COMPARE_EGID_TO_SGID:

return audit_gid_comparator(cred->egid, f->op, cred->sgid);

case AUDIT_COMPARE_EGID_TO_FSGID:

return audit_gid_comparator(cred->egid, f->op, cred->fsgid);

/* sgid comparison */

case AUDIT_COMPARE_SGID_TO_FSGID:

return audit_gid_comparator(cred->sgid, f->op, cred->fsgid);

default:

WARN(1, "Missing AUDIT_COMPARE define. Report as a bug\n");

return 0;

}

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.

* If task_creation is true, this is an explicit indication that we are

* filtering a task rule at task creation time. This and tsk == current are

* the only situations where tsk->cred may be accessed without an rcu read lock.

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,

bool task_creation)

{

const struct cred *cred;

int i, need_sid = 1;

u32 sid;

cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation);

for (i = 0; i < rule->field_count; i++) {

struct audit_field *f = &rule->fields[i];

struct audit_names *n;

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_uid_comparator(cred->uid, f->op, f->uid);

break;

case AUDIT_EUID:

result = audit_uid_comparator(cred->euid, f->op, f->uid);

break;

case AUDIT_SUID:

result = audit_uid_comparator(cred->suid, f->op, f->uid);

break;

case AUDIT_FSUID:

result = audit_uid_comparator(cred->fsuid, f->op, f->uid);

break;

case AUDIT_GID:

result = audit_gid_comparator(cred->gid, f->op, f->gid);

if (f->op == Audit_equal) {

if (!result)

result = in_group_p(f->gid);

} else if (f->op == Audit_not_equal) {

if (result)

result = !in_group_p(f->gid);

}

break;

case AUDIT_EGID:

result = audit_gid_comparator(cred->egid, f->op, f->gid);

if (f->op == Audit_equal) {

if (!result)

result = in_egroup_p(f->gid);

} else if (f->op == Audit_not_equal) {

if (result)

result = !in_egroup_p(f->gid);

}

break;

case AUDIT_SGID:

result = audit_gid_comparator(cred->sgid, f->op, f->gid);

break;

case AUDIT_FSGID:

result = audit_gid_comparator(cred->fsgid, f->op, f->gid);

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) {

if (audit_comparator(MAJOR(name->dev), f->op, f->val) ||

audit_comparator(MAJOR(name->rdev), f->op, f->val))

++result;

} else if (ctx) {

list_for_each_entry(n, &ctx->names_list, list) {

if (audit_comparator(MAJOR(n->dev), f->op, f->val) ||

audit_comparator(MAJOR(n->rdev), f->op, f->val)) {

++result;

break;

}

break;

case AUDIT_DEVMINOR:

if (name) {

if (audit_comparator(MINOR(name->dev), f->op, f->val) ||

audit_comparator(MINOR(name->rdev), f->op, f->val))

++result;

} else if (ctx) {

list_for_each_entry(n, &ctx->names_list, list) {

if (audit_comparator(MINOR(n->dev), f->op, f->val) ||

audit_comparator(MINOR(n->rdev), f->op, f->val)) {

++result;

break;

}

break;

case AUDIT_INODE:

if (name)

result = (name->ino == f->val);

else if (ctx) {

list_for_each_entry(n, &ctx->names_list, list) {

if (audit_comparator(n->ino, f->op, f->val)) {

++result;

break;

}

break;

case AUDIT_OBJ_UID:

if (name) {

result = audit_uid_comparator(name->uid, f->op, f->uid);

} else if (ctx) {

list_for_each_entry(n, &ctx->names_list, list) {

if (audit_uid_comparator(n->uid, f->op, f->uid)) {

++result;

break;

}

break;

case AUDIT_OBJ_GID:

if (name) {

result = audit_gid_comparator(name->gid, f->op, f->gid);

} else if (ctx) {

list_for_each_entry(n, &ctx->names_list, list) {

if (audit_gid_comparator(n->gid, f->op, f->gid)) {

++result;

break;

}

break;

case AUDIT_WATCH:

if (name)

result = audit_watch_compare(rule->watch, name->ino, name->dev);

break;

case AUDIT_DIR:

if (ctx)

result = match_tree_refs(ctx, rule->tree);

break;

case AUDIT_LOGINUID:

result = 0;

if (ctx)

result = audit_uid_comparator(tsk->loginuid, f->op, f->uid);

break;

case AUDIT_LOGINUID_SET:

result = audit_comparator(audit_loginuid_set(tsk), 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) {

list_for_each_entry(n, &ctx->names_list, list) {

if (security_audit_rule_match(n->osid, f->type,

f->op, f->lsm_rule,

ctx)) {

++result;

break;

}

/* Find ipc objects that match */

if (!ctx || ctx->type != AUDIT_IPC)

break;

if (security_audit_rule_match(ctx->ipc.osid,

f->type, f->op,

f->lsm_rule, ctx))

++result;

}

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;

case AUDIT_FIELD_COMPARE:

result = audit_field_compare(tsk, cred, f, ctx, name);

break;

}

if (!result)

return 0;

}

if (ctx) {

if (rule->prio <= ctx->prio)

return 0;

if (rule->filterkey) {

kfree(ctx->filterkey);

ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);

}

ctx->prio = rule->prio;

}

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, char **key)

{

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, true)) {

if (state == AUDIT_RECORD_CONTEXT)

*key = kstrdup(e->rule.filterkey, GFP_ATOMIC);

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, false)) {

rcu_read_unlock();

ctx->current_state = state;

return state;

}

rcu_read_unlock();

return AUDIT_BUILD_CONTEXT;

}

* Given an audit_name check the inode hash table to see if they match.

* Called holding the rcu read lock to protect the use of audit_inode_hash

static int audit_filter_inode_name(struct task_struct *tsk,

struct audit_names *n,

struct audit_context *ctx) {

int word, bit;

int h = audit_hash_ino((u32)n->ino);

struct list_head *list = &audit_inode_hash[h];

struct audit_entry *e;

enum audit_state state;

word = AUDIT_WORD(ctx->major);

bit = AUDIT_BIT(ctx->major);

if (list_empty(list))

return 0;

list_for_each_entry_rcu(e, list, list) {

if ((e->rule.mask[word] & bit) == bit &&

audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {

ctx->current_state = state;

return 1;

}

return 0;

}

/* 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().

void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx)

{

struct audit_names *n;

if (audit_pid && tsk->tgid == audit_pid)

return;

rcu_read_lock();

list_for_each_entry(n, &ctx->names_list, list) {

if (audit_filter_inode_name(tsk, n, ctx))

break;

}

rcu_read_unlock();

}

static inline struct audit_context *audit_get_context(struct task_struct *tsk,

int return_valid,

long return_code)

{

struct audit_context *context = tsk->audit_context;

if (!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) {

audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]);

audit_filter_inodes(tsk, context);

}

tsk->audit_context = NULL;

return context;

}

static inline void audit_free_names(struct audit_context *context)

{

struct audit_names *n, *next;

#if AUDIT_DEBUG == 2

if (context->put_count + context->ino_count != context->name_count) {

int i = 0;

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);

list_for_each_entry(n, &context->names_list, list) {

printk(KERN_ERR "names[%d] = %p = %s\n", i++,

n->name, n->name->name ?: "(null)");

}

dump_stack();

return;

}

#endif

#if AUDIT_DEBUG

context->put_count = 0;

context->ino_count = 0;

#endif

list_for_each_entry_safe(n, next, &context->names_list, list) {

list_del(&n->list);

if (n->name && n->name_put)

final_putname(n->name);

if (n->should_free)

kfree(n);

}

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 struct audit_context *audit_alloc_context(enum audit_state state)

{

struct audit_context *context;

context = kzalloc(sizeof(*context), GFP_KERNEL);

if (!context)

return NULL;

context->state = state;

context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0;

INIT_LIST_HEAD(&context->killed_trees);

INIT_LIST_HEAD(&context->names_list);

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;

char *key = NULL;

if (likely(!audit_ever_enabled))

return 0; /* Return if not auditing. */

state = audit_filter_task(tsk, &key);

if (state == AUDIT_DISABLED)

return 0;

if (!(context = audit_alloc_context(state))) {

kfree(key);

audit_log_lost("out of memory in audit_alloc");

return -ENOMEM;

}

context->filterkey = key;

tsk->audit_context = context;

set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT);

return 0;

}

static inline void audit_free_context(struct audit_context *context)

{

audit_free_names(context);

unroll_tree_refs(context, NULL, 0);

free_tree_refs(context);

audit_free_aux(context);

kfree(context->filterkey);

kfree(context->sockaddr);

kfree(context);

}

static int audit_log_pid_context(struct audit_context *context, pid_t pid,

kuid_t auid, kuid_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,

from_kuid(&init_user_ns, auid),

from_kuid(&init_user_ns, uid), sessionid);

if (sid) {

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);

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linux/kernel/auditsc.c at master · fabgithub/linux · GitHub

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