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ce29b682e2
kernel_optimize_test/kernel/auditsc.c
Steve Grubb ce29b682e2 [PATCH] More user space subject labels 
Hi,

The patch below builds upon the patch sent earlier and adds subject label to
all audit events generated via the netlink interface. It also cleans up a few
other minor things.

Signed-off-by: Steve Grubb <sgrubb@redhat.com>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2006-05-01 06:10:01 -04:00

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/* 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 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.
*
* 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 <asm/types.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/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 "audit.h"
extern struct list_head audit_filter_list[];
/* No syscall auditing will take place unless audit_enabled != 0. */
extern int audit_enabled;
/* AUDIT_NAMES is the number of slots we reserve in the audit_context
* for saving names from getname(). */
#define AUDIT_NAMES 20
/* AUDIT_NAMES_RESERVED is the number of slots we reserve in the
* audit_context from being used for nameless inodes from
* path_lookup. */
#define AUDIT_NAMES_RESERVED 7
/* 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;
unsigned long ino;
unsigned long pino;
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
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_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_path {
struct audit_aux_data d;
struct dentry *dentry;
struct vfsmount *mnt;
};
/* The per-task audit context. */
struct audit_context {
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];
struct dentry * pwd;
struct vfsmount * pwdmnt;
struct audit_context *previous; /* For nested syscalls */
struct audit_aux_data *aux;
/* Save things to print about task_struct */
pid_t pid;
uid_t uid, euid, suid, fsuid;
gid_t gid, egid, sgid, fsgid;
unsigned long personality;
int arch;
#if AUDIT_DEBUG
int put_count;
int ino_count;
#endif
};
/* 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,
enum audit_state *state)
{
int i, j;
u32 sid;
selinux_task_ctxid(tsk, &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_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 (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 (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 (ctx) {
for (j = 0; j < ctx->name_count; j++) {
if (audit_comparator(ctx->names[j].ino, f->op, f->val) ||
audit_comparator(ctx->names[j].pino, f->op, f->val)) {
++result;
break;
}
}
}
break;
case AUDIT_LOGINUID:
result = 0;
if (ctx)
result = audit_comparator(ctx->loginuid, f->op, f->val);
break;
case AUDIT_SE_USER:
case AUDIT_SE_ROLE:
case AUDIT_SE_TYPE:
case AUDIT_SE_SEN:
case AUDIT_SE_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)
result = selinux_audit_rule_match(sid, f->type,
f->op,
f->se_rule,
ctx);
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;
}
if (!result)
return 0;
}
switch (rule->action) {
case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; 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, &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, &state)) {
rcu_read_unlock();
return state;
}
}
}
rcu_read_unlock();
return AUDIT_BUILD_CONTEXT;
}
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->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;
}
context->pid = tsk->pid;
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;
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)
__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)) {
if (aux->type == AUDIT_AVC_PATH) {
struct audit_aux_data_path *axi = (void *)aux;
dput(axi->dentry);
mntput(axi->mnt);
}
context->aux = 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);
audit_free_aux(context);
kfree(context);
context = previous;
} while (context);
if (count >= 10)
printk(KERN_ERR "audit: freed %d contexts\n", count);
}
static void audit_log_task_context(struct audit_buffer *ab)
{
char *ctx = NULL;
ssize_t len = 0;
len = security_getprocattr(current, "current", NULL, 0);
if (len < 0) {
if (len != -EINVAL)
goto error_path;
return;
}
ctx = kmalloc(len, GFP_KERNEL);
if (!ctx)
goto error_path;
len = security_getprocattr(current, "current", ctx, len);
if (len < 0 )
goto error_path;
audit_log_format(ab, " subj=%s", ctx);
return;
error_path:
if (ctx)
kfree(ctx);
audit_panic("error in audit_log_task_context");
return;
}
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_dentry,
vma->vm_file->f_vfsmnt);
break;
}
vma = vma->vm_next;
}
up_read(&mm->mmap_sem);
}
audit_log_task_context(ab);
}
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 */
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);
if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
tty = tsk->signal->tty->name;
else
tty = "(none)";
audit_log_format(ab,
" a0=%lx a1=%lx a2=%lx a3=%lx items=%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->pid,
context->loginuid,
context->uid,
context->gid,
context->euid, context->suid, context->fsuid,
context->egid, context->sgid, context->fsgid, tty);
audit_log_task_info(ab, tsk);
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_IPC: {
struct audit_aux_data_ipcctl *axi = (void *)aux;
audit_log_format(ab,
" qbytes=%lx iuid=%u igid=%u mode=%x",
axi->qbytes, axi->uid, axi->gid, axi->mode);
if (axi->osid != 0) {
char *ctx = NULL;
u32 len;
if (selinux_ctxid_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_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_AVC_PATH: {
struct audit_aux_data_path *axi = (void *)aux;
audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);
break; }
}
audit_log_end(ab);
}
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++) {
unsigned long ino = context->names[i].ino;
unsigned long pino = context->names[i].pino;
ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
if (!ab)
continue; /* audit_panic has been called */
audit_log_format(ab, "item=%d", i);
audit_log_format(ab, " name=");
if (context->names[i].name)
audit_log_untrustedstring(ab, context->names[i].name);
else
audit_log_format(ab, "(null)");
if (pino != (unsigned long)-1)
audit_log_format(ab, " parent=%lu", pino);
if (ino != (unsigned long)-1)
audit_log_format(ab, " inode=%lu", ino);
if ((pino != (unsigned long)-1) || (ino != (unsigned long)-1))
audit_log_format(ab, " dev=%02x:%02x mode=%#o"
" ouid=%u ogid=%u rdev=%02x:%02x",
MAJOR(context->names[i].dev),
MINOR(context->names[i].dev),
context->names[i].mode,
context->names[i].uid,
context->names[i].gid,
MAJOR(context->names[i].rdev),
MINOR(context->names[i].rdev));
if (context->names[i].osid != 0) {
char *ctx = NULL;
u32 len;
if (selinux_ctxid_to_string(
context->names[i].osid, &ctx, &len)) {
audit_log_format(ab, " osid=%u",
context->names[i].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;
if (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);
}
/**
* 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);
audit_free_aux(context);
tsk->audit_context = context;
}
}
/**
* 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 (!context || 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].ino = (unsigned long)-1;
++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 void audit_inode_context(int idx, const struct inode *inode)
{
struct audit_context *context = current->audit_context;
selinux_get_inode_sid(inode, &context->names[idx].osid);
}
/**
* audit_inode - store the inode and device from a lookup
* @name: name being audited
* @inode: inode being audited
* @flags: lookup flags (as used in path_lookup())
*
* Called from fs/namei.c:path_lookup().
*/
void __audit_inode(const char *name, const struct inode *inode, unsigned flags)
{
int idx;
struct audit_context *context = current->audit_context;
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 (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED)
return;
idx = context->name_count++;
context->names[idx].name = NULL;
#if AUDIT_DEBUG
++context->ino_count;
#endif
}
context->names[idx].dev = inode->i_sb->s_dev;
context->names[idx].mode = inode->i_mode;
context->names[idx].uid = inode->i_uid;
context->names[idx].gid = inode->i_gid;
context->names[idx].rdev = inode->i_rdev;
audit_inode_context(idx, inode);
if ((flags & LOOKUP_PARENT) && (strcmp(name, "/") != 0) &&
(strcmp(name, ".") != 0)) {
context->names[idx].ino = (unsigned long)-1;
context->names[idx].pino = inode->i_ino;
} else {
context->names[idx].ino = inode->i_ino;
context->names[idx].pino = (unsigned long)-1;
}
}
/**
* audit_inode_child - collect inode info for created/removed objects
* @dname: inode's dentry name
* @inode: inode being audited
* @pino: inode number 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 inode *inode,
unsigned long pino)
{
int idx;
struct audit_context *context = current->audit_context;
if (!context->in_syscall)
return;
/* determine matching parent */
if (dname)
for (idx = 0; idx < context->name_count; idx++)
if (context->names[idx].pino == pino) {
const char *n;
const char *name = context->names[idx].name;
int dlen = strlen(dname);
int nlen = name ? strlen(name) : 0;
if (nlen < dlen)
continue;
/* disregard trailing slashes */
n = name + nlen - 1;
while ((*n == '/') && (n > name))
n--;
/* find last path component */
n = n - dlen + 1;
if (n < name)
continue;
else if (n > name) {
if (*--n != '/')
continue;
else
n++;
}
if (strncmp(n, dname, dlen) == 0)
goto update_context;
}
/* catch-all in case match not found */
idx = context->name_count++;
context->names[idx].name = NULL;
context->names[idx].pino = pino;
#if AUDIT_DEBUG
context->ino_count++;
#endif
update_context:
if (inode) {
context->names[idx].ino = inode->i_ino;
context->names[idx].dev = inode->i_sb->s_dev;
context->names[idx].mode = inode->i_mode;
context->names[idx].uid = inode->i_uid;
context->names[idx].gid = inode->i_gid;
context->names[idx].rdev = inode->i_rdev;
audit_inode_context(idx, inode);
}
}
/**
* 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)
{
if (task->audit_context) {
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,
task->audit_context->loginuid, loginuid);
audit_log_end(ab);
}
task->audit_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;
}
/**
* audit_ipc_perms - record audit data for ipc
* @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_perms(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode, struct kern_ipc_perm *ipcp)
{
struct audit_aux_data_ipcctl *ax;
struct audit_context *context = current->audit_context;
if (likely(!context))
return 0;
ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
if (!ax)
return -ENOMEM;
ax->qbytes = qbytes;
ax->uid = uid;
ax->gid = gid;
ax->mode = 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_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))
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_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))
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;
}
/**
* audit_avc_path - record the granting or denial of permissions
* @dentry: dentry to record
* @mnt: mnt to record
*
* Returns 0 for success or NULL context or < 0 on error.
*
* Called from security/selinux/avc.c::avc_audit()
*/
int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
{
struct audit_aux_data_path *ax;
struct audit_context *context = current->audit_context;
if (likely(!context))
return 0;
ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
if (!ax)
return -ENOMEM;
ax->dentry = dget(dentry);
ax->mnt = mntget(mnt);
ax->d.type = AUDIT_AVC_PATH;
ax->d.next = context->aux;
context->aux = (void *)ax;
return 0;
}
/**
* 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.
*/
void audit_signal_info(int sig, struct task_struct *t)
{
extern pid_t audit_sig_pid;
extern uid_t audit_sig_uid;
if (unlikely(audit_pid && t->tgid == audit_pid)) {
if (sig == SIGTERM || sig == SIGHUP) {
struct audit_context *ctx = current->audit_context;
audit_sig_pid = current->pid;
if (ctx)
audit_sig_uid = ctx->loginuid;
else
audit_sig_uid = current->uid;
}
}
}
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