~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/security/tomoyo/audit.c

Version: ~ [ linux-5.10-rc6 ] ~ [ linux-5.9.12 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.81 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.161 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.210 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.247 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.247 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * security/tomoyo/audit.c
  4  *
  5  * Copyright (C) 2005-2011  NTT DATA CORPORATION
  6  */
  7 
  8 #include "common.h"
  9 #include <linux/slab.h>
 10 
 11 /**
 12  * tomoyo_print_bprm - Print "struct linux_binprm" for auditing.
 13  *
 14  * @bprm: Pointer to "struct linux_binprm".
 15  * @dump: Pointer to "struct tomoyo_page_dump".
 16  *
 17  * Returns the contents of @bprm on success, NULL otherwise.
 18  *
 19  * This function uses kzalloc(), so caller must kfree() if this function
 20  * didn't return NULL.
 21  */
 22 static char *tomoyo_print_bprm(struct linux_binprm *bprm,
 23                                struct tomoyo_page_dump *dump)
 24 {
 25         static const int tomoyo_buffer_len = 4096 * 2;
 26         char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS);
 27         char *cp;
 28         char *last_start;
 29         int len;
 30         unsigned long pos = bprm->p;
 31         int offset = pos % PAGE_SIZE;
 32         int argv_count = bprm->argc;
 33         int envp_count = bprm->envc;
 34         bool truncated = false;
 35         if (!buffer)
 36                 return NULL;
 37         len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ ");
 38         cp = buffer + len;
 39         if (!argv_count) {
 40                 memmove(cp, "} envp[]={ ", 11);
 41                 cp += 11;
 42         }
 43         last_start = cp;
 44         while (argv_count || envp_count) {
 45                 if (!tomoyo_dump_page(bprm, pos, dump))
 46                         goto out;
 47                 pos += PAGE_SIZE - offset;
 48                 /* Read. */
 49                 while (offset < PAGE_SIZE) {
 50                         const char *kaddr = dump->data;
 51                         const unsigned char c = kaddr[offset++];
 52                         if (cp == last_start)
 53                                 *cp++ = '"';
 54                         if (cp >= buffer + tomoyo_buffer_len - 32) {
 55                                 /* Reserve some room for "..." string. */
 56                                 truncated = true;
 57                         } else if (c == '\\') {
 58                                 *cp++ = '\\';
 59                                 *cp++ = '\\';
 60                         } else if (c > ' ' && c < 127) {
 61                                 *cp++ = c;
 62                         } else if (!c) {
 63                                 *cp++ = '"';
 64                                 *cp++ = ' ';
 65                                 last_start = cp;
 66                         } else {
 67                                 *cp++ = '\\';
 68                                 *cp++ = (c >> 6) + '';
 69                                 *cp++ = ((c >> 3) & 7) + '';
 70                                 *cp++ = (c & 7) + '';
 71                         }
 72                         if (c)
 73                                 continue;
 74                         if (argv_count) {
 75                                 if (--argv_count == 0) {
 76                                         if (truncated) {
 77                                                 cp = last_start;
 78                                                 memmove(cp, "... ", 4);
 79                                                 cp += 4;
 80                                         }
 81                                         memmove(cp, "} envp[]={ ", 11);
 82                                         cp += 11;
 83                                         last_start = cp;
 84                                         truncated = false;
 85                                 }
 86                         } else if (envp_count) {
 87                                 if (--envp_count == 0) {
 88                                         if (truncated) {
 89                                                 cp = last_start;
 90                                                 memmove(cp, "... ", 4);
 91                                                 cp += 4;
 92                                         }
 93                                 }
 94                         }
 95                         if (!argv_count && !envp_count)
 96                                 break;
 97                 }
 98                 offset = 0;
 99         }
100         *cp++ = '}';
101         *cp = '\0';
102         return buffer;
103 out:
104         snprintf(buffer, tomoyo_buffer_len - 1,
105                  "argv[]={ ... } envp[]= { ... }");
106         return buffer;
107 }
108 
109 /**
110  * tomoyo_filetype - Get string representation of file type.
111  *
112  * @mode: Mode value for stat().
113  *
114  * Returns file type string.
115  */
116 static inline const char *tomoyo_filetype(const umode_t mode)
117 {
118         switch (mode & S_IFMT) {
119         case S_IFREG:
120         case 0:
121                 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE];
122         case S_IFDIR:
123                 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY];
124         case S_IFLNK:
125                 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK];
126         case S_IFIFO:
127                 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO];
128         case S_IFSOCK:
129                 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET];
130         case S_IFBLK:
131                 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV];
132         case S_IFCHR:
133                 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV];
134         }
135         return "unknown"; /* This should not happen. */
136 }
137 
138 /**
139  * tomoyo_print_header - Get header line of audit log.
140  *
141  * @r: Pointer to "struct tomoyo_request_info".
142  *
143  * Returns string representation.
144  *
145  * This function uses kmalloc(), so caller must kfree() if this function
146  * didn't return NULL.
147  */
148 static char *tomoyo_print_header(struct tomoyo_request_info *r)
149 {
150         struct tomoyo_time stamp;
151         const pid_t gpid = task_pid_nr(current);
152         struct tomoyo_obj_info *obj = r->obj;
153         static const int tomoyo_buffer_len = 4096;
154         char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
155         int pos;
156         u8 i;
157         if (!buffer)
158                 return NULL;
159 
160         tomoyo_convert_time(ktime_get_real_seconds(), &stamp);
161 
162         pos = snprintf(buffer, tomoyo_buffer_len - 1,
163                        "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
164                        "granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
165                        "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
166                        "fsuid=%u fsgid=%u }", stamp.year, stamp.month,
167                        stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile,
168                        tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid,
169                        tomoyo_sys_getpid(), tomoyo_sys_getppid(),
170                        from_kuid(&init_user_ns, current_uid()),
171                        from_kgid(&init_user_ns, current_gid()),
172                        from_kuid(&init_user_ns, current_euid()),
173                        from_kgid(&init_user_ns, current_egid()),
174                        from_kuid(&init_user_ns, current_suid()),
175                        from_kgid(&init_user_ns, current_sgid()),
176                        from_kuid(&init_user_ns, current_fsuid()),
177                        from_kgid(&init_user_ns, current_fsgid()));
178         if (!obj)
179                 goto no_obj_info;
180         if (!obj->validate_done) {
181                 tomoyo_get_attributes(obj);
182                 obj->validate_done = true;
183         }
184         for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
185                 struct tomoyo_mini_stat *stat;
186                 unsigned int dev;
187                 umode_t mode;
188                 if (!obj->stat_valid[i])
189                         continue;
190                 stat = &obj->stat[i];
191                 dev = stat->dev;
192                 mode = stat->mode;
193                 if (i & 1) {
194                         pos += snprintf(buffer + pos,
195                                         tomoyo_buffer_len - 1 - pos,
196                                         " path%u.parent={ uid=%u gid=%u "
197                                         "ino=%lu perm=0%o }", (i >> 1) + 1,
198                                         from_kuid(&init_user_ns, stat->uid),
199                                         from_kgid(&init_user_ns, stat->gid),
200                                         (unsigned long)stat->ino,
201                                         stat->mode & S_IALLUGO);
202                         continue;
203                 }
204                 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
205                                 " path%u={ uid=%u gid=%u ino=%lu major=%u"
206                                 " minor=%u perm=0%o type=%s", (i >> 1) + 1,
207                                 from_kuid(&init_user_ns, stat->uid),
208                                 from_kgid(&init_user_ns, stat->gid),
209                                 (unsigned long)stat->ino,
210                                 MAJOR(dev), MINOR(dev),
211                                 mode & S_IALLUGO, tomoyo_filetype(mode));
212                 if (S_ISCHR(mode) || S_ISBLK(mode)) {
213                         dev = stat->rdev;
214                         pos += snprintf(buffer + pos,
215                                         tomoyo_buffer_len - 1 - pos,
216                                         " dev_major=%u dev_minor=%u",
217                                         MAJOR(dev), MINOR(dev));
218                 }
219                 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
220                                 " }");
221         }
222 no_obj_info:
223         if (pos < tomoyo_buffer_len - 1)
224                 return buffer;
225         kfree(buffer);
226         return NULL;
227 }
228 
229 /**
230  * tomoyo_init_log - Allocate buffer for audit logs.
231  *
232  * @r:    Pointer to "struct tomoyo_request_info".
233  * @len:  Buffer size needed for @fmt and @args.
234  * @fmt:  The printf()'s format string.
235  * @args: va_list structure for @fmt.
236  *
237  * Returns pointer to allocated memory.
238  *
239  * This function uses kzalloc(), so caller must kfree() if this function
240  * didn't return NULL.
241  */
242 char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
243                       va_list args)
244 {
245         char *buf = NULL;
246         char *bprm_info = NULL;
247         const char *header = NULL;
248         char *realpath = NULL;
249         const char *symlink = NULL;
250         int pos;
251         const char *domainname = r->domain->domainname->name;
252         header = tomoyo_print_header(r);
253         if (!header)
254                 return NULL;
255         /* +10 is for '\n' etc. and '\0'. */
256         len += strlen(domainname) + strlen(header) + 10;
257         if (r->ee) {
258                 struct file *file = r->ee->bprm->file;
259                 realpath = tomoyo_realpath_from_path(&file->f_path);
260                 bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
261                 if (!realpath || !bprm_info)
262                         goto out;
263                 /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
264                 len += strlen(realpath) + 80 + strlen(bprm_info);
265         } else if (r->obj && r->obj->symlink_target) {
266                 symlink = r->obj->symlink_target->name;
267                 /* +18 is for " symlink.target=\"%s\"" */
268                 len += 18 + strlen(symlink);
269         }
270         len = tomoyo_round2(len);
271         buf = kzalloc(len, GFP_NOFS);
272         if (!buf)
273                 goto out;
274         len--;
275         pos = snprintf(buf, len, "%s", header);
276         if (realpath) {
277                 struct linux_binprm *bprm = r->ee->bprm;
278                 pos += snprintf(buf + pos, len - pos,
279                                 " exec={ realpath=\"%s\" argc=%d envc=%d %s }",
280                                 realpath, bprm->argc, bprm->envc, bprm_info);
281         } else if (symlink)
282                 pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
283                                 symlink);
284         pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
285         vsnprintf(buf + pos, len - pos, fmt, args);
286 out:
287         kfree(realpath);
288         kfree(bprm_info);
289         kfree(header);
290         return buf;
291 }
292 
293 /* Wait queue for /sys/kernel/security/tomoyo/audit. */
294 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
295 
296 /* Structure for audit log. */
297 struct tomoyo_log {
298         struct list_head list;
299         char *log;
300         int size;
301 };
302 
303 /* The list for "struct tomoyo_log". */
304 static LIST_HEAD(tomoyo_log);
305 
306 /* Lock for "struct list_head tomoyo_log". */
307 static DEFINE_SPINLOCK(tomoyo_log_lock);
308 
309 /* Length of "stuct list_head tomoyo_log". */
310 static unsigned int tomoyo_log_count;
311 
312 /**
313  * tomoyo_get_audit - Get audit mode.
314  *
315  * @ns:          Pointer to "struct tomoyo_policy_namespace".
316  * @profile:     Profile number.
317  * @index:       Index number of functionality.
318  * @is_granted:  True if granted log, false otherwise.
319  *
320  * Returns true if this request should be audited, false otherwise.
321  */
322 static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns,
323                              const u8 profile, const u8 index,
324                              const struct tomoyo_acl_info *matched_acl,
325                              const bool is_granted)
326 {
327         u8 mode;
328         const u8 category = tomoyo_index2category[index] +
329                 TOMOYO_MAX_MAC_INDEX;
330         struct tomoyo_profile *p;
331         if (!tomoyo_policy_loaded)
332                 return false;
333         p = tomoyo_profile(ns, profile);
334         if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
335                 return false;
336         if (is_granted && matched_acl && matched_acl->cond &&
337             matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO)
338                 return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES;
339         mode = p->config[index];
340         if (mode == TOMOYO_CONFIG_USE_DEFAULT)
341                 mode = p->config[category];
342         if (mode == TOMOYO_CONFIG_USE_DEFAULT)
343                 mode = p->default_config;
344         if (is_granted)
345                 return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
346         return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
347 }
348 
349 /**
350  * tomoyo_write_log2 - Write an audit log.
351  *
352  * @r:    Pointer to "struct tomoyo_request_info".
353  * @len:  Buffer size needed for @fmt and @args.
354  * @fmt:  The printf()'s format string.
355  * @args: va_list structure for @fmt.
356  *
357  * Returns nothing.
358  */
359 void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
360                        va_list args)
361 {
362         char *buf;
363         struct tomoyo_log *entry;
364         bool quota_exceeded = false;
365         if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type,
366                               r->matched_acl, r->granted))
367                 goto out;
368         buf = tomoyo_init_log(r, len, fmt, args);
369         if (!buf)
370                 goto out;
371         entry = kzalloc(sizeof(*entry), GFP_NOFS);
372         if (!entry) {
373                 kfree(buf);
374                 goto out;
375         }
376         entry->log = buf;
377         len = tomoyo_round2(strlen(buf) + 1);
378         /*
379          * The entry->size is used for memory quota checks.
380          * Don't go beyond strlen(entry->log).
381          */
382         entry->size = len + tomoyo_round2(sizeof(*entry));
383         spin_lock(&tomoyo_log_lock);
384         if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
385             tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
386             tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
387                 quota_exceeded = true;
388         } else {
389                 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
390                 list_add_tail(&entry->list, &tomoyo_log);
391                 tomoyo_log_count++;
392         }
393         spin_unlock(&tomoyo_log_lock);
394         if (quota_exceeded) {
395                 kfree(buf);
396                 kfree(entry);
397                 goto out;
398         }
399         wake_up(&tomoyo_log_wait);
400 out:
401         return;
402 }
403 
404 /**
405  * tomoyo_write_log - Write an audit log.
406  *
407  * @r:   Pointer to "struct tomoyo_request_info".
408  * @fmt: The printf()'s format string, followed by parameters.
409  *
410  * Returns nothing.
411  */
412 void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
413 {
414         va_list args;
415         int len;
416         va_start(args, fmt);
417         len = vsnprintf((char *) &len, 1, fmt, args) + 1;
418         va_end(args);
419         va_start(args, fmt);
420         tomoyo_write_log2(r, len, fmt, args);
421         va_end(args);
422 }
423 
424 /**
425  * tomoyo_read_log - Read an audit log.
426  *
427  * @head: Pointer to "struct tomoyo_io_buffer".
428  *
429  * Returns nothing.
430  */
431 void tomoyo_read_log(struct tomoyo_io_buffer *head)
432 {
433         struct tomoyo_log *ptr = NULL;
434         if (head->r.w_pos)
435                 return;
436         kfree(head->read_buf);
437         head->read_buf = NULL;
438         spin_lock(&tomoyo_log_lock);
439         if (!list_empty(&tomoyo_log)) {
440                 ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
441                 list_del(&ptr->list);
442                 tomoyo_log_count--;
443                 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
444         }
445         spin_unlock(&tomoyo_log_lock);
446         if (ptr) {
447                 head->read_buf = ptr->log;
448                 head->r.w[head->r.w_pos++] = head->read_buf;
449                 kfree(ptr);
450         }
451 }
452 
453 /**
454  * tomoyo_poll_log - Wait for an audit log.
455  *
456  * @file: Pointer to "struct file".
457  * @wait: Pointer to "poll_table". Maybe NULL.
458  *
459  * Returns EPOLLIN | EPOLLRDNORM when ready to read an audit log.
460  */
461 __poll_t tomoyo_poll_log(struct file *file, poll_table *wait)
462 {
463         if (tomoyo_log_count)
464                 return EPOLLIN | EPOLLRDNORM;
465         poll_wait(file, &tomoyo_log_wait, wait);
466         if (tomoyo_log_count)
467                 return EPOLLIN | EPOLLRDNORM;
468         return 0;
469 }
470 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp