Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
| 3 | * Implementation of the kernel access vector cache (AVC). |
| 4 | * |
Stephen Smalley | 7efbb60 | 2017-08-17 13:32:36 -0400 | [diff] [blame] | 5 | * Authors: Stephen Smalley, <sds@tycho.nsa.gov> |
Eric Paris | 95fff33 | 2008-04-17 14:42:10 -0400 | [diff] [blame] | 6 | * James Morris <jmorris@redhat.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | * |
| 8 | * Update: KaiGai, Kohei <kaigai@ak.jp.nec.com> |
Eric Paris | 95fff33 | 2008-04-17 14:42:10 -0400 | [diff] [blame] | 9 | * Replaced the avc_lock spinlock by RCU. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | * |
| 11 | * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | */ |
| 13 | #include <linux/types.h> |
| 14 | #include <linux/stddef.h> |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/slab.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/dcache.h> |
| 19 | #include <linux/init.h> |
| 20 | #include <linux/skbuff.h> |
| 21 | #include <linux/percpu.h> |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 22 | #include <linux/list.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <net/sock.h> |
| 24 | #include <linux/un.h> |
| 25 | #include <net/af_unix.h> |
| 26 | #include <linux/ip.h> |
| 27 | #include <linux/audit.h> |
| 28 | #include <linux/ipv6.h> |
| 29 | #include <net/ipv6.h> |
| 30 | #include "avc.h" |
| 31 | #include "avc_ss.h" |
Stephen Smalley | c6d3aaa | 2009-09-30 13:37:50 -0400 | [diff] [blame] | 32 | #include "classmap.h" |
Chad Sellers | 5c45899 | 2006-11-06 12:38:16 -0500 | [diff] [blame] | 33 | |
ThiƩbaud Weksteen | dd81662 | 2020-08-21 16:08:21 +0200 | [diff] [blame] | 34 | #define CREATE_TRACE_POINTS |
| 35 | #include <trace/events/avc.h> |
| 36 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #define AVC_CACHE_SLOTS 512 |
| 38 | #define AVC_DEF_CACHE_THRESHOLD 512 |
| 39 | #define AVC_CACHE_RECLAIM 16 |
| 40 | |
| 41 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS |
Linus Torvalds | 044aea9 | 2011-05-19 18:59:47 -0700 | [diff] [blame] | 42 | #define avc_cache_stats_incr(field) this_cpu_inc(avc_cache_stats.field) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | #else |
| 44 | #define avc_cache_stats_incr(field) do {} while (0) |
| 45 | #endif |
| 46 | |
| 47 | struct avc_entry { |
| 48 | u32 ssid; |
| 49 | u32 tsid; |
| 50 | u16 tclass; |
| 51 | struct av_decision avd; |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 52 | struct avc_xperms_node *xp_node; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | }; |
| 54 | |
| 55 | struct avc_node { |
| 56 | struct avc_entry ae; |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 57 | struct hlist_node list; /* anchored in avc_cache->slots[i] */ |
Eric Paris | 95fff33 | 2008-04-17 14:42:10 -0400 | [diff] [blame] | 58 | struct rcu_head rhead; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | }; |
| 60 | |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 61 | struct avc_xperms_decision_node { |
| 62 | struct extended_perms_decision xpd; |
| 63 | struct list_head xpd_list; /* list of extended_perms_decision */ |
| 64 | }; |
| 65 | |
| 66 | struct avc_xperms_node { |
| 67 | struct extended_perms xp; |
| 68 | struct list_head xpd_head; /* list head of extended_perms_decision */ |
| 69 | }; |
| 70 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | struct avc_cache { |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 72 | struct hlist_head slots[AVC_CACHE_SLOTS]; /* head for avc_node->list */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | spinlock_t slots_lock[AVC_CACHE_SLOTS]; /* lock for writes */ |
| 74 | atomic_t lru_hint; /* LRU hint for reclaim scan */ |
| 75 | atomic_t active_nodes; |
| 76 | u32 latest_notif; /* latest revocation notification */ |
| 77 | }; |
| 78 | |
| 79 | struct avc_callback_node { |
Wanlong Gao | 562c99f | 2012-03-07 22:17:14 +0800 | [diff] [blame] | 80 | int (*callback) (u32 event); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | u32 events; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | struct avc_callback_node *next; |
| 83 | }; |
| 84 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS |
| 86 | DEFINE_PER_CPU(struct avc_cache_stats, avc_cache_stats) = { 0 }; |
| 87 | #endif |
| 88 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 89 | struct selinux_avc { |
| 90 | unsigned int avc_cache_threshold; |
| 91 | struct avc_cache avc_cache; |
| 92 | }; |
| 93 | |
| 94 | static struct selinux_avc selinux_avc; |
| 95 | |
| 96 | void selinux_avc_init(struct selinux_avc **avc) |
| 97 | { |
| 98 | int i; |
| 99 | |
| 100 | selinux_avc.avc_cache_threshold = AVC_DEF_CACHE_THRESHOLD; |
| 101 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { |
| 102 | INIT_HLIST_HEAD(&selinux_avc.avc_cache.slots[i]); |
| 103 | spin_lock_init(&selinux_avc.avc_cache.slots_lock[i]); |
| 104 | } |
| 105 | atomic_set(&selinux_avc.avc_cache.active_nodes, 0); |
| 106 | atomic_set(&selinux_avc.avc_cache.lru_hint, 0); |
| 107 | *avc = &selinux_avc; |
| 108 | } |
| 109 | |
| 110 | unsigned int avc_get_cache_threshold(struct selinux_avc *avc) |
| 111 | { |
| 112 | return avc->avc_cache_threshold; |
| 113 | } |
| 114 | |
| 115 | void avc_set_cache_threshold(struct selinux_avc *avc, |
| 116 | unsigned int cache_threshold) |
| 117 | { |
| 118 | avc->avc_cache_threshold = cache_threshold; |
| 119 | } |
| 120 | |
Ondrej Mosnacek | cd2bb4c | 2021-01-06 14:26:21 +0100 | [diff] [blame] | 121 | static struct avc_callback_node *avc_callbacks __ro_after_init; |
| 122 | static struct kmem_cache *avc_node_cachep __ro_after_init; |
| 123 | static struct kmem_cache *avc_xperms_data_cachep __ro_after_init; |
| 124 | static struct kmem_cache *avc_xperms_decision_cachep __ro_after_init; |
| 125 | static struct kmem_cache *avc_xperms_cachep __ro_after_init; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 126 | |
| 127 | static inline int avc_hash(u32 ssid, u32 tsid, u16 tclass) |
| 128 | { |
| 129 | return (ssid ^ (tsid<<2) ^ (tclass<<4)) & (AVC_CACHE_SLOTS - 1); |
| 130 | } |
| 131 | |
| 132 | /** |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | * avc_init - Initialize the AVC. |
| 134 | * |
| 135 | * Initialize the access vector cache. |
| 136 | */ |
| 137 | void __init avc_init(void) |
| 138 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 139 | avc_node_cachep = kmem_cache_create("avc_node", sizeof(struct avc_node), |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 140 | 0, SLAB_PANIC, NULL); |
| 141 | avc_xperms_cachep = kmem_cache_create("avc_xperms_node", |
| 142 | sizeof(struct avc_xperms_node), |
| 143 | 0, SLAB_PANIC, NULL); |
| 144 | avc_xperms_decision_cachep = kmem_cache_create( |
| 145 | "avc_xperms_decision_node", |
| 146 | sizeof(struct avc_xperms_decision_node), |
| 147 | 0, SLAB_PANIC, NULL); |
| 148 | avc_xperms_data_cachep = kmem_cache_create("avc_xperms_data", |
| 149 | sizeof(struct extended_perms_data), |
| 150 | 0, SLAB_PANIC, NULL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 151 | } |
| 152 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 153 | int avc_get_hash_stats(struct selinux_avc *avc, char *page) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | { |
| 155 | int i, chain_len, max_chain_len, slots_used; |
| 156 | struct avc_node *node; |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 157 | struct hlist_head *head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | |
| 159 | rcu_read_lock(); |
| 160 | |
| 161 | slots_used = 0; |
| 162 | max_chain_len = 0; |
| 163 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 164 | head = &avc->avc_cache.slots[i]; |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 165 | if (!hlist_empty(head)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | slots_used++; |
| 167 | chain_len = 0; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 168 | hlist_for_each_entry_rcu(node, head, list) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | chain_len++; |
| 170 | if (chain_len > max_chain_len) |
| 171 | max_chain_len = chain_len; |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | rcu_read_unlock(); |
| 176 | |
| 177 | return scnprintf(page, PAGE_SIZE, "entries: %d\nbuckets used: %d/%d\n" |
| 178 | "longest chain: %d\n", |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 179 | atomic_read(&avc->avc_cache.active_nodes), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | slots_used, AVC_CACHE_SLOTS, max_chain_len); |
| 181 | } |
| 182 | |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 183 | /* |
| 184 | * using a linked list for extended_perms_decision lookup because the list is |
| 185 | * always small. i.e. less than 5, typically 1 |
| 186 | */ |
| 187 | static struct extended_perms_decision *avc_xperms_decision_lookup(u8 driver, |
| 188 | struct avc_xperms_node *xp_node) |
| 189 | { |
| 190 | struct avc_xperms_decision_node *xpd_node; |
| 191 | |
| 192 | list_for_each_entry(xpd_node, &xp_node->xpd_head, xpd_list) { |
| 193 | if (xpd_node->xpd.driver == driver) |
| 194 | return &xpd_node->xpd; |
| 195 | } |
| 196 | return NULL; |
| 197 | } |
| 198 | |
| 199 | static inline unsigned int |
| 200 | avc_xperms_has_perm(struct extended_perms_decision *xpd, |
| 201 | u8 perm, u8 which) |
| 202 | { |
| 203 | unsigned int rc = 0; |
| 204 | |
| 205 | if ((which == XPERMS_ALLOWED) && |
| 206 | (xpd->used & XPERMS_ALLOWED)) |
| 207 | rc = security_xperm_test(xpd->allowed->p, perm); |
| 208 | else if ((which == XPERMS_AUDITALLOW) && |
| 209 | (xpd->used & XPERMS_AUDITALLOW)) |
| 210 | rc = security_xperm_test(xpd->auditallow->p, perm); |
| 211 | else if ((which == XPERMS_DONTAUDIT) && |
| 212 | (xpd->used & XPERMS_DONTAUDIT)) |
| 213 | rc = security_xperm_test(xpd->dontaudit->p, perm); |
| 214 | return rc; |
| 215 | } |
| 216 | |
| 217 | static void avc_xperms_allow_perm(struct avc_xperms_node *xp_node, |
| 218 | u8 driver, u8 perm) |
| 219 | { |
| 220 | struct extended_perms_decision *xpd; |
| 221 | security_xperm_set(xp_node->xp.drivers.p, driver); |
| 222 | xpd = avc_xperms_decision_lookup(driver, xp_node); |
| 223 | if (xpd && xpd->allowed) |
| 224 | security_xperm_set(xpd->allowed->p, perm); |
| 225 | } |
| 226 | |
| 227 | static void avc_xperms_decision_free(struct avc_xperms_decision_node *xpd_node) |
| 228 | { |
| 229 | struct extended_perms_decision *xpd; |
| 230 | |
| 231 | xpd = &xpd_node->xpd; |
| 232 | if (xpd->allowed) |
| 233 | kmem_cache_free(avc_xperms_data_cachep, xpd->allowed); |
| 234 | if (xpd->auditallow) |
| 235 | kmem_cache_free(avc_xperms_data_cachep, xpd->auditallow); |
| 236 | if (xpd->dontaudit) |
| 237 | kmem_cache_free(avc_xperms_data_cachep, xpd->dontaudit); |
| 238 | kmem_cache_free(avc_xperms_decision_cachep, xpd_node); |
| 239 | } |
| 240 | |
| 241 | static void avc_xperms_free(struct avc_xperms_node *xp_node) |
| 242 | { |
| 243 | struct avc_xperms_decision_node *xpd_node, *tmp; |
| 244 | |
| 245 | if (!xp_node) |
| 246 | return; |
| 247 | |
| 248 | list_for_each_entry_safe(xpd_node, tmp, &xp_node->xpd_head, xpd_list) { |
| 249 | list_del(&xpd_node->xpd_list); |
| 250 | avc_xperms_decision_free(xpd_node); |
| 251 | } |
| 252 | kmem_cache_free(avc_xperms_cachep, xp_node); |
| 253 | } |
| 254 | |
| 255 | static void avc_copy_xperms_decision(struct extended_perms_decision *dest, |
| 256 | struct extended_perms_decision *src) |
| 257 | { |
| 258 | dest->driver = src->driver; |
| 259 | dest->used = src->used; |
| 260 | if (dest->used & XPERMS_ALLOWED) |
| 261 | memcpy(dest->allowed->p, src->allowed->p, |
| 262 | sizeof(src->allowed->p)); |
| 263 | if (dest->used & XPERMS_AUDITALLOW) |
| 264 | memcpy(dest->auditallow->p, src->auditallow->p, |
| 265 | sizeof(src->auditallow->p)); |
| 266 | if (dest->used & XPERMS_DONTAUDIT) |
| 267 | memcpy(dest->dontaudit->p, src->dontaudit->p, |
| 268 | sizeof(src->dontaudit->p)); |
| 269 | } |
| 270 | |
| 271 | /* |
| 272 | * similar to avc_copy_xperms_decision, but only copy decision |
| 273 | * information relevant to this perm |
| 274 | */ |
| 275 | static inline void avc_quick_copy_xperms_decision(u8 perm, |
| 276 | struct extended_perms_decision *dest, |
| 277 | struct extended_perms_decision *src) |
| 278 | { |
| 279 | /* |
| 280 | * compute index of the u32 of the 256 bits (8 u32s) that contain this |
| 281 | * command permission |
| 282 | */ |
| 283 | u8 i = perm >> 5; |
| 284 | |
| 285 | dest->used = src->used; |
| 286 | if (dest->used & XPERMS_ALLOWED) |
| 287 | dest->allowed->p[i] = src->allowed->p[i]; |
| 288 | if (dest->used & XPERMS_AUDITALLOW) |
| 289 | dest->auditallow->p[i] = src->auditallow->p[i]; |
| 290 | if (dest->used & XPERMS_DONTAUDIT) |
| 291 | dest->dontaudit->p[i] = src->dontaudit->p[i]; |
| 292 | } |
| 293 | |
| 294 | static struct avc_xperms_decision_node |
| 295 | *avc_xperms_decision_alloc(u8 which) |
| 296 | { |
| 297 | struct avc_xperms_decision_node *xpd_node; |
| 298 | struct extended_perms_decision *xpd; |
| 299 | |
Minchan Kim | 648f2c6 | 2021-06-09 09:37:17 -0700 | [diff] [blame] | 300 | xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, |
| 301 | GFP_NOWAIT | __GFP_NOWARN); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 302 | if (!xpd_node) |
| 303 | return NULL; |
| 304 | |
| 305 | xpd = &xpd_node->xpd; |
| 306 | if (which & XPERMS_ALLOWED) { |
| 307 | xpd->allowed = kmem_cache_zalloc(avc_xperms_data_cachep, |
Minchan Kim | 648f2c6 | 2021-06-09 09:37:17 -0700 | [diff] [blame] | 308 | GFP_NOWAIT | __GFP_NOWARN); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 309 | if (!xpd->allowed) |
| 310 | goto error; |
| 311 | } |
| 312 | if (which & XPERMS_AUDITALLOW) { |
| 313 | xpd->auditallow = kmem_cache_zalloc(avc_xperms_data_cachep, |
Minchan Kim | 648f2c6 | 2021-06-09 09:37:17 -0700 | [diff] [blame] | 314 | GFP_NOWAIT | __GFP_NOWARN); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 315 | if (!xpd->auditallow) |
| 316 | goto error; |
| 317 | } |
| 318 | if (which & XPERMS_DONTAUDIT) { |
| 319 | xpd->dontaudit = kmem_cache_zalloc(avc_xperms_data_cachep, |
Minchan Kim | 648f2c6 | 2021-06-09 09:37:17 -0700 | [diff] [blame] | 320 | GFP_NOWAIT | __GFP_NOWARN); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 321 | if (!xpd->dontaudit) |
| 322 | goto error; |
| 323 | } |
| 324 | return xpd_node; |
| 325 | error: |
| 326 | avc_xperms_decision_free(xpd_node); |
| 327 | return NULL; |
| 328 | } |
| 329 | |
| 330 | static int avc_add_xperms_decision(struct avc_node *node, |
| 331 | struct extended_perms_decision *src) |
| 332 | { |
| 333 | struct avc_xperms_decision_node *dest_xpd; |
| 334 | |
| 335 | node->ae.xp_node->xp.len++; |
| 336 | dest_xpd = avc_xperms_decision_alloc(src->used); |
| 337 | if (!dest_xpd) |
| 338 | return -ENOMEM; |
| 339 | avc_copy_xperms_decision(&dest_xpd->xpd, src); |
| 340 | list_add(&dest_xpd->xpd_list, &node->ae.xp_node->xpd_head); |
| 341 | return 0; |
| 342 | } |
| 343 | |
| 344 | static struct avc_xperms_node *avc_xperms_alloc(void) |
| 345 | { |
| 346 | struct avc_xperms_node *xp_node; |
| 347 | |
Minchan Kim | 648f2c6 | 2021-06-09 09:37:17 -0700 | [diff] [blame] | 348 | xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT | __GFP_NOWARN); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 349 | if (!xp_node) |
| 350 | return xp_node; |
| 351 | INIT_LIST_HEAD(&xp_node->xpd_head); |
| 352 | return xp_node; |
| 353 | } |
| 354 | |
| 355 | static int avc_xperms_populate(struct avc_node *node, |
| 356 | struct avc_xperms_node *src) |
| 357 | { |
| 358 | struct avc_xperms_node *dest; |
| 359 | struct avc_xperms_decision_node *dest_xpd; |
| 360 | struct avc_xperms_decision_node *src_xpd; |
| 361 | |
| 362 | if (src->xp.len == 0) |
| 363 | return 0; |
| 364 | dest = avc_xperms_alloc(); |
| 365 | if (!dest) |
| 366 | return -ENOMEM; |
| 367 | |
| 368 | memcpy(dest->xp.drivers.p, src->xp.drivers.p, sizeof(dest->xp.drivers.p)); |
| 369 | dest->xp.len = src->xp.len; |
| 370 | |
| 371 | /* for each source xpd allocate a destination xpd and copy */ |
| 372 | list_for_each_entry(src_xpd, &src->xpd_head, xpd_list) { |
| 373 | dest_xpd = avc_xperms_decision_alloc(src_xpd->xpd.used); |
| 374 | if (!dest_xpd) |
| 375 | goto error; |
| 376 | avc_copy_xperms_decision(&dest_xpd->xpd, &src_xpd->xpd); |
| 377 | list_add(&dest_xpd->xpd_list, &dest->xpd_head); |
| 378 | } |
| 379 | node->ae.xp_node = dest; |
| 380 | return 0; |
| 381 | error: |
| 382 | avc_xperms_free(dest); |
| 383 | return -ENOMEM; |
| 384 | |
| 385 | } |
| 386 | |
| 387 | static inline u32 avc_xperms_audit_required(u32 requested, |
| 388 | struct av_decision *avd, |
| 389 | struct extended_perms_decision *xpd, |
| 390 | u8 perm, |
| 391 | int result, |
| 392 | u32 *deniedp) |
| 393 | { |
| 394 | u32 denied, audited; |
| 395 | |
| 396 | denied = requested & ~avd->allowed; |
| 397 | if (unlikely(denied)) { |
| 398 | audited = denied & avd->auditdeny; |
| 399 | if (audited && xpd) { |
| 400 | if (avc_xperms_has_perm(xpd, perm, XPERMS_DONTAUDIT)) |
| 401 | audited &= ~requested; |
| 402 | } |
| 403 | } else if (result) { |
| 404 | audited = denied = requested; |
| 405 | } else { |
| 406 | audited = requested & avd->auditallow; |
| 407 | if (audited && xpd) { |
| 408 | if (!avc_xperms_has_perm(xpd, perm, XPERMS_AUDITALLOW)) |
| 409 | audited &= ~requested; |
| 410 | } |
| 411 | } |
| 412 | |
| 413 | *deniedp = denied; |
| 414 | return audited; |
| 415 | } |
| 416 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 417 | static inline int avc_xperms_audit(struct selinux_state *state, |
| 418 | u32 ssid, u32 tsid, u16 tclass, |
| 419 | u32 requested, struct av_decision *avd, |
| 420 | struct extended_perms_decision *xpd, |
| 421 | u8 perm, int result, |
| 422 | struct common_audit_data *ad) |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 423 | { |
| 424 | u32 audited, denied; |
| 425 | |
| 426 | audited = avc_xperms_audit_required( |
| 427 | requested, avd, xpd, perm, result, &denied); |
| 428 | if (likely(!audited)) |
| 429 | return 0; |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 430 | return slow_avc_audit(state, ssid, tsid, tclass, requested, |
Stephen Smalley | 0188d5c | 2019-11-22 12:22:45 -0500 | [diff] [blame] | 431 | audited, denied, result, ad); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 432 | } |
| 433 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | static void avc_node_free(struct rcu_head *rhead) |
| 435 | { |
| 436 | struct avc_node *node = container_of(rhead, struct avc_node, rhead); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 437 | avc_xperms_free(node->ae.xp_node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 438 | kmem_cache_free(avc_node_cachep, node); |
| 439 | avc_cache_stats_incr(frees); |
| 440 | } |
| 441 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 442 | static void avc_node_delete(struct selinux_avc *avc, struct avc_node *node) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 443 | { |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 444 | hlist_del_rcu(&node->list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | call_rcu(&node->rhead, avc_node_free); |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 446 | atomic_dec(&avc->avc_cache.active_nodes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | } |
| 448 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 449 | static void avc_node_kill(struct selinux_avc *avc, struct avc_node *node) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 450 | { |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 451 | avc_xperms_free(node->ae.xp_node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | kmem_cache_free(avc_node_cachep, node); |
| 453 | avc_cache_stats_incr(frees); |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 454 | atomic_dec(&avc->avc_cache.active_nodes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | } |
| 456 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 457 | static void avc_node_replace(struct selinux_avc *avc, |
| 458 | struct avc_node *new, struct avc_node *old) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | { |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 460 | hlist_replace_rcu(&old->list, &new->list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 461 | call_rcu(&old->rhead, avc_node_free); |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 462 | atomic_dec(&avc->avc_cache.active_nodes); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | } |
| 464 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 465 | static inline int avc_reclaim_node(struct selinux_avc *avc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 466 | { |
| 467 | struct avc_node *node; |
| 468 | int hvalue, try, ecx; |
| 469 | unsigned long flags; |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 470 | struct hlist_head *head; |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 471 | spinlock_t *lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | |
Eric Paris | 95fff33 | 2008-04-17 14:42:10 -0400 | [diff] [blame] | 473 | for (try = 0, ecx = 0; try < AVC_CACHE_SLOTS; try++) { |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 474 | hvalue = atomic_inc_return(&avc->avc_cache.lru_hint) & |
| 475 | (AVC_CACHE_SLOTS - 1); |
| 476 | head = &avc->avc_cache.slots[hvalue]; |
| 477 | lock = &avc->avc_cache.slots_lock[hvalue]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 478 | |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 479 | if (!spin_trylock_irqsave(lock, flags)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | continue; |
| 481 | |
Paul E. McKenney | 6184425 | 2008-04-21 18:12:33 -0700 | [diff] [blame] | 482 | rcu_read_lock(); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 483 | hlist_for_each_entry(node, head, list) { |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 484 | avc_node_delete(avc, node); |
Eric Paris | 906d27d | 2009-02-12 14:50:43 -0500 | [diff] [blame] | 485 | avc_cache_stats_incr(reclaims); |
| 486 | ecx++; |
| 487 | if (ecx >= AVC_CACHE_RECLAIM) { |
| 488 | rcu_read_unlock(); |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 489 | spin_unlock_irqrestore(lock, flags); |
Eric Paris | 906d27d | 2009-02-12 14:50:43 -0500 | [diff] [blame] | 490 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 491 | } |
| 492 | } |
Paul E. McKenney | 6184425 | 2008-04-21 18:12:33 -0700 | [diff] [blame] | 493 | rcu_read_unlock(); |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 494 | spin_unlock_irqrestore(lock, flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 495 | } |
| 496 | out: |
| 497 | return ecx; |
| 498 | } |
| 499 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 500 | static struct avc_node *avc_alloc_node(struct selinux_avc *avc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 501 | { |
| 502 | struct avc_node *node; |
| 503 | |
Minchan Kim | 648f2c6 | 2021-06-09 09:37:17 -0700 | [diff] [blame] | 504 | node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT | __GFP_NOWARN); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 505 | if (!node) |
| 506 | goto out; |
| 507 | |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 508 | INIT_HLIST_NODE(&node->list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 509 | avc_cache_stats_incr(allocations); |
| 510 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 511 | if (atomic_inc_return(&avc->avc_cache.active_nodes) > |
| 512 | avc->avc_cache_threshold) |
| 513 | avc_reclaim_node(avc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 514 | |
| 515 | out: |
| 516 | return node; |
| 517 | } |
| 518 | |
Eric Paris | 21193dc | 2009-02-12 14:50:49 -0500 | [diff] [blame] | 519 | static void avc_node_populate(struct avc_node *node, u32 ssid, u32 tsid, u16 tclass, struct av_decision *avd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | { |
| 521 | node->ae.ssid = ssid; |
| 522 | node->ae.tsid = tsid; |
| 523 | node->ae.tclass = tclass; |
Eric Paris | 21193dc | 2009-02-12 14:50:49 -0500 | [diff] [blame] | 524 | memcpy(&node->ae.avd, avd, sizeof(node->ae.avd)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 525 | } |
| 526 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 527 | static inline struct avc_node *avc_search_node(struct selinux_avc *avc, |
| 528 | u32 ssid, u32 tsid, u16 tclass) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 529 | { |
| 530 | struct avc_node *node, *ret = NULL; |
| 531 | int hvalue; |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 532 | struct hlist_head *head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 533 | |
| 534 | hvalue = avc_hash(ssid, tsid, tclass); |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 535 | head = &avc->avc_cache.slots[hvalue]; |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 536 | hlist_for_each_entry_rcu(node, head, list) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | if (ssid == node->ae.ssid && |
| 538 | tclass == node->ae.tclass && |
| 539 | tsid == node->ae.tsid) { |
| 540 | ret = node; |
| 541 | break; |
| 542 | } |
| 543 | } |
| 544 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | return ret; |
| 546 | } |
| 547 | |
| 548 | /** |
| 549 | * avc_lookup - Look up an AVC entry. |
Paul Moore | e9fd729 | 2020-11-18 21:15:08 -0500 | [diff] [blame] | 550 | * @avc: the access vector cache |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | * @ssid: source security identifier |
| 552 | * @tsid: target security identifier |
| 553 | * @tclass: target security class |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | * |
| 555 | * Look up an AVC entry that is valid for the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | * (@ssid, @tsid), interpreting the permissions |
| 557 | * based on @tclass. If a valid AVC entry exists, |
Justin P. Mattock | 6382dc3 | 2010-01-14 23:03:18 -0800 | [diff] [blame] | 558 | * then this function returns the avc_node. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 559 | * Otherwise, this function returns NULL. |
| 560 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 561 | static struct avc_node *avc_lookup(struct selinux_avc *avc, |
| 562 | u32 ssid, u32 tsid, u16 tclass) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | { |
| 564 | struct avc_node *node; |
| 565 | |
| 566 | avc_cache_stats_incr(lookups); |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 567 | node = avc_search_node(avc, ssid, tsid, tclass); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 568 | |
Eric Paris | f1c6381 | 2009-02-12 14:50:54 -0500 | [diff] [blame] | 569 | if (node) |
Linus Torvalds | 257313b | 2011-05-19 21:22:53 -0700 | [diff] [blame] | 570 | return node; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 571 | |
Linus Torvalds | 257313b | 2011-05-19 21:22:53 -0700 | [diff] [blame] | 572 | avc_cache_stats_incr(misses); |
| 573 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 574 | } |
| 575 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 576 | static int avc_latest_notif_update(struct selinux_avc *avc, |
| 577 | int seqno, int is_insert) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 578 | { |
| 579 | int ret = 0; |
| 580 | static DEFINE_SPINLOCK(notif_lock); |
| 581 | unsigned long flag; |
| 582 | |
| 583 | spin_lock_irqsave(¬if_lock, flag); |
| 584 | if (is_insert) { |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 585 | if (seqno < avc->avc_cache.latest_notif) { |
peter enderborg | 07c81ac | 2018-06-12 10:09:11 +0200 | [diff] [blame] | 586 | pr_warn("SELinux: avc: seqno %d < latest_notif %d\n", |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 587 | seqno, avc->avc_cache.latest_notif); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 588 | ret = -EAGAIN; |
| 589 | } |
| 590 | } else { |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 591 | if (seqno > avc->avc_cache.latest_notif) |
| 592 | avc->avc_cache.latest_notif = seqno; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 593 | } |
| 594 | spin_unlock_irqrestore(¬if_lock, flag); |
| 595 | |
| 596 | return ret; |
| 597 | } |
| 598 | |
| 599 | /** |
| 600 | * avc_insert - Insert an AVC entry. |
Paul Moore | e9fd729 | 2020-11-18 21:15:08 -0500 | [diff] [blame] | 601 | * @avc: the access vector cache |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 602 | * @ssid: source security identifier |
| 603 | * @tsid: target security identifier |
| 604 | * @tclass: target security class |
Eric Paris | 21193dc | 2009-02-12 14:50:49 -0500 | [diff] [blame] | 605 | * @avd: resulting av decision |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 606 | * @xp_node: resulting extended permissions |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | * |
| 608 | * Insert an AVC entry for the SID pair |
| 609 | * (@ssid, @tsid) and class @tclass. |
| 610 | * The access vectors and the sequence number are |
| 611 | * normally provided by the security server in |
| 612 | * response to a security_compute_av() call. If the |
Eric Paris | 21193dc | 2009-02-12 14:50:49 -0500 | [diff] [blame] | 613 | * sequence number @avd->seqno is not less than the latest |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | * revocation notification, then the function copies |
| 615 | * the access vectors into a cache entry, returns |
| 616 | * avc_node inserted. Otherwise, this function returns NULL. |
| 617 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 618 | static struct avc_node *avc_insert(struct selinux_avc *avc, |
| 619 | u32 ssid, u32 tsid, u16 tclass, |
| 620 | struct av_decision *avd, |
| 621 | struct avc_xperms_node *xp_node) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | { |
| 623 | struct avc_node *pos, *node = NULL; |
| 624 | int hvalue; |
| 625 | unsigned long flag; |
Paul Moore | d8db60c | 2019-12-09 20:39:46 -0500 | [diff] [blame] | 626 | spinlock_t *lock; |
| 627 | struct hlist_head *head; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 628 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 629 | if (avc_latest_notif_update(avc, avd->seqno, 1)) |
Paul Moore | d8db60c | 2019-12-09 20:39:46 -0500 | [diff] [blame] | 630 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 631 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 632 | node = avc_alloc_node(avc); |
Paul Moore | d8db60c | 2019-12-09 20:39:46 -0500 | [diff] [blame] | 633 | if (!node) |
| 634 | return NULL; |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 635 | |
Paul Moore | d8db60c | 2019-12-09 20:39:46 -0500 | [diff] [blame] | 636 | avc_node_populate(node, ssid, tsid, tclass, avd); |
| 637 | if (avc_xperms_populate(node, xp_node)) { |
| 638 | avc_node_kill(avc, node); |
| 639 | return NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | } |
Paul Moore | d8db60c | 2019-12-09 20:39:46 -0500 | [diff] [blame] | 641 | |
| 642 | hvalue = avc_hash(ssid, tsid, tclass); |
| 643 | head = &avc->avc_cache.slots[hvalue]; |
| 644 | lock = &avc->avc_cache.slots_lock[hvalue]; |
| 645 | spin_lock_irqsave(lock, flag); |
| 646 | hlist_for_each_entry(pos, head, list) { |
| 647 | if (pos->ae.ssid == ssid && |
| 648 | pos->ae.tsid == tsid && |
| 649 | pos->ae.tclass == tclass) { |
| 650 | avc_node_replace(avc, node, pos); |
| 651 | goto found; |
| 652 | } |
| 653 | } |
| 654 | hlist_add_head_rcu(&node->list, head); |
| 655 | found: |
| 656 | spin_unlock_irqrestore(lock, flag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 657 | return node; |
| 658 | } |
| 659 | |
Thomas Liu | 2bf4969 | 2009-07-14 12:14:09 -0400 | [diff] [blame] | 660 | /** |
| 661 | * avc_audit_pre_callback - SELinux specific information |
| 662 | * will be called by generic audit code |
| 663 | * @ab: the audit buffer |
| 664 | * @a: audit_data |
| 665 | */ |
| 666 | static void avc_audit_pre_callback(struct audit_buffer *ab, void *a) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | { |
Thomas Liu | 2bf4969 | 2009-07-14 12:14:09 -0400 | [diff] [blame] | 668 | struct common_audit_data *ad = a; |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 669 | struct selinux_audit_data *sad = ad->selinux_audit_data; |
| 670 | u32 av = sad->audited; |
Christian Gƶttsche | ded3457 | 2022-05-02 16:43:38 +0200 | [diff] [blame] | 671 | const char *const *perms; |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 672 | int i, perm; |
| 673 | |
| 674 | audit_log_format(ab, "avc: %s ", sad->denied ? "denied" : "granted"); |
| 675 | |
| 676 | if (av == 0) { |
Stephen Smalley | 45189a1 | 2019-02-05 11:49:32 -0500 | [diff] [blame] | 677 | audit_log_format(ab, " null"); |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 678 | return; |
| 679 | } |
| 680 | |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 681 | perms = secclass_map[sad->tclass-1].perms; |
| 682 | |
Stephen Smalley | 45189a1 | 2019-02-05 11:49:32 -0500 | [diff] [blame] | 683 | audit_log_format(ab, " {"); |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 684 | i = 0; |
| 685 | perm = 1; |
| 686 | while (i < (sizeof(av) * 8)) { |
| 687 | if ((perm & av) && perms[i]) { |
| 688 | audit_log_format(ab, " %s", perms[i]); |
| 689 | av &= ~perm; |
| 690 | } |
| 691 | i++; |
| 692 | perm <<= 1; |
| 693 | } |
| 694 | |
| 695 | if (av) |
| 696 | audit_log_format(ab, " 0x%x", av); |
| 697 | |
Stephen Smalley | 45189a1 | 2019-02-05 11:49:32 -0500 | [diff] [blame] | 698 | audit_log_format(ab, " } for "); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 699 | } |
| 700 | |
Thomas Liu | 2bf4969 | 2009-07-14 12:14:09 -0400 | [diff] [blame] | 701 | /** |
| 702 | * avc_audit_post_callback - SELinux specific information |
| 703 | * will be called by generic audit code |
| 704 | * @ab: the audit buffer |
| 705 | * @a: audit_data |
| 706 | */ |
| 707 | static void avc_audit_post_callback(struct audit_buffer *ab, void *a) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 708 | { |
Thomas Liu | 2bf4969 | 2009-07-14 12:14:09 -0400 | [diff] [blame] | 709 | struct common_audit_data *ad = a; |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 710 | struct selinux_audit_data *sad = ad->selinux_audit_data; |
Peter Enderborg | 30969bc | 2020-08-21 16:08:22 +0200 | [diff] [blame] | 711 | char *scontext = NULL; |
| 712 | char *tcontext = NULL; |
| 713 | const char *tclass = NULL; |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 714 | u32 scontext_len; |
Peter Enderborg | 30969bc | 2020-08-21 16:08:22 +0200 | [diff] [blame] | 715 | u32 tcontext_len; |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 716 | int rc; |
| 717 | |
| 718 | rc = security_sid_to_context(sad->state, sad->ssid, &scontext, |
| 719 | &scontext_len); |
| 720 | if (rc) |
| 721 | audit_log_format(ab, " ssid=%d", sad->ssid); |
Peter Enderborg | 30969bc | 2020-08-21 16:08:22 +0200 | [diff] [blame] | 722 | else |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 723 | audit_log_format(ab, " scontext=%s", scontext); |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 724 | |
Peter Enderborg | 30969bc | 2020-08-21 16:08:22 +0200 | [diff] [blame] | 725 | rc = security_sid_to_context(sad->state, sad->tsid, &tcontext, |
| 726 | &tcontext_len); |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 727 | if (rc) |
| 728 | audit_log_format(ab, " tsid=%d", sad->tsid); |
Peter Enderborg | 30969bc | 2020-08-21 16:08:22 +0200 | [diff] [blame] | 729 | else |
| 730 | audit_log_format(ab, " tcontext=%s", tcontext); |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 731 | |
Peter Enderborg | 30969bc | 2020-08-21 16:08:22 +0200 | [diff] [blame] | 732 | tclass = secclass_map[sad->tclass-1].name; |
| 733 | audit_log_format(ab, " tclass=%s", tclass); |
Ondrej Mosnacek | a2c5138 | 2019-01-25 11:06:48 +0100 | [diff] [blame] | 734 | |
| 735 | if (sad->denied) |
| 736 | audit_log_format(ab, " permissive=%u", sad->result ? 0 : 1); |
Ondrej Mosnacek | fede148 | 2019-01-25 11:06:51 +0100 | [diff] [blame] | 737 | |
Peter Enderborg | 30969bc | 2020-08-21 16:08:22 +0200 | [diff] [blame] | 738 | trace_selinux_audited(sad, scontext, tcontext, tclass); |
| 739 | kfree(tcontext); |
| 740 | kfree(scontext); |
| 741 | |
Ondrej Mosnacek | fede148 | 2019-01-25 11:06:51 +0100 | [diff] [blame] | 742 | /* in case of invalid context report also the actual context string */ |
| 743 | rc = security_sid_to_context_inval(sad->state, sad->ssid, &scontext, |
| 744 | &scontext_len); |
| 745 | if (!rc && scontext) { |
Ondrej Mosnacek | aff7ed4 | 2019-06-11 10:07:19 +0200 | [diff] [blame] | 746 | if (scontext_len && scontext[scontext_len - 1] == '\0') |
| 747 | scontext_len--; |
| 748 | audit_log_format(ab, " srawcon="); |
| 749 | audit_log_n_untrustedstring(ab, scontext, scontext_len); |
Ondrej Mosnacek | fede148 | 2019-01-25 11:06:51 +0100 | [diff] [blame] | 750 | kfree(scontext); |
| 751 | } |
| 752 | |
| 753 | rc = security_sid_to_context_inval(sad->state, sad->tsid, &scontext, |
| 754 | &scontext_len); |
| 755 | if (!rc && scontext) { |
Ondrej Mosnacek | aff7ed4 | 2019-06-11 10:07:19 +0200 | [diff] [blame] | 756 | if (scontext_len && scontext[scontext_len - 1] == '\0') |
| 757 | scontext_len--; |
| 758 | audit_log_format(ab, " trawcon="); |
| 759 | audit_log_n_untrustedstring(ab, scontext, scontext_len); |
Ondrej Mosnacek | fede148 | 2019-01-25 11:06:51 +0100 | [diff] [blame] | 760 | kfree(scontext); |
| 761 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | } |
| 763 | |
Al Viro | b17ec22 | 2021-01-16 15:40:54 -0500 | [diff] [blame] | 764 | /* |
| 765 | * This is the slow part of avc audit with big stack footprint. |
| 766 | * Note that it is non-blocking and can be called from under |
| 767 | * rcu_read_lock(). |
| 768 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 769 | noinline int slow_avc_audit(struct selinux_state *state, |
| 770 | u32 ssid, u32 tsid, u16 tclass, |
| 771 | u32 requested, u32 audited, u32 denied, int result, |
Stephen Smalley | 0188d5c | 2019-11-22 12:22:45 -0500 | [diff] [blame] | 772 | struct common_audit_data *a) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 773 | { |
Thomas Liu | 2bf4969 | 2009-07-14 12:14:09 -0400 | [diff] [blame] | 774 | struct common_audit_data stack_data; |
Eric Paris | 899838b | 2012-04-04 15:01:43 -0400 | [diff] [blame] | 775 | struct selinux_audit_data sad; |
Eric Paris | 9ade0cf | 2011-04-25 16:26:29 -0400 | [diff] [blame] | 776 | |
Ondrej Mosnacek | 994fb06 | 2019-01-25 11:06:49 +0100 | [diff] [blame] | 777 | if (WARN_ON(!tclass || tclass >= ARRAY_SIZE(secclass_map))) |
| 778 | return -EINVAL; |
| 779 | |
Thomas Liu | 2bf4969 | 2009-07-14 12:14:09 -0400 | [diff] [blame] | 780 | if (!a) { |
| 781 | a = &stack_data; |
Eric Paris | 50c205f | 2012-04-04 15:01:43 -0400 | [diff] [blame] | 782 | a->type = LSM_AUDIT_DATA_NONE; |
James Morris | be940d6 | 2009-07-13 10:39:36 +1000 | [diff] [blame] | 783 | } |
Eric Paris | 9ade0cf | 2011-04-25 16:26:29 -0400 | [diff] [blame] | 784 | |
Eric Paris | 899838b | 2012-04-04 15:01:43 -0400 | [diff] [blame] | 785 | sad.tclass = tclass; |
| 786 | sad.requested = requested; |
| 787 | sad.ssid = ssid; |
| 788 | sad.tsid = tsid; |
| 789 | sad.audited = audited; |
| 790 | sad.denied = denied; |
Stephen Smalley | ca7786a | 2014-04-29 11:29:04 -0700 | [diff] [blame] | 791 | sad.result = result; |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 792 | sad.state = state; |
Eric Paris | 3f0882c | 2012-04-03 09:38:00 -0700 | [diff] [blame] | 793 | |
Eric Paris | 899838b | 2012-04-04 15:01:43 -0400 | [diff] [blame] | 794 | a->selinux_audit_data = &sad; |
| 795 | |
Linus Torvalds | b61c37f | 2012-04-02 15:48:12 -0700 | [diff] [blame] | 796 | common_lsm_audit(a, avc_audit_pre_callback, avc_audit_post_callback); |
Eric Paris | 9ade0cf | 2011-04-25 16:26:29 -0400 | [diff] [blame] | 797 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | } |
| 799 | |
| 800 | /** |
| 801 | * avc_add_callback - Register a callback for security events. |
| 802 | * @callback: callback function |
| 803 | * @events: security events |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 804 | * |
Wanlong Gao | 562c99f | 2012-03-07 22:17:14 +0800 | [diff] [blame] | 805 | * Register a callback function for events in the set @events. |
| 806 | * Returns %0 on success or -%ENOMEM if insufficient memory |
| 807 | * exists to add the callback. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | */ |
Wanlong Gao | 562c99f | 2012-03-07 22:17:14 +0800 | [diff] [blame] | 809 | int __init avc_add_callback(int (*callback)(u32 event), u32 events) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | { |
| 811 | struct avc_callback_node *c; |
| 812 | int rc = 0; |
| 813 | |
Wanlong Gao | 0b36e44 | 2012-03-07 22:17:13 +0800 | [diff] [blame] | 814 | c = kmalloc(sizeof(*c), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | if (!c) { |
| 816 | rc = -ENOMEM; |
| 817 | goto out; |
| 818 | } |
| 819 | |
| 820 | c->callback = callback; |
| 821 | c->events = events; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 822 | c->next = avc_callbacks; |
| 823 | avc_callbacks = c; |
| 824 | out: |
| 825 | return rc; |
| 826 | } |
| 827 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 828 | /** |
Souptick Joarder | 7cffc37 | 2021-04-25 14:05:37 +0530 | [diff] [blame] | 829 | * avc_update_node - Update an AVC entry |
Paul Moore | e9fd729 | 2020-11-18 21:15:08 -0500 | [diff] [blame] | 830 | * @avc: the access vector cache |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 831 | * @event : Updating event |
| 832 | * @perms : Permission mask bits |
Paul Moore | e9fd729 | 2020-11-18 21:15:08 -0500 | [diff] [blame] | 833 | * @driver: xperm driver information |
| 834 | * @xperm: xperm permissions |
| 835 | * @ssid: AVC entry source sid |
| 836 | * @tsid: AVC entry target sid |
| 837 | * @tclass : AVC entry target object class |
Eric Paris | a5dda683 | 2009-02-12 14:50:11 -0500 | [diff] [blame] | 838 | * @seqno : sequence number when decision was made |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 839 | * @xpd: extended_perms_decision to be added to the node |
Al Viro | b17ec22 | 2021-01-16 15:40:54 -0500 | [diff] [blame] | 840 | * @flags: the AVC_* flags, e.g. AVC_EXTENDED_PERMS, or 0. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | * |
| 842 | * if a valid AVC entry doesn't exist,this function returns -ENOENT. |
| 843 | * if kmalloc() called internal returns NULL, this function returns -ENOMEM. |
Justin P. Mattock | 6382dc3 | 2010-01-14 23:03:18 -0800 | [diff] [blame] | 844 | * otherwise, this function updates the AVC entry. The original AVC-entry object |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | * will release later by RCU. |
| 846 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 847 | static int avc_update_node(struct selinux_avc *avc, |
| 848 | u32 event, u32 perms, u8 driver, u8 xperm, u32 ssid, |
| 849 | u32 tsid, u16 tclass, u32 seqno, |
| 850 | struct extended_perms_decision *xpd, |
| 851 | u32 flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 852 | { |
| 853 | int hvalue, rc = 0; |
| 854 | unsigned long flag; |
| 855 | struct avc_node *pos, *node, *orig = NULL; |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 856 | struct hlist_head *head; |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 857 | spinlock_t *lock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 859 | node = avc_alloc_node(avc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 860 | if (!node) { |
| 861 | rc = -ENOMEM; |
| 862 | goto out; |
| 863 | } |
| 864 | |
| 865 | /* Lock the target slot */ |
| 866 | hvalue = avc_hash(ssid, tsid, tclass); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 867 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 868 | head = &avc->avc_cache.slots[hvalue]; |
| 869 | lock = &avc->avc_cache.slots_lock[hvalue]; |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 870 | |
| 871 | spin_lock_irqsave(lock, flag); |
| 872 | |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 873 | hlist_for_each_entry(pos, head, list) { |
Eric Paris | 95fff33 | 2008-04-17 14:42:10 -0400 | [diff] [blame] | 874 | if (ssid == pos->ae.ssid && |
| 875 | tsid == pos->ae.tsid && |
Eric Paris | a5dda683 | 2009-02-12 14:50:11 -0500 | [diff] [blame] | 876 | tclass == pos->ae.tclass && |
| 877 | seqno == pos->ae.avd.seqno){ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 878 | orig = pos; |
| 879 | break; |
| 880 | } |
| 881 | } |
| 882 | |
| 883 | if (!orig) { |
| 884 | rc = -ENOENT; |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 885 | avc_node_kill(avc, node); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 886 | goto out_unlock; |
| 887 | } |
| 888 | |
| 889 | /* |
| 890 | * Copy and replace original node. |
| 891 | */ |
| 892 | |
Eric Paris | 21193dc | 2009-02-12 14:50:49 -0500 | [diff] [blame] | 893 | avc_node_populate(node, ssid, tsid, tclass, &orig->ae.avd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 894 | |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 895 | if (orig->ae.xp_node) { |
| 896 | rc = avc_xperms_populate(node, orig->ae.xp_node); |
| 897 | if (rc) { |
Jaihind Yadav | 030b995 | 2019-12-17 17:25:47 +0530 | [diff] [blame] | 898 | avc_node_kill(avc, node); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 899 | goto out_unlock; |
| 900 | } |
| 901 | } |
| 902 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | switch (event) { |
| 904 | case AVC_CALLBACK_GRANT: |
| 905 | node->ae.avd.allowed |= perms; |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 906 | if (node->ae.xp_node && (flags & AVC_EXTENDED_PERMS)) |
| 907 | avc_xperms_allow_perm(node->ae.xp_node, driver, xperm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 908 | break; |
| 909 | case AVC_CALLBACK_TRY_REVOKE: |
| 910 | case AVC_CALLBACK_REVOKE: |
| 911 | node->ae.avd.allowed &= ~perms; |
| 912 | break; |
| 913 | case AVC_CALLBACK_AUDITALLOW_ENABLE: |
| 914 | node->ae.avd.auditallow |= perms; |
| 915 | break; |
| 916 | case AVC_CALLBACK_AUDITALLOW_DISABLE: |
| 917 | node->ae.avd.auditallow &= ~perms; |
| 918 | break; |
| 919 | case AVC_CALLBACK_AUDITDENY_ENABLE: |
| 920 | node->ae.avd.auditdeny |= perms; |
| 921 | break; |
| 922 | case AVC_CALLBACK_AUDITDENY_DISABLE: |
| 923 | node->ae.avd.auditdeny &= ~perms; |
| 924 | break; |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 925 | case AVC_CALLBACK_ADD_XPERMS: |
| 926 | avc_add_xperms_decision(node, xpd); |
| 927 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 928 | } |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 929 | avc_node_replace(avc, node, orig); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 930 | out_unlock: |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 931 | spin_unlock_irqrestore(lock, flag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 932 | out: |
| 933 | return rc; |
| 934 | } |
| 935 | |
| 936 | /** |
Eric Paris | 008574b | 2009-09-12 22:54:17 -0400 | [diff] [blame] | 937 | * avc_flush - Flush the cache |
Paul Moore | e9fd729 | 2020-11-18 21:15:08 -0500 | [diff] [blame] | 938 | * @avc: the access vector cache |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 939 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 940 | static void avc_flush(struct selinux_avc *avc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 941 | { |
Eric Paris | 2603665 | 2009-02-12 14:51:04 -0500 | [diff] [blame] | 942 | struct hlist_head *head; |
Eric Paris | 008574b | 2009-09-12 22:54:17 -0400 | [diff] [blame] | 943 | struct avc_node *node; |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 944 | spinlock_t *lock; |
Eric Paris | 008574b | 2009-09-12 22:54:17 -0400 | [diff] [blame] | 945 | unsigned long flag; |
| 946 | int i; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | |
| 948 | for (i = 0; i < AVC_CACHE_SLOTS; i++) { |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 949 | head = &avc->avc_cache.slots[i]; |
| 950 | lock = &avc->avc_cache.slots_lock[i]; |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 951 | |
| 952 | spin_lock_irqsave(lock, flag); |
Paul E. McKenney | 6184425 | 2008-04-21 18:12:33 -0700 | [diff] [blame] | 953 | /* |
| 954 | * With preemptable RCU, the outer spinlock does not |
| 955 | * prevent RCU grace periods from ending. |
| 956 | */ |
| 957 | rcu_read_lock(); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 958 | hlist_for_each_entry(node, head, list) |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 959 | avc_node_delete(avc, node); |
Paul E. McKenney | 6184425 | 2008-04-21 18:12:33 -0700 | [diff] [blame] | 960 | rcu_read_unlock(); |
Eric Paris | edf3d1a | 2009-02-12 14:50:59 -0500 | [diff] [blame] | 961 | spin_unlock_irqrestore(lock, flag); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 962 | } |
Eric Paris | 008574b | 2009-09-12 22:54:17 -0400 | [diff] [blame] | 963 | } |
| 964 | |
| 965 | /** |
| 966 | * avc_ss_reset - Flush the cache and revalidate migrated permissions. |
Paul Moore | e9fd729 | 2020-11-18 21:15:08 -0500 | [diff] [blame] | 967 | * @avc: the access vector cache |
Eric Paris | 008574b | 2009-09-12 22:54:17 -0400 | [diff] [blame] | 968 | * @seqno: policy sequence number |
| 969 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 970 | int avc_ss_reset(struct selinux_avc *avc, u32 seqno) |
Eric Paris | 008574b | 2009-09-12 22:54:17 -0400 | [diff] [blame] | 971 | { |
| 972 | struct avc_callback_node *c; |
| 973 | int rc = 0, tmprc; |
| 974 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 975 | avc_flush(avc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 976 | |
| 977 | for (c = avc_callbacks; c; c = c->next) { |
| 978 | if (c->events & AVC_CALLBACK_RESET) { |
Wanlong Gao | 562c99f | 2012-03-07 22:17:14 +0800 | [diff] [blame] | 979 | tmprc = c->callback(AVC_CALLBACK_RESET); |
Darrel Goeddel | 376bd9c | 2006-02-24 15:44:05 -0600 | [diff] [blame] | 980 | /* save the first error encountered for the return |
| 981 | value and continue processing the callbacks */ |
| 982 | if (!rc) |
| 983 | rc = tmprc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | } |
| 985 | } |
| 986 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 987 | avc_latest_notif_update(avc, seqno, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 988 | return rc; |
| 989 | } |
| 990 | |
Linus Torvalds | a554bea | 2012-03-31 10:58:08 -0700 | [diff] [blame] | 991 | /* |
| 992 | * Slow-path helper function for avc_has_perm_noaudit, |
| 993 | * when the avc_node lookup fails. We get called with |
| 994 | * the RCU read lock held, and need to return with it |
| 995 | * still held, but drop if for the security compute. |
| 996 | * |
| 997 | * Don't inline this, since it's the slow-path and just |
| 998 | * results in a bigger stack frame. |
| 999 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1000 | static noinline |
| 1001 | struct avc_node *avc_compute_av(struct selinux_state *state, |
| 1002 | u32 ssid, u32 tsid, |
| 1003 | u16 tclass, struct av_decision *avd, |
| 1004 | struct avc_xperms_node *xp_node) |
Linus Torvalds | a554bea | 2012-03-31 10:58:08 -0700 | [diff] [blame] | 1005 | { |
| 1006 | rcu_read_unlock(); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1007 | INIT_LIST_HEAD(&xp_node->xpd_head); |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1008 | security_compute_av(state, ssid, tsid, tclass, avd, &xp_node->xp); |
Linus Torvalds | a554bea | 2012-03-31 10:58:08 -0700 | [diff] [blame] | 1009 | rcu_read_lock(); |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1010 | return avc_insert(state->avc, ssid, tsid, tclass, avd, xp_node); |
Linus Torvalds | a554bea | 2012-03-31 10:58:08 -0700 | [diff] [blame] | 1011 | } |
| 1012 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1013 | static noinline int avc_denied(struct selinux_state *state, |
| 1014 | u32 ssid, u32 tsid, |
| 1015 | u16 tclass, u32 requested, |
| 1016 | u8 driver, u8 xperm, unsigned int flags, |
| 1017 | struct av_decision *avd) |
Linus Torvalds | a554bea | 2012-03-31 10:58:08 -0700 | [diff] [blame] | 1018 | { |
| 1019 | if (flags & AVC_STRICT) |
| 1020 | return -EACCES; |
| 1021 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1022 | if (enforcing_enabled(state) && |
Stephen Smalley | aa8e712 | 2018-03-01 18:48:02 -0500 | [diff] [blame] | 1023 | !(avd->flags & AVD_FLAGS_PERMISSIVE)) |
Linus Torvalds | a554bea | 2012-03-31 10:58:08 -0700 | [diff] [blame] | 1024 | return -EACCES; |
| 1025 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1026 | avc_update_node(state->avc, AVC_CALLBACK_GRANT, requested, driver, |
| 1027 | xperm, ssid, tsid, tclass, avd->seqno, NULL, flags); |
Linus Torvalds | a554bea | 2012-03-31 10:58:08 -0700 | [diff] [blame] | 1028 | return 0; |
| 1029 | } |
| 1030 | |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1031 | /* |
| 1032 | * The avc extended permissions logic adds an additional 256 bits of |
| 1033 | * permissions to an avc node when extended permissions for that node are |
| 1034 | * specified in the avtab. If the additional 256 permissions is not adequate, |
| 1035 | * as-is the case with ioctls, then multiple may be chained together and the |
| 1036 | * driver field is used to specify which set contains the permission. |
| 1037 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1038 | int avc_has_extended_perms(struct selinux_state *state, |
| 1039 | u32 ssid, u32 tsid, u16 tclass, u32 requested, |
| 1040 | u8 driver, u8 xperm, struct common_audit_data *ad) |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1041 | { |
| 1042 | struct avc_node *node; |
| 1043 | struct av_decision avd; |
| 1044 | u32 denied; |
| 1045 | struct extended_perms_decision local_xpd; |
| 1046 | struct extended_perms_decision *xpd = NULL; |
| 1047 | struct extended_perms_data allowed; |
| 1048 | struct extended_perms_data auditallow; |
| 1049 | struct extended_perms_data dontaudit; |
| 1050 | struct avc_xperms_node local_xp_node; |
| 1051 | struct avc_xperms_node *xp_node; |
| 1052 | int rc = 0, rc2; |
| 1053 | |
| 1054 | xp_node = &local_xp_node; |
Ondrej Mosnacek | e6f2f38 | 2019-01-28 16:43:33 +0100 | [diff] [blame] | 1055 | if (WARN_ON(!requested)) |
| 1056 | return -EACCES; |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1057 | |
| 1058 | rcu_read_lock(); |
| 1059 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1060 | node = avc_lookup(state->avc, ssid, tsid, tclass); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1061 | if (unlikely(!node)) { |
Michal Orzel | 0a9876f | 2022-03-31 19:33:57 +0200 | [diff] [blame] | 1062 | avc_compute_av(state, ssid, tsid, tclass, &avd, xp_node); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1063 | } else { |
| 1064 | memcpy(&avd, &node->ae.avd, sizeof(avd)); |
| 1065 | xp_node = node->ae.xp_node; |
| 1066 | } |
| 1067 | /* if extended permissions are not defined, only consider av_decision */ |
| 1068 | if (!xp_node || !xp_node->xp.len) |
| 1069 | goto decision; |
| 1070 | |
| 1071 | local_xpd.allowed = &allowed; |
| 1072 | local_xpd.auditallow = &auditallow; |
| 1073 | local_xpd.dontaudit = &dontaudit; |
| 1074 | |
| 1075 | xpd = avc_xperms_decision_lookup(driver, xp_node); |
| 1076 | if (unlikely(!xpd)) { |
| 1077 | /* |
| 1078 | * Compute the extended_perms_decision only if the driver |
| 1079 | * is flagged |
| 1080 | */ |
| 1081 | if (!security_xperm_test(xp_node->xp.drivers.p, driver)) { |
| 1082 | avd.allowed &= ~requested; |
| 1083 | goto decision; |
| 1084 | } |
| 1085 | rcu_read_unlock(); |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1086 | security_compute_xperms_decision(state, ssid, tsid, tclass, |
| 1087 | driver, &local_xpd); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1088 | rcu_read_lock(); |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1089 | avc_update_node(state->avc, AVC_CALLBACK_ADD_XPERMS, requested, |
| 1090 | driver, xperm, ssid, tsid, tclass, avd.seqno, |
| 1091 | &local_xpd, 0); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1092 | } else { |
| 1093 | avc_quick_copy_xperms_decision(xperm, &local_xpd, xpd); |
| 1094 | } |
| 1095 | xpd = &local_xpd; |
| 1096 | |
| 1097 | if (!avc_xperms_has_perm(xpd, xperm, XPERMS_ALLOWED)) |
| 1098 | avd.allowed &= ~requested; |
| 1099 | |
| 1100 | decision: |
| 1101 | denied = requested & ~(avd.allowed); |
| 1102 | if (unlikely(denied)) |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1103 | rc = avc_denied(state, ssid, tsid, tclass, requested, |
| 1104 | driver, xperm, AVC_EXTENDED_PERMS, &avd); |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1105 | |
| 1106 | rcu_read_unlock(); |
| 1107 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1108 | rc2 = avc_xperms_audit(state, ssid, tsid, tclass, requested, |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1109 | &avd, xpd, xperm, rc, ad); |
| 1110 | if (rc2) |
| 1111 | return rc2; |
| 1112 | return rc; |
| 1113 | } |
Linus Torvalds | a554bea | 2012-03-31 10:58:08 -0700 | [diff] [blame] | 1114 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1115 | /** |
| 1116 | * avc_has_perm_noaudit - Check permissions but perform no auditing. |
Paul Moore | e9fd729 | 2020-11-18 21:15:08 -0500 | [diff] [blame] | 1117 | * @state: SELinux state |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1118 | * @ssid: source security identifier |
| 1119 | * @tsid: target security identifier |
| 1120 | * @tclass: target security class |
| 1121 | * @requested: requested permissions, interpreted based on @tclass |
Al Viro | b17ec22 | 2021-01-16 15:40:54 -0500 | [diff] [blame] | 1122 | * @flags: AVC_STRICT or 0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | * @avd: access vector decisions |
| 1124 | * |
| 1125 | * Check the AVC to determine whether the @requested permissions are granted |
| 1126 | * for the SID pair (@ssid, @tsid), interpreting the permissions |
| 1127 | * based on @tclass, and call the security server on a cache miss to obtain |
| 1128 | * a new decision and add it to the cache. Return a copy of the decisions |
| 1129 | * in @avd. Return %0 if all @requested permissions are granted, |
| 1130 | * -%EACCES if any permissions are denied, or another -errno upon |
| 1131 | * other errors. This function is typically called by avc_has_perm(), |
| 1132 | * but may also be called directly to separate permission checking from |
| 1133 | * auditing, e.g. in cases where a lock must be held for the check but |
| 1134 | * should be released for the auditing. |
| 1135 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1136 | inline int avc_has_perm_noaudit(struct selinux_state *state, |
| 1137 | u32 ssid, u32 tsid, |
| 1138 | u16 tclass, u32 requested, |
| 1139 | unsigned int flags, |
| 1140 | struct av_decision *avd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1141 | { |
| 1142 | struct avc_node *node; |
Jeff Vander Stoep | fa1aa14 | 2015-07-10 17:19:56 -0400 | [diff] [blame] | 1143 | struct avc_xperms_node xp_node; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1144 | int rc = 0; |
| 1145 | u32 denied; |
| 1146 | |
Ondrej Mosnacek | e6f2f38 | 2019-01-28 16:43:33 +0100 | [diff] [blame] | 1147 | if (WARN_ON(!requested)) |
| 1148 | return -EACCES; |
Eric Paris | eda4f69 | 2008-03-11 14:19:34 -0400 | [diff] [blame] | 1149 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1150 | rcu_read_lock(); |
| 1151 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1152 | node = avc_lookup(state->avc, ssid, tsid, tclass); |
Jeff Vander Stoep | 83d4a80 | 2015-02-26 13:54:17 -0800 | [diff] [blame] | 1153 | if (unlikely(!node)) |
Michal Orzel | 0a9876f | 2022-03-31 19:33:57 +0200 | [diff] [blame] | 1154 | avc_compute_av(state, ssid, tsid, tclass, avd, &xp_node); |
Jeff Vander Stoep | 83d4a80 | 2015-02-26 13:54:17 -0800 | [diff] [blame] | 1155 | else |
Linus Torvalds | f01e1af | 2011-05-24 13:48:51 -0700 | [diff] [blame] | 1156 | memcpy(avd, &node->ae.avd, sizeof(*avd)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1157 | |
Eric Paris | 21193dc | 2009-02-12 14:50:49 -0500 | [diff] [blame] | 1158 | denied = requested & ~(avd->allowed); |
Linus Torvalds | a554bea | 2012-03-31 10:58:08 -0700 | [diff] [blame] | 1159 | if (unlikely(denied)) |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1160 | rc = avc_denied(state, ssid, tsid, tclass, requested, 0, 0, |
| 1161 | flags, avd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1162 | |
| 1163 | rcu_read_unlock(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1164 | return rc; |
| 1165 | } |
| 1166 | |
| 1167 | /** |
| 1168 | * avc_has_perm - Check permissions and perform any appropriate auditing. |
Paul Moore | e9fd729 | 2020-11-18 21:15:08 -0500 | [diff] [blame] | 1169 | * @state: SELinux state |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1170 | * @ssid: source security identifier |
| 1171 | * @tsid: target security identifier |
| 1172 | * @tclass: target security class |
| 1173 | * @requested: requested permissions, interpreted based on @tclass |
| 1174 | * @auditdata: auxiliary audit data |
| 1175 | * |
| 1176 | * Check the AVC to determine whether the @requested permissions are granted |
| 1177 | * for the SID pair (@ssid, @tsid), interpreting the permissions |
| 1178 | * based on @tclass, and call the security server on a cache miss to obtain |
| 1179 | * a new decision and add it to the cache. Audit the granting or denial of |
| 1180 | * permissions in accordance with the policy. Return %0 if all @requested |
| 1181 | * permissions are granted, -%EACCES if any permissions are denied, or |
| 1182 | * another -errno upon other errors. |
| 1183 | */ |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1184 | int avc_has_perm(struct selinux_state *state, u32 ssid, u32 tsid, u16 tclass, |
Linus Torvalds | cb4fbe5 | 2013-10-04 12:57:22 -0700 | [diff] [blame] | 1185 | u32 requested, struct common_audit_data *auditdata) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1186 | { |
| 1187 | struct av_decision avd; |
Eric Paris | 9ade0cf | 2011-04-25 16:26:29 -0400 | [diff] [blame] | 1188 | int rc, rc2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1190 | rc = avc_has_perm_noaudit(state, ssid, tsid, tclass, requested, 0, |
| 1191 | &avd); |
Eric Paris | 9ade0cf | 2011-04-25 16:26:29 -0400 | [diff] [blame] | 1192 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1193 | rc2 = avc_audit(state, ssid, tsid, tclass, requested, &avd, rc, |
Al Viro | d99cf13 | 2021-01-16 15:57:49 -0500 | [diff] [blame] | 1194 | auditdata); |
Stephen Smalley | 1a37079 | 2019-11-22 12:22:44 -0500 | [diff] [blame] | 1195 | if (rc2) |
| 1196 | return rc2; |
| 1197 | return rc; |
| 1198 | } |
| 1199 | |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1200 | u32 avc_policy_seqno(struct selinux_state *state) |
Yuichi Nakamura | 788e7dd | 2007-09-14 09:27:07 +0900 | [diff] [blame] | 1201 | { |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1202 | return state->avc->avc_cache.latest_notif; |
Yuichi Nakamura | 788e7dd | 2007-09-14 09:27:07 +0900 | [diff] [blame] | 1203 | } |
Thomas Liu | 89c8657 | 2009-06-24 17:58:05 -0400 | [diff] [blame] | 1204 | |
| 1205 | void avc_disable(void) |
| 1206 | { |
Eric Paris | 5224ee0 | 2009-09-20 21:21:10 -0400 | [diff] [blame] | 1207 | /* |
| 1208 | * If you are looking at this because you have realized that we are |
| 1209 | * not destroying the avc_node_cachep it might be easy to fix, but |
| 1210 | * I don't know the memory barrier semantics well enough to know. It's |
| 1211 | * possible that some other task dereferenced security_ops when |
| 1212 | * it still pointed to selinux operations. If that is the case it's |
| 1213 | * possible that it is about to use the avc and is about to need the |
| 1214 | * avc_node_cachep. I know I could wrap the security.c security_ops call |
| 1215 | * in an rcu_lock, but seriously, it's not worth it. Instead I just flush |
| 1216 | * the cache and get that memory back. |
| 1217 | */ |
| 1218 | if (avc_node_cachep) { |
Stephen Smalley | 6b6bc62 | 2018-03-05 11:47:56 -0500 | [diff] [blame] | 1219 | avc_flush(selinux_state.avc); |
Eric Paris | 5224ee0 | 2009-09-20 21:21:10 -0400 | [diff] [blame] | 1220 | /* kmem_cache_destroy(avc_node_cachep); */ |
| 1221 | } |
Thomas Liu | 89c8657 | 2009-06-24 17:58:05 -0400 | [diff] [blame] | 1222 | } |