diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-23 11:21:04 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-23 11:21:04 -0700 |
commit | 5825a95fe92566ada2292a65de030850b5cff1da (patch) | |
tree | 8e210a297844f6e07e0acb6ee793036a2c692976 /security/selinux | |
parent | 3c6a6910a81eae3566bb5fef6ea0f624382595e6 (diff) | |
parent | 15322a0d90b6fd62ae8f22e5b87f735c3fdfeff7 (diff) |
Merge tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
- Add LSM hooks, and SELinux access control hooks, for dnotify,
fanotify, and inotify watches. This has been discussed with both the
LSM and fs/notify folks and everybody is good with these new hooks.
- The LSM stacking changes missed a few calls to current_security() in
the SELinux code; we fix those and remove current_security() for
good.
- Improve our network object labeling cache so that we always return
the object's label, even when under memory pressure. Previously we
would return an error if we couldn't allocate a new cache entry, now
we always return the label even if we can't create a new cache entry
for it.
- Convert the sidtab atomic_t counter to a normal u32 with
READ/WRITE_ONCE() and memory barrier protection.
- A few patches to policydb.c to clean things up (remove forward
declarations, long lines, bad variable names, etc)
* tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
lsm: remove current_security()
selinux: fix residual uses of current_security() for the SELinux blob
selinux: avoid atomic_t usage in sidtab
fanotify, inotify, dnotify, security: add security hook for fs notifications
selinux: always return a secid from the network caches if we find one
selinux: policydb - rename type_val_to_struct_array
selinux: policydb - fix some checkpatch.pl warnings
selinux: shuffle around policydb.c to get rid of forward declarations
Diffstat (limited to 'security/selinux')
-rw-r--r-- | security/selinux/hooks.c | 49 | ||||
-rw-r--r-- | security/selinux/include/classmap.h | 5 | ||||
-rw-r--r-- | security/selinux/include/objsec.h | 20 | ||||
-rw-r--r-- | security/selinux/netif.c | 31 | ||||
-rw-r--r-- | security/selinux/netnode.c | 30 | ||||
-rw-r--r-- | security/selinux/netport.c | 24 | ||||
-rw-r--r-- | security/selinux/ss/policydb.c | 402 | ||||
-rw-r--r-- | security/selinux/ss/policydb.h | 2 | ||||
-rw-r--r-- | security/selinux/ss/services.c | 6 | ||||
-rw-r--r-- | security/selinux/ss/sidtab.c | 48 | ||||
-rw-r--r-- | security/selinux/ss/sidtab.h | 19 |
11 files changed, 340 insertions, 296 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 74dd46de01b6..9625b99e677f 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -89,6 +89,8 @@ #include <linux/kernfs.h> #include <linux/stringhash.h> /* for hashlen_string() */ #include <uapi/linux/mount.h> +#include <linux/fsnotify.h> +#include <linux/fanotify.h> #include "avc.h" #include "objsec.h" @@ -3275,6 +3277,50 @@ static int selinux_inode_removexattr(struct dentry *dentry, const char *name) return -EACCES; } +static int selinux_path_notify(const struct path *path, u64 mask, + unsigned int obj_type) +{ + int ret; + u32 perm; + + struct common_audit_data ad; + + ad.type = LSM_AUDIT_DATA_PATH; + ad.u.path = *path; + + /* + * Set permission needed based on the type of mark being set. + * Performs an additional check for sb watches. + */ + switch (obj_type) { + case FSNOTIFY_OBJ_TYPE_VFSMOUNT: + perm = FILE__WATCH_MOUNT; + break; + case FSNOTIFY_OBJ_TYPE_SB: + perm = FILE__WATCH_SB; + ret = superblock_has_perm(current_cred(), path->dentry->d_sb, + FILESYSTEM__WATCH, &ad); + if (ret) + return ret; + break; + case FSNOTIFY_OBJ_TYPE_INODE: + perm = FILE__WATCH; + break; + default: + return -EINVAL; + } + + /* blocking watches require the file:watch_with_perm permission */ + if (mask & (ALL_FSNOTIFY_PERM_EVENTS)) + perm |= FILE__WATCH_WITH_PERM; + + /* watches on read-like events need the file:watch_reads permission */ + if (mask & (FS_ACCESS | FS_ACCESS_PERM | FS_CLOSE_NOWRITE)) + perm |= FILE__WATCH_READS; + + return path_has_perm(current_cred(), path, perm); +} + /* * Copy the inode security context value to the user. * @@ -3403,7 +3449,7 @@ static int selinux_inode_copy_up_xattr(const char *name) static int selinux_kernfs_init_security(struct kernfs_node *kn_dir, struct kernfs_node *kn) { - const struct task_security_struct *tsec = current_security(); + const struct task_security_struct *tsec = selinux_cred(current_cred()); u32 parent_sid, newsid, clen; int rc; char *context; @@ -6818,6 +6864,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = { LSM_HOOK_INIT(inode_getsecid, selinux_inode_getsecid), LSM_HOOK_INIT(inode_copy_up, selinux_inode_copy_up), LSM_HOOK_INIT(inode_copy_up_xattr, selinux_inode_copy_up_xattr), + LSM_HOOK_INIT(path_notify, selinux_path_notify), LSM_HOOK_INIT(kernfs_init_security, selinux_kernfs_init_security), diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index 201f7e588a29..32e9b03be3dd 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -7,7 +7,8 @@ #define COMMON_FILE_PERMS COMMON_FILE_SOCK_PERMS, "unlink", "link", \ "rename", "execute", "quotaon", "mounton", "audit_access", \ - "open", "execmod" + "open", "execmod", "watch", "watch_mount", "watch_sb", \ + "watch_with_perm", "watch_reads" #define COMMON_SOCK_PERMS COMMON_FILE_SOCK_PERMS, "bind", "connect", \ "listen", "accept", "getopt", "setopt", "shutdown", "recvfrom", \ @@ -60,7 +61,7 @@ struct security_class_mapping secclass_map[] = { { "filesystem", { "mount", "remount", "unmount", "getattr", "relabelfrom", "relabelto", "associate", "quotamod", - "quotaget", NULL } }, + "quotaget", "watch", NULL } }, { "file", { COMMON_FILE_PERMS, "execute_no_trans", "entrypoint", NULL } }, diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h index 91c5395dd20c..586b7abd0aa7 100644 --- a/security/selinux/include/objsec.h +++ b/security/selinux/include/objsec.h @@ -37,16 +37,6 @@ struct task_security_struct { u32 sockcreate_sid; /* fscreate SID */ }; -/* - * get the subjective security ID of the current task - */ -static inline u32 current_sid(void) -{ - const struct task_security_struct *tsec = current_security(); - - return tsec->sid; -} - enum label_initialized { LABEL_INVALID, /* invalid or not initialized */ LABEL_INITIALIZED, /* initialized */ @@ -185,4 +175,14 @@ static inline struct ipc_security_struct *selinux_ipc( return ipc->security + selinux_blob_sizes.lbs_ipc; } +/* + * get the subjective security ID of the current task + */ +static inline u32 current_sid(void) +{ + const struct task_security_struct *tsec = selinux_cred(current_cred()); + + return tsec->sid; +} + #endif /* _SELINUX_OBJSEC_H_ */ diff --git a/security/selinux/netif.c b/security/selinux/netif.c index 9cb83eeee1d9..e40fecd73752 100644 --- a/security/selinux/netif.c +++ b/security/selinux/netif.c @@ -132,9 +132,9 @@ static void sel_netif_destroy(struct sel_netif *netif) */ static int sel_netif_sid_slow(struct net *ns, int ifindex, u32 *sid) { - int ret; + int ret = 0; struct sel_netif *netif; - struct sel_netif *new = NULL; + struct sel_netif *new; struct net_device *dev; /* NOTE: we always use init's network namespace since we don't @@ -151,32 +151,27 @@ static int sel_netif_sid_slow(struct net *ns, int ifindex, u32 *sid) netif = sel_netif_find(ns, ifindex); if (netif != NULL) { *sid = netif->nsec.sid; - ret = 0; goto out; } - new = kzalloc(sizeof(*new), GFP_ATOMIC); - if (new == NULL) { - ret = -ENOMEM; - goto out; - } - ret = security_netif_sid(&selinux_state, dev->name, &new->nsec.sid); - if (ret != 0) - goto out; - new->nsec.ns = ns; - new->nsec.ifindex = ifindex; - ret = sel_netif_insert(new); + + ret = security_netif_sid(&selinux_state, dev->name, sid); if (ret != 0) goto out; - *sid = new->nsec.sid; + new = kzalloc(sizeof(*new), GFP_ATOMIC); + if (new) { + new->nsec.ns = ns; + new->nsec.ifindex = ifindex; + new->nsec.sid = *sid; + if (sel_netif_insert(new)) + kfree(new); + } out: spin_unlock_bh(&sel_netif_lock); dev_put(dev); - if (unlikely(ret)) { + if (unlikely(ret)) pr_warn("SELinux: failure in %s(), unable to determine network interface label (%d)\n", __func__, ifindex); - kfree(new); - } return ret; } diff --git a/security/selinux/netnode.c b/security/selinux/netnode.c index cae1fcaffd1a..9ab84efa46c7 100644 --- a/security/selinux/netnode.c +++ b/security/selinux/netnode.c @@ -189,9 +189,9 @@ static void sel_netnode_insert(struct sel_netnode *node) */ static int sel_netnode_sid_slow(void *addr, u16 family, u32 *sid) { - int ret = -ENOMEM; + int ret; struct sel_netnode *node; - struct sel_netnode *new = NULL; + struct sel_netnode *new; spin_lock_bh(&sel_netnode_lock); node = sel_netnode_find(addr, family); @@ -200,38 +200,36 @@ static int sel_netnode_sid_slow(void *addr, u16 family, u32 *sid) spin_unlock_bh(&sel_netnode_lock); return 0; } + new = kzalloc(sizeof(*new), GFP_ATOMIC); - if (new == NULL) - goto out; switch (family) { case PF_INET: ret = security_node_sid(&selinux_state, PF_INET, addr, sizeof(struct in_addr), sid); - new->nsec.addr.ipv4 = *(__be32 *)addr; + if (new) + new->nsec.addr.ipv4 = *(__be32 *)addr; break; case PF_INET6: ret = security_node_sid(&selinux_state, PF_INET6, addr, sizeof(struct in6_addr), sid); - new->nsec.addr.ipv6 = *(struct in6_addr *)addr; + if (new) + new->nsec.addr.ipv6 = *(struct in6_addr *)addr; break; default: BUG(); ret = -EINVAL; } - if (ret != 0) - goto out; - - new->nsec.family = family; - new->nsec.sid = *sid; - sel_netnode_insert(new); + if (ret == 0 && new) { + new->nsec.family = family; + new->nsec.sid = *sid; + sel_netnode_insert(new); + } else + kfree(new); -out: spin_unlock_bh(&sel_netnode_lock); - if (unlikely(ret)) { + if (unlikely(ret)) pr_warn("SELinux: failure in %s(), unable to determine network node label\n", __func__); - kfree(new); - } return ret; } diff --git a/security/selinux/netport.c b/security/selinux/netport.c index 364b6d5b8968..3f8b2c0458c8 100644 --- a/security/selinux/netport.c +++ b/security/selinux/netport.c @@ -137,9 +137,9 @@ static void sel_netport_insert(struct sel_netport *port) */ static int sel_netport_sid_slow(u8 protocol, u16 pnum, u32 *sid) { - int ret = -ENOMEM; + int ret; struct sel_netport *port; - struct sel_netport *new = NULL; + struct sel_netport *new; spin_lock_bh(&sel_netport_lock); port = sel_netport_find(protocol, pnum); @@ -148,25 +148,23 @@ static int sel_netport_sid_slow(u8 protocol, u16 pnum, u32 *sid) spin_unlock_bh(&sel_netport_lock); return 0; } - new = kzalloc(sizeof(*new), GFP_ATOMIC); - if (new == NULL) - goto out; + ret = security_port_sid(&selinux_state, protocol, pnum, sid); if (ret != 0) goto out; - - new->psec.port = pnum; - new->psec.protocol = protocol; - new->psec.sid = *sid; - sel_netport_insert(new); + new = kzalloc(sizeof(*new), GFP_ATOMIC); + if (new) { + new->psec.port = pnum; + new->psec.protocol = protocol; + new->psec.sid = *sid; + sel_netport_insert(new); + } out: spin_unlock_bh(&sel_netport_lock); - if (unlikely(ret)) { + if (unlikely(ret)) pr_warn("SELinux: failure in %s(), unable to determine network port label\n", __func__); - kfree(new); - } return ret; } diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index f8efaa9f647c..1260f5fb766e 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -177,6 +177,195 @@ static struct policydb_compat_info *policydb_lookup_compat(int version) } /* + * The following *_destroy functions are used to + * free any memory allocated for each kind of + * symbol data in the policy database. + */ + +static int perm_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static int common_destroy(void *key, void *datum, void *p) +{ + struct common_datum *comdatum; + + kfree(key); + if (datum) { + comdatum = datum; + hashtab_map(comdatum->permissions.table, perm_destroy, NULL); + hashtab_destroy(comdatum->permissions.table); + } + kfree(datum); + return 0; +} + +static void constraint_expr_destroy(struct constraint_expr *expr) +{ + if (expr) { + ebitmap_destroy(&expr->names); + if (expr->type_names) { + ebitmap_destroy(&expr->type_names->types); + ebitmap_destroy(&expr->type_names->negset); + kfree(expr->type_names); + } + kfree(expr); + } +} + +static int cls_destroy(void *key, void *datum, void *p) +{ + struct class_datum *cladatum; + struct constraint_node *constraint, *ctemp; + struct constraint_expr *e, *etmp; + + kfree(key); + if (datum) { + cladatum = datum; + hashtab_map(cladatum->permissions.table, perm_destroy, NULL); + hashtab_destroy(cladatum->permissions.table); + constraint = cladatum->constraints; + while (constraint) { + e = constraint->expr; + while (e) { + etmp = e; + e = e->next; + constraint_expr_destroy(etmp); + } + ctemp = constraint; + constraint = constraint->next; + kfree(ctemp); + } + + constraint = cladatum->validatetrans; + while (constraint) { + e = constraint->expr; + while (e) { + etmp = e; + e = e->next; + constraint_expr_destroy(etmp); + } + ctemp = constraint; + constraint = constraint->next; + kfree(ctemp); + } + kfree(cladatum->comkey); + } + kfree(datum); + return 0; +} + +static int role_destroy(void *key, void *datum, void *p) +{ + struct role_datum *role; + + kfree(key); + if (datum) { + role = datum; + ebitmap_destroy(&role->dominates); + ebitmap_destroy(&role->types); + } + kfree(datum); + return 0; +} + +static int type_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static int user_destroy(void *key, void *datum, void *p) +{ + struct user_datum *usrdatum; + + kfree(key); + if (datum) { + usrdatum = datum; + ebitmap_destroy(&usrdatum->roles); + ebitmap_destroy(&usrdatum->range.level[0].cat); + ebitmap_destroy(&usrdatum->range.level[1].cat); + ebitmap_destroy(&usrdatum->dfltlevel.cat); + } + kfree(datum); + return 0; +} + +static int sens_destroy(void *key, void *datum, void *p) +{ + struct level_datum *levdatum; + + kfree(key); + if (datum) { + levdatum = datum; + if (levdatum->level) + ebitmap_destroy(&levdatum->level->cat); + kfree(levdatum->level); + } + kfree(datum); + return 0; +} + +static int cat_destroy(void *key, void *datum, void *p) +{ + kfree(key); + kfree(datum); + return 0; +} + +static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) = +{ + common_destroy, + cls_destroy, + role_destroy, + type_destroy, + user_destroy, + cond_destroy_bool, + sens_destroy, + cat_destroy, +}; + +static int filenametr_destroy(void *key, void *datum, void *p) +{ + struct filename_trans *ft = key; + + kfree(ft->name); + kfree(key); + kfree(datum); + cond_resched(); + return 0; +} + +static int range_tr_destroy(void *key, void *datum, void *p) +{ + struct mls_range *rt = datum; + + kfree(key); + ebitmap_destroy(&rt->level[0].cat); + ebitmap_destroy(&rt->level[1].cat); + kfree(datum); + cond_resched(); + return 0; +} + +static void ocontext_destroy(struct ocontext *c, int i) +{ + if (!c) + return; + + context_destroy(&c->context[0]); + context_destroy(&c->context[1]); + if (i == OCON_ISID || i == OCON_FS || + i == OCON_NETIF || i == OCON_FSUSE) + kfree(c->u.name); + kfree(c); +} + +/* * Initialize the role table. */ static int roles_init(struct policydb *p) @@ -250,6 +439,7 @@ static int filenametr_cmp(struct hashtab *h, const void *k1, const void *k2) static u32 rangetr_hash(struct hashtab *h, const void *k) { const struct range_trans *key = k; + return (key->source_type + (key->target_type << 3) + (key->target_class << 5)) & (h->size - 1); } @@ -272,8 +462,6 @@ static int rangetr_cmp(struct hashtab *h, const void *k1, const void *k2) return v; } -static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap); - /* * Initialize a policy database structure. */ @@ -301,7 +489,8 @@ static int policydb_init(struct policydb *p) if (rc) goto out; - p->filename_trans = hashtab_create(filenametr_hash, filenametr_cmp, (1 << 10)); + p->filename_trans = hashtab_create(filenametr_hash, filenametr_cmp, + (1 << 10)); if (!p->filename_trans) { rc = -ENOMEM; goto out; @@ -399,7 +588,7 @@ static int type_index(void *key, void *datum, void *datap) || typdatum->bounds > p->p_types.nprim) return -EINVAL; p->sym_val_to_name[SYM_TYPES][typdatum->value - 1] = key; - p->type_val_to_struct_array[typdatum->value - 1] = typdatum; + p->type_val_to_struct[typdatum->value - 1] = typdatum; } return 0; @@ -477,9 +666,9 @@ static void hash_eval(struct hashtab *h, const char *hash_name) struct hashtab_info info; hashtab_stat(h, &info); - pr_debug("SELinux: %s: %d entries and %d/%d buckets used, " - "longest chain length %d\n", hash_name, h->nel, - info.slots_used, h->size, info.max_chain_len); + pr_debug("SELinux: %s: %d entries and %d/%d buckets used, longest chain length %d\n", + hash_name, h->nel, info.slots_used, h->size, + info.max_chain_len); } static void symtab_hash_eval(struct symtab *s) @@ -541,10 +730,10 @@ static int policydb_index(struct policydb *p) if (!p->user_val_to_struct) return -ENOMEM; - p->type_val_to_struct_array = kvcalloc(p->p_types.nprim, - sizeof(*p->type_val_to_struct_array), - GFP_KERNEL); - if (!p->type_val_to_struct_array) + p->type_val_to_struct = kvcalloc(p->p_types.nprim, + sizeof(*p->type_val_to_struct), + GFP_KERNEL); + if (!p->type_val_to_struct) return -ENOMEM; rc = cond_init_bool_indexes(p); @@ -568,193 +757,6 @@ out: } /* - * The following *_destroy functions are used to - * free any memory allocated for each kind of - * symbol data in the policy database. - */ - -static int perm_destroy(void *key, void *datum, void *p) -{ - kfree(key); - kfree(datum); - return 0; -} - -static int common_destroy(void *key, void *datum, void *p) -{ - struct common_datum *comdatum; - - kfree(key); - if (datum) { - comdatum = datum; - hashtab_map(comdatum->permissions.table, perm_destroy, NULL); - hashtab_destroy(comdatum->permissions.table); - } - kfree(datum); - return 0; -} - -static void constraint_expr_destroy(struct constraint_expr *expr) -{ - if (expr) { - ebitmap_destroy(&expr->names); - if (expr->type_names) { - ebitmap_destroy(&expr->type_names->types); - ebitmap_destroy(&expr->type_names->negset); - kfree(expr->type_names); - } - kfree(expr); - } -} - -static int cls_destroy(void *key, void *datum, void *p) -{ - struct class_datum *cladatum; - struct constraint_node *constraint, *ctemp; - struct constraint_expr *e, *etmp; - - kfree(key); - if (datum) { - cladatum = datum; - hashtab_map(cladatum->permissions.table, perm_destroy, NULL); - hashtab_destroy(cladatum->permissions.table); - constraint = cladatum->constraints; - while (constraint) { - e = constraint->expr; - while (e) { - etmp = e; - e = e->next; - constraint_expr_destroy(etmp); - } - ctemp = constraint; - constraint = constraint->next; - kfree(ctemp); - } - - constraint = cladatum->validatetrans; - while (constraint) { - e = constraint->expr; - while (e) { - etmp = e; - e = e->next; - constraint_expr_destroy(etmp); - } - ctemp = constraint; - constraint = constraint->next; - kfree(ctemp); - } - kfree(cladatum->comkey); - } - kfree(datum); - return 0; -} - -static int role_destroy(void *key, void *datum, void *p) -{ - struct role_datum *role; - - kfree(key); - if (datum) { - role = datum; - ebitmap_destroy(&role->dominates); - ebitmap_destroy(&role->types); - } - kfree(datum); - return 0; -} - -static int type_destroy(void *key, void *datum, void *p) -{ - kfree(key); - kfree(datum); - return 0; -} - -static int user_destroy(void *key, void *datum, void *p) -{ - struct user_datum *usrdatum; - - kfree(key); - if (datum) { - usrdatum = datum; - ebitmap_destroy(&usrdatum->roles); - ebitmap_destroy(&usrdatum->range.level[0].cat); - ebitmap_destroy(&usrdatum->range.level[1].cat); - ebitmap_destroy(&usrdatum->dfltlevel.cat); - } - kfree(datum); - return 0; -} - -static int sens_destroy(void *key, void *datum, void *p) -{ - struct level_datum *levdatum; - - kfree(key); - if (datum) { - levdatum = datum; - if (levdatum->level) - ebitmap_destroy(&levdatum->level->cat); - kfree(levdatum->level); - } - kfree(datum); - return 0; -} - -static int cat_destroy(void *key, void *datum, void *p) -{ - kfree(key); - kfree(datum); - return 0; -} - -static int (*destroy_f[SYM_NUM]) (void *key, void *datum, void *datap) = -{ - common_destroy, - cls_destroy, - role_destroy, - type_destroy, - user_destroy, - cond_destroy_bool, - sens_destroy, - cat_destroy, -}; - -static int filenametr_destroy(void *key, void *datum, void *p) -{ - struct filename_trans *ft = key; - kfree(ft->name); - kfree(key); - kfree(datum); - cond_resched(); - return 0; -} - -static int range_tr_destroy(void *key, void *datum, void *p) -{ - struct mls_range *rt = datum; - kfree(key); - ebitmap_destroy(&rt->level[0].cat); - ebitmap_destroy(&rt->level[1].cat); - kfree(datum); - cond_resched(); - return 0; -} - -static void ocontext_destroy(struct ocontext *c, int i) -{ - if (!c) - return; - - context_destroy(&c->context[0]); - context_destroy(&c->context[1]); - if (i == OCON_ISID || i == OCON_FS || - i == OCON_NETIF || i == OCON_FSUSE) - kfree(c->u.name); - kfree(c); -} - -/* * Free any memory allocated by a policy database structure. */ void policydb_destroy(struct policydb *p) @@ -777,7 +779,7 @@ void policydb_destroy(struct policydb *p) kfree(p->class_val_to_struct); kfree(p->role_val_to_struct); kfree(p->user_val_to_struct); - kvfree(p->type_val_to_struct_array); + kvfree(p->type_val_to_struct); avtab_destroy(&p->te_avtab); @@ -1722,7 +1724,7 @@ static int type_bounds_sanity_check(void *key, void *datum, void *datap) return -EINVAL; } - upper = p->type_val_to_struct_array[upper->bounds - 1]; + upper = p->type_val_to_struct[upper->bounds - 1]; BUG_ON(!upper); if (upper->attribute) { diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h index fcc6366b447f..162d0e79b85b 100644 --- a/security/selinux/ss/policydb.h +++ b/security/selinux/ss/policydb.h @@ -253,7 +253,7 @@ struct policydb { struct class_datum **class_val_to_struct; struct role_datum **role_val_to_struct; struct user_datum **user_val_to_struct; - struct type_datum **type_val_to_struct_array; + struct type_datum **type_val_to_struct; /* type enforcement access vectors and transitions */ struct avtab te_avtab; diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index d61563a3695e..3a29e7c24ba9 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -542,13 +542,13 @@ static void type_attribute_bounds_av(struct policydb *policydb, struct type_datum *target; u32 masked = 0; - source = policydb->type_val_to_struct_array[scontext->type - 1]; + source = policydb->type_val_to_struct[scontext->type - 1]; BUG_ON(!source); if (!source->bounds) return; - target = policydb->type_val_to_struct_array[tcontext->type - 1]; + target = policydb->type_val_to_struct[tcontext->type - 1]; BUG_ON(!target); memset(&lo_avd, 0, sizeof(lo_avd)); @@ -891,7 +891,7 @@ int security_bounded_transition(struct selinux_state *state, index = new_context->type; while (true) { - type = policydb->type_val_to_struct_array[index - 1]; + type = policydb->type_val_to_struct[index - 1]; BUG_ON(!type); /* not bounded anymore */ diff --git a/security/selinux/ss/sidtab.c b/security/selinux/ss/sidtab.c index 1f0a6eaa2d6a..7d49994e8d5f 100644 --- a/security/selinux/ss/sidtab.c +++ b/security/selinux/ss/sidtab.c @@ -12,7 +12,7 @@ #include <linux/slab.h> #include <linux/sched.h> #include <linux/spinlock.h> -#include <linux/atomic.h> +#include <asm/barrier.h> #include "flask.h" #include "security.h" #include "sidtab.h" @@ -23,14 +23,14 @@ int sidtab_init(struct sidtab *s) memset(s->roots, 0, sizeof(s->roots)); + /* max count is SIDTAB_MAX so valid index is always < SIDTAB_MAX */ for (i = 0; i < SIDTAB_RCACHE_SIZE; i++) - atomic_set(&s->rcache[i], -1); + s->rcache[i] = SIDTAB_MAX; for (i = 0; i < SECINITSID_NUM; i++) s->isids[i].set = 0; - atomic_set(&s->count, 0); - + s->count = 0; s->convert = NULL; spin_lock_init(&s->lock); @@ -130,14 +130,12 @@ static struct context *sidtab_do_lookup(struct sidtab *s, u32 index, int alloc) static struct context *sidtab_lookup(struct sidtab *s, u32 index) { - u32 count = (u32)atomic_read(&s->count); + /* read entries only after reading count */ + u32 count = smp_load_acquire(&s->count); if (index >= count) return NULL; - /* read entries after reading count */ - smp_rmb(); - return sidtab_do_lookup(s, index, 0); } @@ -210,10 +208,10 @@ static int sidtab_find_context(union sidtab_entry_inner entry, static void sidtab_rcache_update(struct sidtab *s, u32 index, u32 pos) { while (pos > 0) { - atomic_set(&s->rcache[pos], atomic_read(&s->rcache[pos - 1])); + WRITE_ONCE(s->rcache[pos], READ_ONCE(s->rcache[pos - 1])); --pos; } - atomic_set(&s->rcache[0], (int)index); + WRITE_ONCE(s->rcache[0], index); } static void sidtab_rcache_push(struct sidtab *s, u32 index) @@ -227,14 +225,14 @@ static int sidtab_rcache_search(struct sidtab *s, struct context *context, u32 i; for (i = 0; i < SIDTAB_RCACHE_SIZE; i++) { - int v = atomic_read(&s->rcache[i]); + u32 v = READ_ONCE(s->rcache[i]); - if (v < 0) + if (v >= SIDTAB_MAX) continue; - if (context_cmp(sidtab_do_lookup(s, (u32)v, 0), context)) { - sidtab_rcache_update(s, (u32)v, i); - *index = (u32)v; + if (context_cmp(sidtab_do_lookup(s, v, 0), context)) { + sidtab_rcache_update(s, v, i); + *index = v; return 0; } } @@ -245,8 +243,7 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context, u32 *index) { unsigned long flags; - u32 count = (u32)atomic_read(&s->count); - u32 count_locked, level, pos; + u32 count, count_locked, level, pos; struct sidtab_convert_params *convert; struct context *dst, *dst_convert; int rc; @@ -255,11 +252,10 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context, if (rc == 0) return 0; + /* read entries only after reading count */ + count = smp_load_acquire(&s->count); level = sidtab_level_from_count(count); - /* read entries after reading count */ - smp_rmb(); - pos = 0; rc = sidtab_find_context(s->roots[level], &pos, count, level, context, index); @@ -272,7 +268,7 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context, spin_lock_irqsave(&s->lock, flags); convert = s->convert; - count_locked = (u32)atomic_read(&s->count); + count_locked = s->count; level = sidtab_level_from_count(count_locked); /* if count has changed before we acquired the lock, then catch up */ @@ -320,7 +316,7 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context, } /* at this point we know the insert won't fail */ - atomic_set(&convert->target->count, count + 1); + convert->target->count = count + 1; } if (context->len) @@ -331,9 +327,7 @@ static int sidtab_reverse_lookup(struct sidtab *s, struct context *context, *index = count; /* write entries before writing new count */ - smp_wmb(); - - atomic_set(&s->count, count + 1); + smp_store_release(&s->count, count + 1); rc = 0; out_unlock: @@ -423,7 +417,7 @@ int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params) return -EBUSY; } - count = (u32)atomic_read(&s->count); + count = s->count; level = sidtab_level_from_count(count); /* allocate last leaf in the new sidtab (to avoid race with @@ -436,7 +430,7 @@ int sidtab_convert(struct sidtab *s, struct sidtab_convert_params *params) } /* set count in case no new entries are added during conversion */ - atomic_set(¶ms->target->count, count); + params->target->count = count; /* enable live convert of new entries */ s->convert = params; diff --git a/security/selinux/ss/sidtab.h b/security/selinux/ss/sidtab.h index bbd5c0d1f3bd..1f4763141aa1 100644 --- a/security/selinux/ss/sidtab.h +++ b/security/selinux/ss/sidtab.h @@ -40,8 +40,8 @@ union sidtab_entry_inner { #define SIDTAB_LEAF_ENTRIES \ (SIDTAB_NODE_ALLOC_SIZE / sizeof(struct sidtab_entry_leaf)) -#define SIDTAB_MAX_BITS 31 /* limited to INT_MAX due to atomic_t range */ -#define SIDTAB_MAX (((u32)1 << SIDTAB_MAX_BITS) - 1) +#define SIDTAB_MAX_BITS 32 +#define SIDTAB_MAX U32_MAX /* ensure enough tree levels for SIDTAB_MAX entries */ #define SIDTAB_MAX_LEVEL \ DIV_ROUND_UP(SIDTAB_MAX_BITS - size_to_shift(SIDTAB_LEAF_ENTRIES), \ @@ -69,13 +69,22 @@ struct sidtab_convert_params { #define SIDTAB_RCACHE_SIZE 3 struct sidtab { + /* + * lock-free read access only for as many items as a prior read of + * 'count' + */ union sidtab_entry_inner roots[SIDTAB_MAX_LEVEL + 1]; - atomic_t count; + /* + * access atomically via {READ|WRITE}_ONCE(); only increment under + * spinlock + */ + u32 count; + /* access only under spinlock */ struct sidtab_convert_params *convert; spinlock_t lock; - /* reverse lookup cache */ - atomic_t rcache[SIDTAB_RCACHE_SIZE]; + /* reverse lookup cache - access atomically via {READ|WRITE}_ONCE() */ + u32 rcache[SIDTAB_RCACHE_SIZE]; /* index == SID - 1 (no entry for SECSID_NULL) */ struct sidtab_isid_entry isids[SECINITSID_NUM]; |