X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Fauditfilter.c;h=a70604047f3c9061e81622a3b399b085fe5ac815;hb=88ec22d3edb72b261f8628226cd543589a6d5e1b;hp=85a7862143a12412ea3bd4382e1c367b025bf5eb;hpb=3dc7e3153eddfcf7ba8b50628775ba516e5f759f;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 85a7862..a706040 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -22,13 +22,28 @@ #include #include #include +#include +#include +#include #include -#include +#include +#include #include "audit.h" -/* There are three lists of rules -- one to search at task creation - * time, one to search at syscall entry time, and another to search at - * syscall exit time. */ +/* + * Locking model: + * + * audit_filter_mutex: + * Synchronizes writes and blocking reads of audit's filterlist + * data. Rcu is used to traverse the filterlist and access + * contents of structs audit_entry, audit_watch and opaque + * LSM rules during filtering. If modified, these structures + * must be copied and replace their counterparts in the filterlist. + * An audit_parent struct is not accessed during filtering, so may + * be written directly provided audit_filter_mutex is held. + */ + +/* Audit filter lists, defined in */ struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { LIST_HEAD_INIT(audit_filter_list[0]), LIST_HEAD_INIT(audit_filter_list[1]), @@ -40,21 +55,36 @@ struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { #error Fix audit_filter_list initialiser #endif }; +static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = { + LIST_HEAD_INIT(audit_rules_list[0]), + LIST_HEAD_INIT(audit_rules_list[1]), + LIST_HEAD_INIT(audit_rules_list[2]), + LIST_HEAD_INIT(audit_rules_list[3]), + LIST_HEAD_INIT(audit_rules_list[4]), + LIST_HEAD_INIT(audit_rules_list[5]), +}; + +DEFINE_MUTEX(audit_filter_mutex); static inline void audit_free_rule(struct audit_entry *e) { int i; - if (e->rule.fields) - for (i = 0; i < e->rule.field_count; i++) { - struct audit_field *f = &e->rule.fields[i]; - kfree(f->se_str); - selinux_audit_rule_free(f->se_rule); + struct audit_krule *erule = &e->rule; + /* some rules don't have associated watches */ + if (erule->watch) + audit_put_watch(erule->watch); + if (erule->fields) + for (i = 0; i < erule->field_count; i++) { + struct audit_field *f = &erule->fields[i]; + kfree(f->lsm_str); + security_audit_rule_free(f->lsm_rule); } - kfree(e->rule.fields); + kfree(erule->fields); + kfree(erule->filterkey); kfree(e); } -static inline void audit_free_rule_rcu(struct rcu_head *head) +void audit_free_rule_rcu(struct rcu_head *head) { struct audit_entry *e = container_of(head, struct audit_entry, rcu); audit_free_rule(e); @@ -82,7 +112,7 @@ static inline struct audit_entry *audit_init_entry(u32 field_count) /* Unpack a filter field's string representation from user-space * buffer. */ -static char *audit_unpack_string(void **bufp, size_t *remain, size_t len) +char *audit_unpack_string(void **bufp, size_t *remain, size_t len) { char *str; @@ -107,6 +137,90 @@ static char *audit_unpack_string(void **bufp, size_t *remain, size_t len) return str; } +/* Translate an inode field to kernel respresentation. */ +static inline int audit_to_inode(struct audit_krule *krule, + struct audit_field *f) +{ + if (krule->listnr != AUDIT_FILTER_EXIT || + krule->watch || krule->inode_f || krule->tree || + (f->op != Audit_equal && f->op != Audit_not_equal)) + return -EINVAL; + + krule->inode_f = f; + return 0; +} + +static __u32 *classes[AUDIT_SYSCALL_CLASSES]; + +int __init audit_register_class(int class, unsigned *list) +{ + __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL); + if (!p) + return -ENOMEM; + while (*list != ~0U) { + unsigned n = *list++; + if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) { + kfree(p); + return -EINVAL; + } + p[AUDIT_WORD(n)] |= AUDIT_BIT(n); + } + if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) { + kfree(p); + return -EINVAL; + } + classes[class] = p; + return 0; +} + +int audit_match_class(int class, unsigned syscall) +{ + if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32)) + return 0; + if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class])) + return 0; + return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall); +} + +#ifdef CONFIG_AUDITSYSCALL +static inline int audit_match_class_bits(int class, u32 *mask) +{ + int i; + + if (classes[class]) { + for (i = 0; i < AUDIT_BITMASK_SIZE; i++) + if (mask[i] & classes[class][i]) + return 0; + } + return 1; +} + +static int audit_match_signal(struct audit_entry *entry) +{ + struct audit_field *arch = entry->rule.arch_f; + + if (!arch) { + /* When arch is unspecified, we must check both masks on biarch + * as syscall number alone is ambiguous. */ + return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, + entry->rule.mask) && + audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, + entry->rule.mask)); + } + + switch(audit_classify_arch(arch->val)) { + case 0: /* native */ + return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, + entry->rule.mask)); + case 1: /* 32bit on biarch */ + return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, + entry->rule.mask)); + default: + return 1; + } +} +#endif + /* Common user-space to kernel rule translation. */ static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) { @@ -128,8 +242,11 @@ static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) #endif ; } - if (rule->action != AUDIT_NEVER && rule->action != AUDIT_POSSIBLE && - rule->action != AUDIT_ALWAYS) + if (unlikely(rule->action == AUDIT_POSSIBLE)) { + printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n"); + goto exit_err; + } + if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) goto exit_err; if (rule->field_count > AUDIT_MAX_FIELDS) goto exit_err; @@ -147,12 +264,49 @@ static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) for (i = 0; i < AUDIT_BITMASK_SIZE; i++) entry->rule.mask[i] = rule->mask[i]; + for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) { + int bit = AUDIT_BITMASK_SIZE * 32 - i - 1; + __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)]; + __u32 *class; + + if (!(*p & AUDIT_BIT(bit))) + continue; + *p &= ~AUDIT_BIT(bit); + class = classes[i]; + if (class) { + int j; + for (j = 0; j < AUDIT_BITMASK_SIZE; j++) + entry->rule.mask[j] |= class[j]; + } + } + return entry; exit_err: return ERR_PTR(err); } +static u32 audit_ops[] = +{ + [Audit_equal] = AUDIT_EQUAL, + [Audit_not_equal] = AUDIT_NOT_EQUAL, + [Audit_bitmask] = AUDIT_BIT_MASK, + [Audit_bittest] = AUDIT_BIT_TEST, + [Audit_lt] = AUDIT_LESS_THAN, + [Audit_gt] = AUDIT_GREATER_THAN, + [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL, + [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL, +}; + +static u32 audit_to_op(u32 op) +{ + u32 n; + for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++) + ; + return n; +} + + /* Translate struct audit_rule to kernel's rule respresentation. * Exists for backward compatibility with userspace. */ static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) @@ -167,35 +321,82 @@ static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) for (i = 0; i < rule->field_count; i++) { struct audit_field *f = &entry->rule.fields[i]; + u32 n; + + n = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); + + /* Support for legacy operators where + * AUDIT_NEGATE bit signifies != and otherwise assumes == */ + if (n & AUDIT_NEGATE) + f->op = Audit_not_equal; + else if (!n) + f->op = Audit_equal; + else + f->op = audit_to_op(n); + + entry->rule.vers_ops = (n & AUDIT_OPERATORS) ? 2 : 1; - f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); f->val = rule->values[i]; - if (f->type & AUDIT_UNUSED_BITS || - f->type == AUDIT_SE_USER || - f->type == AUDIT_SE_ROLE || - f->type == AUDIT_SE_TYPE || - f->type == AUDIT_SE_SEN || - f->type == AUDIT_SE_CLR) { - err = -EINVAL; + err = -EINVAL; + if (f->op == Audit_bad) goto exit_free; - } - - entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1; - /* Support for legacy operators where - * AUDIT_NEGATE bit signifies != and otherwise assumes == */ - if (f->op & AUDIT_NEGATE) - f->op = AUDIT_NOT_EQUAL; - else if (!f->op) - f->op = AUDIT_EQUAL; - else if (f->op == AUDIT_OPERATORS) { - err = -EINVAL; + switch(f->type) { + default: goto exit_free; + case AUDIT_PID: + case AUDIT_UID: + case AUDIT_EUID: + case AUDIT_SUID: + case AUDIT_FSUID: + case AUDIT_GID: + case AUDIT_EGID: + case AUDIT_SGID: + case AUDIT_FSGID: + case AUDIT_LOGINUID: + case AUDIT_PERS: + case AUDIT_MSGTYPE: + case AUDIT_PPID: + case AUDIT_DEVMAJOR: + case AUDIT_DEVMINOR: + case AUDIT_EXIT: + case AUDIT_SUCCESS: + /* bit ops are only useful on syscall args */ + if (f->op == Audit_bitmask || f->op == Audit_bittest) + goto exit_free; + break; + case AUDIT_ARG0: + case AUDIT_ARG1: + case AUDIT_ARG2: + case AUDIT_ARG3: + break; + /* arch is only allowed to be = or != */ + case AUDIT_ARCH: + if (f->op != Audit_not_equal && f->op != Audit_equal) + goto exit_free; + entry->rule.arch_f = f; + break; + case AUDIT_PERM: + if (f->val & ~15) + goto exit_free; + break; + case AUDIT_FILETYPE: + if ((f->val & ~S_IFMT) > S_IFMT) + goto exit_free; + break; + case AUDIT_INODE: + err = audit_to_inode(&entry->rule, f); + if (err) + goto exit_free; + break; } } + if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) + entry->rule.inode_f = NULL; + exit_nofree: return entry; @@ -225,32 +426,62 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, struct audit_field *f = &entry->rule.fields[i]; err = -EINVAL; - if (!(data->fieldflags[i] & AUDIT_OPERATORS) || - data->fieldflags[i] & ~AUDIT_OPERATORS) + + f->op = audit_to_op(data->fieldflags[i]); + if (f->op == Audit_bad) goto exit_free; - f->op = data->fieldflags[i] & AUDIT_OPERATORS; f->type = data->fields[i]; f->val = data->values[i]; - f->se_str = NULL; - f->se_rule = NULL; + f->lsm_str = NULL; + f->lsm_rule = NULL; switch(f->type) { - case AUDIT_SE_USER: - case AUDIT_SE_ROLE: - case AUDIT_SE_TYPE: - case AUDIT_SE_SEN: - case AUDIT_SE_CLR: + case AUDIT_PID: + case AUDIT_UID: + case AUDIT_EUID: + case AUDIT_SUID: + case AUDIT_FSUID: + case AUDIT_GID: + case AUDIT_EGID: + case AUDIT_SGID: + case AUDIT_FSGID: + case AUDIT_LOGINUID: + case AUDIT_PERS: + case AUDIT_MSGTYPE: + case AUDIT_PPID: + case AUDIT_DEVMAJOR: + case AUDIT_DEVMINOR: + case AUDIT_EXIT: + case AUDIT_SUCCESS: + case AUDIT_ARG0: + case AUDIT_ARG1: + case AUDIT_ARG2: + case AUDIT_ARG3: + break; + case AUDIT_ARCH: + entry->rule.arch_f = f; + break; + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: str = audit_unpack_string(&bufp, &remain, f->val); if (IS_ERR(str)) goto exit_free; entry->rule.buflen += f->val; - err = selinux_audit_rule_init(f->type, f->op, str, - &f->se_rule); + err = security_audit_rule_init(f->type, f->op, str, + (void **)&f->lsm_rule); /* Keep currently invalid fields around in case they * become valid after a policy reload. */ if (err == -EINVAL) { - printk(KERN_WARNING "audit rule for selinux " + printk(KERN_WARNING "audit rule for LSM " "\'%s\' is invalid\n", str); err = 0; } @@ -258,11 +489,62 @@ static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, kfree(str); goto exit_free; } else - f->se_str = str; + f->lsm_str = str; break; + case AUDIT_WATCH: + str = audit_unpack_string(&bufp, &remain, f->val); + if (IS_ERR(str)) + goto exit_free; + entry->rule.buflen += f->val; + + err = audit_to_watch(&entry->rule, str, f->val, f->op); + if (err) { + kfree(str); + goto exit_free; + } + break; + case AUDIT_DIR: + str = audit_unpack_string(&bufp, &remain, f->val); + if (IS_ERR(str)) + goto exit_free; + entry->rule.buflen += f->val; + + err = audit_make_tree(&entry->rule, str, f->op); + kfree(str); + if (err) + goto exit_free; + break; + case AUDIT_INODE: + err = audit_to_inode(&entry->rule, f); + if (err) + goto exit_free; + break; + case AUDIT_FILTERKEY: + err = -EINVAL; + if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN) + goto exit_free; + str = audit_unpack_string(&bufp, &remain, f->val); + if (IS_ERR(str)) + goto exit_free; + entry->rule.buflen += f->val; + entry->rule.filterkey = str; + break; + case AUDIT_PERM: + if (f->val & ~15) + goto exit_free; + break; + case AUDIT_FILETYPE: + if ((f->val & ~S_IFMT) > S_IFMT) + goto exit_free; + break; + default: + goto exit_free; } } + if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) + entry->rule.inode_f = NULL; + exit_nofree: return entry; @@ -272,7 +554,7 @@ exit_free: } /* Pack a filter field's string representation into data block. */ -static inline size_t audit_pack_string(void **bufp, char *str) +static inline size_t audit_pack_string(void **bufp, const char *str) { size_t len = strlen(str); @@ -289,10 +571,9 @@ static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) struct audit_rule *rule; int i; - rule = kmalloc(sizeof(*rule), GFP_KERNEL); + rule = kzalloc(sizeof(*rule), GFP_KERNEL); if (unlikely(!rule)) - return ERR_PTR(-ENOMEM); - memset(rule, 0, sizeof(*rule)); + return NULL; rule->flags = krule->flags | krule->listnr; rule->action = krule->action; @@ -302,10 +583,10 @@ static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) rule->fields[i] = krule->fields[i].type; if (krule->vers_ops == 1) { - if (krule->fields[i].op & AUDIT_NOT_EQUAL) + if (krule->fields[i].op == Audit_not_equal) rule->fields[i] |= AUDIT_NEGATE; } else { - rule->fields[i] |= krule->fields[i].op; + rule->fields[i] |= audit_ops[krule->fields[i].op]; } } for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; @@ -322,7 +603,7 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); if (unlikely(!data)) - return ERR_PTR(-ENOMEM); + return NULL; memset(data, 0, sizeof(*data)); data->flags = krule->flags | krule->listnr; @@ -333,15 +614,34 @@ static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) struct audit_field *f = &krule->fields[i]; data->fields[i] = f->type; - data->fieldflags[i] = f->op; + data->fieldflags[i] = audit_ops[f->op]; switch(f->type) { - case AUDIT_SE_USER: - case AUDIT_SE_ROLE: - case AUDIT_SE_TYPE: - case AUDIT_SE_SEN: - case AUDIT_SE_CLR: + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + data->buflen += data->values[i] = + audit_pack_string(&bufp, f->lsm_str); + break; + case AUDIT_WATCH: + data->buflen += data->values[i] = + audit_pack_string(&bufp, + audit_watch_path(krule->watch)); + break; + case AUDIT_DIR: + data->buflen += data->values[i] = + audit_pack_string(&bufp, + audit_tree_path(krule->tree)); + break; + case AUDIT_FILTERKEY: data->buflen += data->values[i] = - audit_pack_string(&bufp, f->se_str); + audit_pack_string(&bufp, krule->filterkey); break; default: data->values[i] = f->val; @@ -370,12 +670,32 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) return 1; switch(a->fields[i].type) { - case AUDIT_SE_USER: - case AUDIT_SE_ROLE: - case AUDIT_SE_TYPE: - case AUDIT_SE_SEN: - case AUDIT_SE_CLR: - if (strcmp(a->fields[i].se_str, b->fields[i].se_str)) + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str)) + return 1; + break; + case AUDIT_WATCH: + if (strcmp(audit_watch_path(a->watch), + audit_watch_path(b->watch))) + return 1; + break; + case AUDIT_DIR: + if (strcmp(audit_tree_path(a->tree), + audit_tree_path(b->tree))) + return 1; + break; + case AUDIT_FILTERKEY: + /* both filterkeys exist based on above type compare */ + if (strcmp(a->filterkey, b->filterkey)) return 1; break; default: @@ -391,28 +711,28 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) return 0; } -/* Duplicate selinux field information. The se_rule is opaque, so must be +/* Duplicate LSM field information. The lsm_rule is opaque, so must be * re-initialized. */ -static inline int audit_dupe_selinux_field(struct audit_field *df, +static inline int audit_dupe_lsm_field(struct audit_field *df, struct audit_field *sf) { int ret = 0; - char *se_str; + char *lsm_str; - /* our own copy of se_str */ - se_str = kstrdup(sf->se_str, GFP_KERNEL); - if (unlikely(IS_ERR(se_str))) - return -ENOMEM; - df->se_str = se_str; + /* our own copy of lsm_str */ + lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL); + if (unlikely(!lsm_str)) + return -ENOMEM; + df->lsm_str = lsm_str; - /* our own (refreshed) copy of se_rule */ - ret = selinux_audit_rule_init(df->type, df->op, df->se_str, - &df->se_rule); + /* our own (refreshed) copy of lsm_rule */ + ret = security_audit_rule_init(df->type, df->op, df->lsm_str, + (void **)&df->lsm_rule); /* Keep currently invalid fields around in case they * become valid after a policy reload. */ if (ret == -EINVAL) { - printk(KERN_WARNING "audit rule for selinux \'%s\' is " - "invalid\n", df->se_str); + printk(KERN_WARNING "audit rule for LSM \'%s\' is " + "invalid\n", df->lsm_str); ret = 0; } @@ -420,14 +740,18 @@ static inline int audit_dupe_selinux_field(struct audit_field *df, } /* Duplicate an audit rule. This will be a deep copy with the exception - * of the watch - that pointer is carried over. The selinux specific fields + * of the watch - that pointer is carried over. The LSM specific fields * will be updated in the copy. The point is to be able to replace the old - * rule with the new rule in the filterlist, then free the old rule. */ -static struct audit_entry *audit_dupe_rule(struct audit_krule *old) + * rule with the new rule in the filterlist, then free the old rule. + * The rlist element is undefined; list manipulations are handled apart from + * the initial copy. */ +struct audit_entry *audit_dupe_rule(struct audit_krule *old, + struct audit_watch *watch) { u32 fcount = old->field_count; struct audit_entry *entry; struct audit_krule *new; + char *fk; int i, err = 0; entry = audit_init_entry(fcount); @@ -441,21 +765,44 @@ static struct audit_entry *audit_dupe_rule(struct audit_krule *old) new->action = old->action; for (i = 0; i < AUDIT_BITMASK_SIZE; i++) new->mask[i] = old->mask[i]; + new->prio = old->prio; new->buflen = old->buflen; + new->inode_f = old->inode_f; + new->watch = NULL; new->field_count = old->field_count; + /* + * note that we are OK with not refcounting here; audit_match_tree() + * never dereferences tree and we can't get false positives there + * since we'd have to have rule gone from the list *and* removed + * before the chunks found by lookup had been allocated, i.e. before + * the beginning of list scan. + */ + new->tree = old->tree; memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); - /* deep copy this information, updating the se_rule fields, because + /* deep copy this information, updating the lsm_rule fields, because * the originals will all be freed when the old rule is freed. */ for (i = 0; i < fcount; i++) { switch (new->fields[i].type) { - case AUDIT_SE_USER: - case AUDIT_SE_ROLE: - case AUDIT_SE_TYPE: - case AUDIT_SE_SEN: - case AUDIT_SE_CLR: - err = audit_dupe_selinux_field(&new->fields[i], + case AUDIT_SUBJ_USER: + case AUDIT_SUBJ_ROLE: + case AUDIT_SUBJ_TYPE: + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + err = audit_dupe_lsm_field(&new->fields[i], &old->fields[i]); + break; + case AUDIT_FILTERKEY: + fk = kstrdup(old->filterkey, GFP_KERNEL); + if (unlikely(!fk)) + err = -ENOMEM; + else + new->filterkey = fk; } if (err) { audit_free_rule(entry); @@ -463,118 +810,280 @@ static struct audit_entry *audit_dupe_rule(struct audit_krule *old) } } + if (watch) { + audit_get_watch(watch); + new->watch = watch; + } + return entry; } -/* Add rule to given filterlist if not a duplicate. Protected by - * audit_netlink_mutex. */ -static inline int audit_add_rule(struct audit_entry *entry, - struct list_head *list) +/* Find an existing audit rule. + * Caller must hold audit_filter_mutex to prevent stale rule data. */ +static struct audit_entry *audit_find_rule(struct audit_entry *entry, + struct list_head **p) +{ + struct audit_entry *e, *found = NULL; + struct list_head *list; + int h; + + if (entry->rule.inode_f) { + h = audit_hash_ino(entry->rule.inode_f->val); + *p = list = &audit_inode_hash[h]; + } else if (entry->rule.watch) { + /* we don't know the inode number, so must walk entire hash */ + for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { + list = &audit_inode_hash[h]; + list_for_each_entry(e, list, list) + if (!audit_compare_rule(&entry->rule, &e->rule)) { + found = e; + goto out; + } + } + goto out; + } else { + *p = list = &audit_filter_list[entry->rule.listnr]; + } + + list_for_each_entry(e, list, list) + if (!audit_compare_rule(&entry->rule, &e->rule)) { + found = e; + goto out; + } + +out: + return found; +} + +static u64 prio_low = ~0ULL/2; +static u64 prio_high = ~0ULL/2 - 1; + +/* Add rule to given filterlist if not a duplicate. */ +static inline int audit_add_rule(struct audit_entry *entry) { struct audit_entry *e; + struct audit_watch *watch = entry->rule.watch; + struct audit_tree *tree = entry->rule.tree; + struct list_head *list; + int h, err; +#ifdef CONFIG_AUDITSYSCALL + int dont_count = 0; + + /* If either of these, don't count towards total */ + if (entry->rule.listnr == AUDIT_FILTER_USER || + entry->rule.listnr == AUDIT_FILTER_TYPE) + dont_count = 1; +#endif - /* Do not use the _rcu iterator here, since this is the only - * addition routine. */ - list_for_each_entry(e, list, list) { - if (!audit_compare_rule(&entry->rule, &e->rule)) - return -EEXIST; + mutex_lock(&audit_filter_mutex); + e = audit_find_rule(entry, &list); + if (e) { + mutex_unlock(&audit_filter_mutex); + err = -EEXIST; + /* normally audit_add_tree_rule() will free it on failure */ + if (tree) + audit_put_tree(tree); + goto error; + } + + if (watch) { + /* audit_filter_mutex is dropped and re-taken during this call */ + err = audit_add_watch(&entry->rule); + if (err) { + mutex_unlock(&audit_filter_mutex); + goto error; + } + /* entry->rule.watch may have changed during audit_add_watch() */ + watch = entry->rule.watch; + h = audit_hash_ino((u32)audit_watch_inode(watch)); + list = &audit_inode_hash[h]; + } + if (tree) { + err = audit_add_tree_rule(&entry->rule); + if (err) { + mutex_unlock(&audit_filter_mutex); + goto error; + } + } + + entry->rule.prio = ~0ULL; + if (entry->rule.listnr == AUDIT_FILTER_EXIT) { + if (entry->rule.flags & AUDIT_FILTER_PREPEND) + entry->rule.prio = ++prio_high; + else + entry->rule.prio = --prio_low; } if (entry->rule.flags & AUDIT_FILTER_PREPEND) { + list_add(&entry->rule.list, + &audit_rules_list[entry->rule.listnr]); list_add_rcu(&entry->list, list); + entry->rule.flags &= ~AUDIT_FILTER_PREPEND; } else { + list_add_tail(&entry->rule.list, + &audit_rules_list[entry->rule.listnr]); list_add_tail_rcu(&entry->list, list); } +#ifdef CONFIG_AUDITSYSCALL + if (!dont_count) + audit_n_rules++; - return 0; + if (!audit_match_signal(entry)) + audit_signals++; +#endif + mutex_unlock(&audit_filter_mutex); + + return 0; + +error: + if (watch) + audit_put_watch(watch); /* tmp watch, matches initial get */ + return err; } -/* Remove an existing rule from filterlist. Protected by - * audit_netlink_mutex. */ -static inline int audit_del_rule(struct audit_entry *entry, - struct list_head *list) +/* Remove an existing rule from filterlist. */ +static inline int audit_del_rule(struct audit_entry *entry) { struct audit_entry *e; + struct audit_watch *watch = entry->rule.watch; + struct audit_tree *tree = entry->rule.tree; + struct list_head *list; + LIST_HEAD(inotify_list); + int ret = 0; +#ifdef CONFIG_AUDITSYSCALL + int dont_count = 0; - /* Do not use the _rcu iterator here, since this is the only - * deletion routine. */ - list_for_each_entry(e, list, list) { - if (!audit_compare_rule(&entry->rule, &e->rule)) { - list_del_rcu(&e->list); - call_rcu(&e->rcu, audit_free_rule_rcu); - return 0; - } + /* If either of these, don't count towards total */ + if (entry->rule.listnr == AUDIT_FILTER_USER || + entry->rule.listnr == AUDIT_FILTER_TYPE) + dont_count = 1; +#endif + + mutex_lock(&audit_filter_mutex); + e = audit_find_rule(entry, &list); + if (!e) { + mutex_unlock(&audit_filter_mutex); + ret = -ENOENT; + goto out; } - return -ENOENT; /* No matching rule */ + + if (e->rule.watch) + audit_remove_watch_rule(&e->rule, &inotify_list); + + if (e->rule.tree) + audit_remove_tree_rule(&e->rule); + + list_del_rcu(&e->list); + list_del(&e->rule.list); + call_rcu(&e->rcu, audit_free_rule_rcu); + +#ifdef CONFIG_AUDITSYSCALL + if (!dont_count) + audit_n_rules--; + + if (!audit_match_signal(entry)) + audit_signals--; +#endif + mutex_unlock(&audit_filter_mutex); + + if (!list_empty(&inotify_list)) + audit_inotify_unregister(&inotify_list); + +out: + if (watch) + audit_put_watch(watch); /* match initial get */ + if (tree) + audit_put_tree(tree); /* that's the temporary one */ + + return ret; } /* List rules using struct audit_rule. Exists for backward * compatibility with userspace. */ -static int audit_list(void *_dest) +static void audit_list(int pid, int seq, struct sk_buff_head *q) { - int pid, seq; - int *dest = _dest; - struct audit_entry *entry; + struct sk_buff *skb; + struct audit_krule *r; int i; - pid = dest[0]; - seq = dest[1]; - kfree(dest); - - mutex_lock(&audit_netlink_mutex); - - /* The *_rcu iterators not needed here because we are - always called with audit_netlink_mutex held. */ + /* This is a blocking read, so use audit_filter_mutex instead of rcu + * iterator to sync with list writers. */ for (i=0; irule); + rule = audit_krule_to_rule(r); if (unlikely(!rule)) break; - audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, + skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, rule, sizeof(*rule)); + if (skb) + skb_queue_tail(q, skb); kfree(rule); } } - audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); - - mutex_unlock(&audit_netlink_mutex); - return 0; + skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); + if (skb) + skb_queue_tail(q, skb); } /* List rules using struct audit_rule_data. */ -static int audit_list_rules(void *_dest) +static void audit_list_rules(int pid, int seq, struct sk_buff_head *q) { - int pid, seq; - int *dest = _dest; - struct audit_entry *e; + struct sk_buff *skb; + struct audit_krule *r; int i; - pid = dest[0]; - seq = dest[1]; - kfree(dest); - - mutex_lock(&audit_netlink_mutex); - - /* The *_rcu iterators not needed here because we are - always called with audit_netlink_mutex held. */ + /* This is a blocking read, so use audit_filter_mutex instead of rcu + * iterator to sync with list writers. */ for (i=0; irule); + data = audit_krule_to_data(r); if (unlikely(!data)) break; - audit_send_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, - data, sizeof(*data)); + skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, + data, sizeof(*data) + data->buflen); + if (skb) + skb_queue_tail(q, skb); kfree(data); } } - audit_send_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); + skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); + if (skb) + skb_queue_tail(q, skb); +} - mutex_unlock(&audit_netlink_mutex); - return 0; +/* Log rule additions and removals */ +static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid, + char *action, struct audit_krule *rule, + int res) +{ + struct audit_buffer *ab; + + if (!audit_enabled) + return; + + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); + if (!ab) + return; + audit_log_format(ab, "auid=%u ses=%u", loginuid, sessionid); + if (sid) { + char *ctx = NULL; + u32 len; + if (security_secid_to_secctx(sid, &ctx, &len)) + audit_log_format(ab, " ssid=%u", sid); + else { + audit_log_format(ab, " subj=%s", ctx); + security_release_secctx(ctx, len); + } + } + audit_log_format(ab, " op="); + audit_log_string(ab, action); + audit_log_key(ab, rule->filterkey); + audit_log_format(ab, " list=%d res=%d", rule->listnr, res); + audit_log_end(ab); } /** @@ -586,12 +1095,14 @@ static int audit_list_rules(void *_dest) * @data: payload data * @datasz: size of payload data * @loginuid: loginuid of sender + * @sessionid: sessionid for netlink audit message + * @sid: SE Linux Security ID of sender */ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, - size_t datasz, uid_t loginuid) + size_t datasz, uid_t loginuid, u32 sessionid, u32 sid) { struct task_struct *tsk; - int *dest; + struct audit_netlink_list *dest; int err = 0; struct audit_entry *entry; @@ -603,19 +1114,23 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, * auditctl to read from it... which isn't ever going to * happen if we're actually running in the context of auditctl * trying to _send_ the stuff */ - - dest = kmalloc(2 * sizeof(int), GFP_KERNEL); + + dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); if (!dest) return -ENOMEM; - dest[0] = pid; - dest[1] = seq; + dest->pid = pid; + skb_queue_head_init(&dest->q); + mutex_lock(&audit_filter_mutex); if (type == AUDIT_LIST) - tsk = kthread_run(audit_list, dest, "audit_list"); + audit_list(pid, seq, &dest->q); else - tsk = kthread_run(audit_list_rules, dest, - "audit_list_rules"); + audit_list_rules(pid, seq, &dest->q); + mutex_unlock(&audit_filter_mutex); + + tsk = kthread_run(audit_send_list, dest, "audit_send_list"); if (IS_ERR(tsk)) { + skb_queue_purge(&dest->q); kfree(dest); err = PTR_ERR(tsk); } @@ -629,11 +1144,9 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, if (IS_ERR(entry)) return PTR_ERR(entry); - err = audit_add_rule(entry, - &audit_filter_list[entry->rule.listnr]); - audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, - "auid=%u add rule to list=%d res=%d\n", - loginuid, entry->rule.listnr, !err); + err = audit_add_rule(entry); + audit_log_rule_change(loginuid, sessionid, sid, "add rule", + &entry->rule, !err); if (err) audit_free_rule(entry); @@ -647,11 +1160,9 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, if (IS_ERR(entry)) return PTR_ERR(entry); - err = audit_del_rule(entry, - &audit_filter_list[entry->rule.listnr]); - audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, - "auid=%u remove rule from list=%d res=%d\n", - loginuid, entry->rule.listnr, !err); + err = audit_del_rule(entry); + audit_log_rule_change(loginuid, sessionid, sid, "remove rule", + &entry->rule, !err); audit_free_rule(entry); break; @@ -662,27 +1173,68 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, return err; } -int audit_comparator(const u32 left, const u32 op, const u32 right) +int audit_comparator(u32 left, u32 op, u32 right) { switch (op) { - case AUDIT_EQUAL: + case Audit_equal: return (left == right); - case AUDIT_NOT_EQUAL: + case Audit_not_equal: return (left != right); - case AUDIT_LESS_THAN: + case Audit_lt: return (left < right); - case AUDIT_LESS_THAN_OR_EQUAL: + case Audit_le: return (left <= right); - case AUDIT_GREATER_THAN: + case Audit_gt: return (left > right); - case AUDIT_GREATER_THAN_OR_EQUAL: + case Audit_ge: return (left >= right); + case Audit_bitmask: + return (left & right); + case Audit_bittest: + return ((left & right) == right); + default: + BUG(); + return 0; } - BUG(); - return 0; } +/* Compare given dentry name with last component in given path, + * return of 0 indicates a match. */ +int audit_compare_dname_path(const char *dname, const char *path, + int *dirlen) +{ + int dlen, plen; + const char *p; + + if (!dname || !path) + return 1; + dlen = strlen(dname); + plen = strlen(path); + if (plen < dlen) + return 1; + + /* disregard trailing slashes */ + p = path + plen - 1; + while ((*p == '/') && (p > path)) + p--; + + /* find last path component */ + p = p - dlen + 1; + if (p < path) + return 1; + else if (p > path) { + if (*--p != '/') + return 1; + else + p++; + } + + /* return length of path's directory component */ + if (dirlen) + *dirlen = p - path; + return strncmp(p, dname, dlen); +} static int audit_filter_user_rules(struct netlink_skb_parms *cb, struct audit_krule *rule, @@ -714,16 +1266,15 @@ static int audit_filter_user_rules(struct netlink_skb_parms *cb, } switch (rule->action) { case AUDIT_NEVER: *state = AUDIT_DISABLED; break; - case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break; case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; } return 1; } -int audit_filter_user(struct netlink_skb_parms *cb, int type) +int audit_filter_user(struct netlink_skb_parms *cb) { + enum audit_state state = AUDIT_DISABLED; struct audit_entry *e; - enum audit_state state; int ret = 1; rcu_read_lock(); @@ -743,7 +1294,7 @@ int audit_filter_type(int type) { struct audit_entry *e; int result = 0; - + rcu_read_lock(); if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) goto unlock_and_return; @@ -767,61 +1318,64 @@ unlock_and_return: return result; } -/* Check to see if the rule contains any selinux fields. Returns 1 if there - are selinux fields specified in the rule, 0 otherwise. */ -static inline int audit_rule_has_selinux(struct audit_krule *rule) +static int update_lsm_rule(struct audit_krule *r) { - int i; + struct audit_entry *entry = container_of(r, struct audit_entry, rule); + struct audit_entry *nentry; + struct audit_watch *watch; + struct audit_tree *tree; + int err = 0; - for (i = 0; i < rule->field_count; i++) { - struct audit_field *f = &rule->fields[i]; - switch (f->type) { - case AUDIT_SE_USER: - case AUDIT_SE_ROLE: - case AUDIT_SE_TYPE: - case AUDIT_SE_SEN: - case AUDIT_SE_CLR: - return 1; - } + if (!security_audit_rule_known(r)) + return 0; + + watch = r->watch; + tree = r->tree; + nentry = audit_dupe_rule(r, watch); + if (IS_ERR(nentry)) { + /* save the first error encountered for the + * return value */ + err = PTR_ERR(nentry); + audit_panic("error updating LSM filters"); + if (watch) + list_del(&r->rlist); + list_del_rcu(&entry->list); + list_del(&r->list); + } else { + if (watch) { + list_add(&nentry->rule.rlist, audit_watch_rules(watch)); + list_del(&r->rlist); + } else if (tree) + list_replace_init(&r->rlist, &nentry->rule.rlist); + list_replace_rcu(&entry->list, &nentry->list); + list_replace(&r->list, &nentry->rule.list); } + call_rcu(&entry->rcu, audit_free_rule_rcu); - return 0; + return err; } -/* This function will re-initialize the se_rule field of all applicable rules. - * It will traverse the filter lists serarching for rules that contain selinux +/* This function will re-initialize the lsm_rule field of all applicable rules. + * It will traverse the filter lists serarching for rules that contain LSM * specific filter fields. When such a rule is found, it is copied, the - * selinux field is re-initialized, and the old rule is replaced with the + * LSM field is re-initialized, and the old rule is replaced with the * updated rule. */ -int selinux_audit_rule_update(void) +int audit_update_lsm_rules(void) { - struct audit_entry *entry, *n, *nentry; + struct audit_krule *r, *n; int i, err = 0; - /* audit_netlink_mutex synchronizes the writers */ - mutex_lock(&audit_netlink_mutex); + /* audit_filter_mutex synchronizes the writers */ + mutex_lock(&audit_filter_mutex); for (i = 0; i < AUDIT_NR_FILTERS; i++) { - list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) { - if (!audit_rule_has_selinux(&entry->rule)) - continue; - - nentry = audit_dupe_rule(&entry->rule); - if (unlikely(IS_ERR(nentry))) { - /* save the first error encountered for the - * return value */ - if (!err) - err = PTR_ERR(nentry); - audit_panic("error updating selinux filters"); - list_del_rcu(&entry->list); - } else { - list_replace_rcu(&entry->list, &nentry->list); - } - call_rcu(&entry->rcu, audit_free_rule_rcu); + list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { + int res = update_lsm_rule(r); + if (!err) + err = res; } } - - mutex_unlock(&audit_netlink_mutex); + mutex_unlock(&audit_filter_mutex); return err; }