From fe7752bab26a9ac0651b695ad4f55659761f68f7 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Thu, 15 Dec 2005 18:33:52 +0000 Subject: [PATCH] Fix audit record filtering with !CONFIG_AUDITSYSCALL This fixes the per-user and per-message-type filtering when syscall auditing isn't enabled. [AV: folded followup fix from the same author] Signed-off-by: David Woodhouse Signed-off-by: Al Viro --- kernel/auditfilter.c | 378 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 378 insertions(+) create mode 100644 kernel/auditfilter.c (limited to 'kernel/auditfilter.c') diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c new file mode 100644 index 000000000000..7f347c360876 --- /dev/null +++ b/kernel/auditfilter.c @@ -0,0 +1,378 @@ +/* auditfilter.c -- filtering of audit events + * + * Copyright 2003-2004 Red Hat, Inc. + * Copyright 2005 Hewlett-Packard Development Company, L.P. + * Copyright 2005 IBM Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#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. */ +struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { + LIST_HEAD_INIT(audit_filter_list[0]), + LIST_HEAD_INIT(audit_filter_list[1]), + LIST_HEAD_INIT(audit_filter_list[2]), + LIST_HEAD_INIT(audit_filter_list[3]), + LIST_HEAD_INIT(audit_filter_list[4]), + LIST_HEAD_INIT(audit_filter_list[5]), +#if AUDIT_NR_FILTERS != 6 +#error Fix audit_filter_list initialiser +#endif +}; + +/* Copy rule from user-space to kernel-space. Called from + * audit_add_rule during AUDIT_ADD. */ +static inline int audit_copy_rule(struct audit_rule *d, struct audit_rule *s) +{ + int i; + + if (s->action != AUDIT_NEVER + && s->action != AUDIT_POSSIBLE + && s->action != AUDIT_ALWAYS) + return -1; + if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS) + return -1; + if ((s->flags & ~AUDIT_FILTER_PREPEND) >= AUDIT_NR_FILTERS) + return -1; + + d->flags = s->flags; + d->action = s->action; + d->field_count = s->field_count; + for (i = 0; i < d->field_count; i++) { + d->fields[i] = s->fields[i]; + d->values[i] = s->values[i]; + } + for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i]; + return 0; +} + +/* Check to see if two rules are identical. It is called from + * audit_add_rule during AUDIT_ADD and + * audit_del_rule during AUDIT_DEL. */ +static inline int audit_compare_rule(struct audit_rule *a, struct audit_rule *b) +{ + int i; + + if (a->flags != b->flags) + return 1; + + if (a->action != b->action) + return 1; + + if (a->field_count != b->field_count) + return 1; + + for (i = 0; i < a->field_count; i++) { + if (a->fields[i] != b->fields[i] + || a->values[i] != b->values[i]) + return 1; + } + + for (i = 0; i < AUDIT_BITMASK_SIZE; i++) + if (a->mask[i] != b->mask[i]) + return 1; + + return 0; +} + +/* Note that audit_add_rule and audit_del_rule are called via + * audit_receive() in audit.c, and are protected by + * audit_netlink_sem. */ +static inline int audit_add_rule(struct audit_rule *rule, + struct list_head *list) +{ + struct audit_entry *entry; + int i; + + /* Do not use the _rcu iterator here, since this is the only + * addition routine. */ + list_for_each_entry(entry, list, list) { + if (!audit_compare_rule(rule, &entry->rule)) { + return -EEXIST; + } + } + + for (i = 0; i < rule->field_count; i++) { + if (rule->fields[i] & AUDIT_UNUSED_BITS) + return -EINVAL; + if ( rule->fields[i] & AUDIT_NEGATE ) + rule->fields[i] |= AUDIT_NOT_EQUAL; + else if ( (rule->fields[i] & AUDIT_OPERATORS) == 0 ) + rule->fields[i] |= AUDIT_EQUAL; + rule->fields[i] &= (~AUDIT_NEGATE); + } + + if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL))) + return -ENOMEM; + if (audit_copy_rule(&entry->rule, rule)) { + kfree(entry); + return -EINVAL; + } + + if (entry->rule.flags & AUDIT_FILTER_PREPEND) { + entry->rule.flags &= ~AUDIT_FILTER_PREPEND; + list_add_rcu(&entry->list, list); + } else { + list_add_tail_rcu(&entry->list, list); + } + + return 0; +} + +static inline void audit_free_rule(struct rcu_head *head) +{ + struct audit_entry *e = container_of(head, struct audit_entry, rcu); + kfree(e); +} + +/* Note that audit_add_rule and audit_del_rule are called via + * audit_receive() in audit.c, and are protected by + * audit_netlink_sem. */ +static inline int audit_del_rule(struct audit_rule *rule, + struct list_head *list) +{ + struct audit_entry *e; + + /* 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(rule, &e->rule)) { + list_del_rcu(&e->list); + call_rcu(&e->rcu, audit_free_rule); + return 0; + } + } + return -ENOENT; /* No matching rule */ +} + +static int audit_list_rules(void *_dest) +{ + int pid, seq; + int *dest = _dest; + struct audit_entry *entry; + int i; + + pid = dest[0]; + seq = dest[1]; + kfree(dest); + + down(&audit_netlink_sem); + + /* The *_rcu iterators not needed here because we are + always called with audit_netlink_sem held. */ + for (i=0; irule, sizeof(entry->rule)); + } + audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); + + up(&audit_netlink_sem); + return 0; +} + +/** + * audit_receive_filter - apply all rules to the specified message type + * @type: audit message type + * @pid: target pid for netlink audit messages + * @uid: target uid for netlink audit messages + * @seq: netlink audit message sequence (serial) number + * @data: payload data + * @loginuid: loginuid of sender + */ +int audit_receive_filter(int type, int pid, int uid, int seq, void *data, + uid_t loginuid) +{ + struct task_struct *tsk; + int *dest; + int err = 0; + unsigned listnr; + + switch (type) { + case AUDIT_LIST: + /* We can't just spew out the rules here because we might fill + * the available socket buffer space and deadlock waiting for + * 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); + if (!dest) + return -ENOMEM; + dest[0] = pid; + dest[1] = seq; + + tsk = kthread_run(audit_list_rules, dest, "audit_list_rules"); + if (IS_ERR(tsk)) { + kfree(dest); + err = PTR_ERR(tsk); + } + break; + case AUDIT_ADD: + listnr = ((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND; + switch(listnr) { + default: + return -EINVAL; + + case AUDIT_FILTER_USER: + case AUDIT_FILTER_TYPE: +#ifdef CONFIG_AUDITSYSCALL + case AUDIT_FILTER_ENTRY: + case AUDIT_FILTER_EXIT: + case AUDIT_FILTER_TASK: +#endif + ; + } + err = audit_add_rule(data, &audit_filter_list[listnr]); + if (!err) + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, + "auid=%u added an audit rule\n", loginuid); + break; + case AUDIT_DEL: + listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND; + if (listnr >= AUDIT_NR_FILTERS) + return -EINVAL; + + err = audit_del_rule(data, &audit_filter_list[listnr]); + if (!err) + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, + "auid=%u removed an audit rule\n", loginuid); + break; + default: + return -EINVAL; + } + + return err; +} + +int audit_comparator(const u32 left, const u32 op, const u32 right) +{ + switch (op) { + case AUDIT_EQUAL: + return (left == right); + case AUDIT_NOT_EQUAL: + return (left != right); + case AUDIT_LESS_THAN: + return (left < right); + case AUDIT_LESS_THAN_OR_EQUAL: + return (left <= right); + case AUDIT_GREATER_THAN: + return (left > right); + case AUDIT_GREATER_THAN_OR_EQUAL: + return (left >= right); + default: + return -EINVAL; + } +} + + + +static int audit_filter_user_rules(struct netlink_skb_parms *cb, + struct audit_rule *rule, + enum audit_state *state) +{ + int i; + + for (i = 0; i < rule->field_count; i++) { + u32 field = rule->fields[i] & ~AUDIT_OPERATORS; + u32 op = rule->fields[i] & AUDIT_OPERATORS; + u32 value = rule->values[i]; + int result = 0; + + switch (field) { + case AUDIT_PID: + result = audit_comparator(cb->creds.pid, op, value); + break; + case AUDIT_UID: + result = audit_comparator(cb->creds.uid, op, value); + break; + case AUDIT_GID: + result = audit_comparator(cb->creds.gid, op, value); + break; + case AUDIT_LOGINUID: + result = audit_comparator(cb->loginuid, op, value); + break; + } + + if (!result) + return 0; + } + switch (rule->action) { + case AUDIT_NEVER: *state = AUDIT_DISABLED; break; + case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break; + case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; + } + return 1; +} + +int audit_filter_user(struct netlink_skb_parms *cb, int type) +{ + struct audit_entry *e; + enum audit_state state; + int ret = 1; + + rcu_read_lock(); + list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { + if (audit_filter_user_rules(cb, &e->rule, &state)) { + if (state == AUDIT_DISABLED) + ret = 0; + break; + } + } + rcu_read_unlock(); + + return ret; /* Audit by default */ +} + +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; + + list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], + list) { + struct audit_rule *rule = &e->rule; + int i; + for (i = 0; i < rule->field_count; i++) { + u32 field = rule->fields[i] & ~AUDIT_OPERATORS; + u32 op = rule->fields[i] & AUDIT_OPERATORS; + u32 value = rule->values[i]; + if ( field == AUDIT_MSGTYPE ) { + result = audit_comparator(type, op, value); + if (!result) + break; + } + } + if (result) + goto unlock_and_return; + } +unlock_and_return: + rcu_read_unlock(); + return result; +} + + -- cgit v1.2.3 From d884596f44ef5a0bcd8a66405dc04902aeaa6fc7 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Fri, 16 Dec 2005 10:48:28 +0000 Subject: [PATCH] Minor cosmetic cleanups to the code moved into auditfilter.c Signed-off-by: David Woodhouse --- kernel/auditfilter.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'kernel/auditfilter.c') diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 7f347c360876..a3a32752f973 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -69,7 +69,7 @@ static inline int audit_copy_rule(struct audit_rule *d, struct audit_rule *s) /* Check to see if two rules are identical. It is called from * audit_add_rule during AUDIT_ADD and * audit_del_rule during AUDIT_DEL. */ -static inline int audit_compare_rule(struct audit_rule *a, struct audit_rule *b) +static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b) { int i; @@ -107,19 +107,18 @@ static inline int audit_add_rule(struct audit_rule *rule, /* Do not use the _rcu iterator here, since this is the only * addition routine. */ list_for_each_entry(entry, list, list) { - if (!audit_compare_rule(rule, &entry->rule)) { + if (!audit_compare_rule(rule, &entry->rule)) return -EEXIST; - } } for (i = 0; i < rule->field_count; i++) { if (rule->fields[i] & AUDIT_UNUSED_BITS) return -EINVAL; - if ( rule->fields[i] & AUDIT_NEGATE ) + if ( rule->fields[i] & AUDIT_NEGATE) rule->fields[i] |= AUDIT_NOT_EQUAL; else if ( (rule->fields[i] & AUDIT_OPERATORS) == 0 ) rule->fields[i] |= AUDIT_EQUAL; - rule->fields[i] &= (~AUDIT_NEGATE); + rule->fields[i] &= ~AUDIT_NEGATE; } if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL))) @@ -374,5 +373,3 @@ unlock_and_return: rcu_read_unlock(); return result; } - - -- cgit v1.2.3 From 93315ed6dd12dacfc941f9eb8ca0293aadf99793 Mon Sep 17 00:00:00 2001 From: Amy Griffis Date: Tue, 7 Feb 2006 12:05:27 -0500 Subject: [PATCH] audit string fields interface + consumer Updated patch to dynamically allocate audit rule fields in kernel's internal representation. Added unlikely() calls for testing memory allocation result. Amy Griffis wrote: [Wed Jan 11 2006, 02:02:31PM EST] > Modify audit's kernel-userspace interface to allow the specification > of string fields in audit rules. > > Signed-off-by: Amy Griffis Signed-off-by: Al Viro (cherry picked from 5ffc4a863f92351b720fe3e9c5cd647accff9e03 commit) --- kernel/auditfilter.c | 467 +++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 357 insertions(+), 110 deletions(-) (limited to 'kernel/auditfilter.c') diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index a3a32752f973..686d514a3518 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -40,52 +40,279 @@ struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { #endif }; -/* Copy rule from user-space to kernel-space. Called from - * audit_add_rule during AUDIT_ADD. */ -static inline int audit_copy_rule(struct audit_rule *d, struct audit_rule *s) +static inline void audit_free_rule(struct audit_entry *e) { + kfree(e->rule.fields); + kfree(e); +} + +static inline void audit_free_rule_rcu(struct rcu_head *head) +{ + struct audit_entry *e = container_of(head, struct audit_entry, rcu); + audit_free_rule(e); +} + +/* Unpack a filter field's string representation from user-space + * buffer. */ +static __attribute__((unused)) char *audit_unpack_string(void **bufp, size_t *remain, size_t len) +{ + char *str; + + if (!*bufp || (len == 0) || (len > *remain)) + return ERR_PTR(-EINVAL); + + /* Of the currently implemented string fields, PATH_MAX + * defines the longest valid length. + */ + if (len > PATH_MAX) + return ERR_PTR(-ENAMETOOLONG); + + str = kmalloc(len + 1, GFP_KERNEL); + if (unlikely(!str)) + return ERR_PTR(-ENOMEM); + + memcpy(str, *bufp, len); + str[len] = 0; + *bufp += len; + *remain -= len; + + return str; +} + +/* Common user-space to kernel rule translation. */ +static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) +{ + unsigned listnr; + struct audit_entry *entry; + struct audit_field *fields; + int i, err; + + err = -EINVAL; + listnr = rule->flags & ~AUDIT_FILTER_PREPEND; + switch(listnr) { + default: + goto exit_err; + case AUDIT_FILTER_USER: + case AUDIT_FILTER_TYPE: +#ifdef CONFIG_AUDITSYSCALL + case AUDIT_FILTER_ENTRY: + case AUDIT_FILTER_EXIT: + case AUDIT_FILTER_TASK: +#endif + ; + } + if (rule->action != AUDIT_NEVER && rule->action != AUDIT_POSSIBLE && + rule->action != AUDIT_ALWAYS) + goto exit_err; + if (rule->field_count > AUDIT_MAX_FIELDS) + goto exit_err; + + err = -ENOMEM; + entry = kmalloc(sizeof(*entry), GFP_KERNEL); + if (unlikely(!entry)) + goto exit_err; + fields = kmalloc(sizeof(*fields) * rule->field_count, GFP_KERNEL); + if (unlikely(!fields)) { + kfree(entry); + goto exit_err; + } + + memset(&entry->rule, 0, sizeof(struct audit_krule)); + memset(fields, 0, sizeof(struct audit_field)); + + entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; + entry->rule.listnr = listnr; + entry->rule.action = rule->action; + entry->rule.field_count = rule->field_count; + entry->rule.fields = fields; + + for (i = 0; i < AUDIT_BITMASK_SIZE; i++) + entry->rule.mask[i] = rule->mask[i]; + + return entry; + +exit_err: + return ERR_PTR(err); +} + +/* 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) +{ + struct audit_entry *entry; + int err = 0; int i; - if (s->action != AUDIT_NEVER - && s->action != AUDIT_POSSIBLE - && s->action != AUDIT_ALWAYS) - return -1; - if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS) - return -1; - if ((s->flags & ~AUDIT_FILTER_PREPEND) >= AUDIT_NR_FILTERS) - return -1; - - d->flags = s->flags; - d->action = s->action; - d->field_count = s->field_count; - for (i = 0; i < d->field_count; i++) { - d->fields[i] = s->fields[i]; - d->values[i] = s->values[i]; + entry = audit_to_entry_common(rule); + if (IS_ERR(entry)) + goto exit_nofree; + + for (i = 0; i < rule->field_count; i++) { + struct audit_field *f = &entry->rule.fields[i]; + + if (rule->fields[i] & AUDIT_UNUSED_BITS) { + err = -EINVAL; + goto exit_free; + } + + f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); + f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); + f->val = rule->values[i]; + + entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1; + if (f->op & AUDIT_NEGATE) + f->op |= AUDIT_NOT_EQUAL; + else if (!(f->op & AUDIT_OPERATORS)) + f->op |= AUDIT_EQUAL; + f->op &= ~AUDIT_NEGATE; } - for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i]; - return 0; + +exit_nofree: + return entry; + +exit_free: + audit_free_rule(entry); + return ERR_PTR(err); } -/* Check to see if two rules are identical. It is called from - * audit_add_rule during AUDIT_ADD and - * audit_del_rule during AUDIT_DEL. */ -static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b) +/* Translate struct audit_rule_data to kernel's rule respresentation. */ +static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, + size_t datasz) { + int err = 0; + struct audit_entry *entry; + void *bufp; + /* size_t remain = datasz - sizeof(struct audit_rule_data); */ int i; - if (a->flags != b->flags) - return 1; + entry = audit_to_entry_common((struct audit_rule *)data); + if (IS_ERR(entry)) + goto exit_nofree; - if (a->action != b->action) - return 1; + bufp = data->buf; + entry->rule.vers_ops = 2; + for (i = 0; i < data->field_count; i++) { + struct audit_field *f = &entry->rule.fields[i]; + + err = -EINVAL; + if (!(data->fieldflags[i] & AUDIT_OPERATORS) || + data->fieldflags[i] & ~AUDIT_OPERATORS) + goto exit_free; + + f->op = data->fieldflags[i] & AUDIT_OPERATORS; + f->type = data->fields[i]; + switch(f->type) { + /* call type-specific conversion routines here */ + default: + f->val = data->values[i]; + } + } + +exit_nofree: + return entry; + +exit_free: + audit_free_rule(entry); + return ERR_PTR(err); +} + +/* Pack a filter field's string representation into data block. */ +static inline size_t audit_pack_string(void **bufp, char *str) +{ + size_t len = strlen(str); + + memcpy(*bufp, str, len); + *bufp += len; + + return len; +} + +/* Translate kernel rule respresentation to struct audit_rule. + * Exists for backward compatibility with userspace. */ +static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) +{ + struct audit_rule *rule; + int i; + + rule = kmalloc(sizeof(*rule), GFP_KERNEL); + if (unlikely(!rule)) + return ERR_PTR(-ENOMEM); + memset(rule, 0, sizeof(*rule)); + + rule->flags = krule->flags | krule->listnr; + rule->action = krule->action; + rule->field_count = krule->field_count; + for (i = 0; i < rule->field_count; i++) { + rule->values[i] = krule->fields[i].val; + rule->fields[i] = krule->fields[i].type; + + if (krule->vers_ops == 1) { + if (krule->fields[i].op & AUDIT_NOT_EQUAL) + rule->fields[i] |= AUDIT_NEGATE; + } else { + rule->fields[i] |= krule->fields[i].op; + } + } + for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; + + return rule; +} - if (a->field_count != b->field_count) +/* Translate kernel rule respresentation to struct audit_rule_data. */ +static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) +{ + struct audit_rule_data *data; + void *bufp; + int i; + + data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); + if (unlikely(!data)) + return ERR_PTR(-ENOMEM); + memset(data, 0, sizeof(*data)); + + data->flags = krule->flags | krule->listnr; + data->action = krule->action; + data->field_count = krule->field_count; + bufp = data->buf; + for (i = 0; i < data->field_count; i++) { + struct audit_field *f = &krule->fields[i]; + + data->fields[i] = f->type; + data->fieldflags[i] = f->op; + switch(f->type) { + /* call type-specific conversion routines here */ + default: + data->values[i] = f->val; + } + } + for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; + + return data; +} + +/* Compare two rules in kernel format. Considered success if rules + * don't match. */ +static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) +{ + int i; + + if (a->flags != b->flags || + a->listnr != b->listnr || + a->action != b->action || + a->field_count != b->field_count) return 1; for (i = 0; i < a->field_count; i++) { - if (a->fields[i] != b->fields[i] - || a->values[i] != b->values[i]) + if (a->fields[i].type != b->fields[i].type || + a->fields[i].op != b->fields[i].op) return 1; + + switch(a->fields[i].type) { + /* call type-specific comparison routines here */ + default: + if (a->fields[i].val != b->fields[i].val) + return 1; + } } for (i = 0; i < AUDIT_BITMASK_SIZE; i++) @@ -95,41 +322,21 @@ static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b) return 0; } -/* Note that audit_add_rule and audit_del_rule are called via - * audit_receive() in audit.c, and are protected by +/* Add rule to given filterlist if not a duplicate. Protected by * audit_netlink_sem. */ -static inline int audit_add_rule(struct audit_rule *rule, +static inline int audit_add_rule(struct audit_entry *entry, struct list_head *list) { - struct audit_entry *entry; - int i; + struct audit_entry *e; /* Do not use the _rcu iterator here, since this is the only * addition routine. */ - list_for_each_entry(entry, list, list) { - if (!audit_compare_rule(rule, &entry->rule)) + list_for_each_entry(e, list, list) { + if (!audit_compare_rule(&entry->rule, &e->rule)) return -EEXIST; } - for (i = 0; i < rule->field_count; i++) { - if (rule->fields[i] & AUDIT_UNUSED_BITS) - return -EINVAL; - if ( rule->fields[i] & AUDIT_NEGATE) - rule->fields[i] |= AUDIT_NOT_EQUAL; - else if ( (rule->fields[i] & AUDIT_OPERATORS) == 0 ) - rule->fields[i] |= AUDIT_EQUAL; - rule->fields[i] &= ~AUDIT_NEGATE; - } - - if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL))) - return -ENOMEM; - if (audit_copy_rule(&entry->rule, rule)) { - kfree(entry); - return -EINVAL; - } - if (entry->rule.flags & AUDIT_FILTER_PREPEND) { - entry->rule.flags &= ~AUDIT_FILTER_PREPEND; list_add_rcu(&entry->list, list); } else { list_add_tail_rcu(&entry->list, list); @@ -138,16 +345,9 @@ static inline int audit_add_rule(struct audit_rule *rule, return 0; } -static inline void audit_free_rule(struct rcu_head *head) -{ - struct audit_entry *e = container_of(head, struct audit_entry, rcu); - kfree(e); -} - -/* Note that audit_add_rule and audit_del_rule are called via - * audit_receive() in audit.c, and are protected by +/* Remove an existing rule from filterlist. Protected by * audit_netlink_sem. */ -static inline int audit_del_rule(struct audit_rule *rule, +static inline int audit_del_rule(struct audit_entry *entry, struct list_head *list) { struct audit_entry *e; @@ -155,16 +355,18 @@ static inline int audit_del_rule(struct audit_rule *rule, /* 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(rule, &e->rule)) { + if (!audit_compare_rule(&entry->rule, &e->rule)) { list_del_rcu(&e->list); - call_rcu(&e->rcu, audit_free_rule); + call_rcu(&e->rcu, audit_free_rule_rcu); return 0; } } return -ENOENT; /* No matching rule */ } -static int audit_list_rules(void *_dest) +/* List rules using struct audit_rule. Exists for backward + * compatibility with userspace. */ +static int audit_list(void *_dest) { int pid, seq; int *dest = _dest; @@ -180,9 +382,16 @@ static int audit_list_rules(void *_dest) /* The *_rcu iterators not needed here because we are always called with audit_netlink_sem held. */ for (i=0; irule); + if (unlikely(!rule)) + break; audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, - &entry->rule, sizeof(entry->rule)); + rule, sizeof(*rule)); + kfree(rule); + } } audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); @@ -190,6 +399,40 @@ static int audit_list_rules(void *_dest) return 0; } +/* List rules using struct audit_rule_data. */ +static int audit_list_rules(void *_dest) +{ + int pid, seq; + int *dest = _dest; + struct audit_entry *e; + int i; + + pid = dest[0]; + seq = dest[1]; + kfree(dest); + + down(&audit_netlink_sem); + + /* The *_rcu iterators not needed here because we are + always called with audit_netlink_sem held. */ + for (i=0; irule); + if (unlikely(!data)) + break; + audit_send_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, + data, sizeof(*data)); + kfree(data); + } + } + audit_send_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); + + up(&audit_netlink_sem); + return 0; +} + /** * audit_receive_filter - apply all rules to the specified message type * @type: audit message type @@ -197,18 +440,20 @@ static int audit_list_rules(void *_dest) * @uid: target uid for netlink audit messages * @seq: netlink audit message sequence (serial) number * @data: payload data + * @datasz: size of payload data * @loginuid: loginuid of sender */ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, - uid_t loginuid) + size_t datasz, uid_t loginuid) { struct task_struct *tsk; int *dest; - int err = 0; - unsigned listnr; + int err = 0; + struct audit_entry *entry; switch (type) { case AUDIT_LIST: + case AUDIT_LIST_RULES: /* We can't just spew out the rules here because we might fill * the available socket buffer space and deadlock waiting for * auditctl to read from it... which isn't ever going to @@ -221,41 +466,48 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, dest[0] = pid; dest[1] = seq; - tsk = kthread_run(audit_list_rules, dest, "audit_list_rules"); + if (type == AUDIT_LIST) + tsk = kthread_run(audit_list, dest, "audit_list"); + else + tsk = kthread_run(audit_list_rules, dest, + "audit_list_rules"); if (IS_ERR(tsk)) { kfree(dest); err = PTR_ERR(tsk); } break; case AUDIT_ADD: - listnr = ((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND; - switch(listnr) { - default: - return -EINVAL; - - case AUDIT_FILTER_USER: - case AUDIT_FILTER_TYPE: -#ifdef CONFIG_AUDITSYSCALL - case AUDIT_FILTER_ENTRY: - case AUDIT_FILTER_EXIT: - case AUDIT_FILTER_TASK: -#endif - ; - } - err = audit_add_rule(data, &audit_filter_list[listnr]); + case AUDIT_ADD_RULE: + if (type == AUDIT_ADD) + entry = audit_rule_to_entry(data); + else + entry = audit_data_to_entry(data, datasz); + if (IS_ERR(entry)) + return PTR_ERR(entry); + + err = audit_add_rule(entry, + &audit_filter_list[entry->rule.listnr]); if (!err) audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, "auid=%u added an audit rule\n", loginuid); + else + audit_free_rule(entry); break; case AUDIT_DEL: - listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND; - if (listnr >= AUDIT_NR_FILTERS) - return -EINVAL; - - err = audit_del_rule(data, &audit_filter_list[listnr]); + case AUDIT_DEL_RULE: + if (type == AUDIT_DEL) + entry = audit_rule_to_entry(data); + else + entry = audit_data_to_entry(data, datasz); + if (IS_ERR(entry)) + return PTR_ERR(entry); + + err = audit_del_rule(entry, + &audit_filter_list[entry->rule.listnr]); if (!err) audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, "auid=%u removed an audit rule\n", loginuid); + audit_free_rule(entry); break; default: return -EINVAL; @@ -287,29 +539,27 @@ int audit_comparator(const u32 left, const u32 op, const u32 right) static int audit_filter_user_rules(struct netlink_skb_parms *cb, - struct audit_rule *rule, + struct audit_krule *rule, enum audit_state *state) { int i; for (i = 0; i < rule->field_count; i++) { - u32 field = rule->fields[i] & ~AUDIT_OPERATORS; - u32 op = rule->fields[i] & AUDIT_OPERATORS; - u32 value = rule->values[i]; + struct audit_field *f = &rule->fields[i]; int result = 0; - switch (field) { + switch (f->type) { case AUDIT_PID: - result = audit_comparator(cb->creds.pid, op, value); + result = audit_comparator(cb->creds.pid, f->op, f->val); break; case AUDIT_UID: - result = audit_comparator(cb->creds.uid, op, value); + result = audit_comparator(cb->creds.uid, f->op, f->val); break; case AUDIT_GID: - result = audit_comparator(cb->creds.gid, op, value); + result = audit_comparator(cb->creds.gid, f->op, f->val); break; case AUDIT_LOGINUID: - result = audit_comparator(cb->loginuid, op, value); + result = audit_comparator(cb->loginuid, f->op, f->val); break; } @@ -354,14 +604,11 @@ int audit_filter_type(int type) list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], list) { - struct audit_rule *rule = &e->rule; int i; - for (i = 0; i < rule->field_count; i++) { - u32 field = rule->fields[i] & ~AUDIT_OPERATORS; - u32 op = rule->fields[i] & AUDIT_OPERATORS; - u32 value = rule->values[i]; - if ( field == AUDIT_MSGTYPE ) { - result = audit_comparator(type, op, value); + for (i = 0; i < e->rule.field_count; i++) { + struct audit_field *f = &e->rule.fields[i]; + if (f->type == AUDIT_MSGTYPE) { + result = audit_comparator(type, f->op, f->val); if (!result) break; } -- cgit v1.2.3 From 5d3301088f7e412992d9e61cc3604cbdff3090ff Mon Sep 17 00:00:00 2001 From: Steve Grubb Date: Mon, 9 Jan 2006 09:48:17 -0500 Subject: [PATCH] add/remove rule update Hi, The following patch adds a little more information to the add/remove rule message emitted by the kernel. Signed-off-by: Steve Grubb Signed-off-by: Al Viro --- kernel/auditfilter.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) (limited to 'kernel/auditfilter.c') diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 686d514a3518..35f8fa82bb8b 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -487,10 +487,11 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, err = audit_add_rule(entry, &audit_filter_list[entry->rule.listnr]); - if (!err) - audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, - "auid=%u added an audit rule\n", loginuid); - else + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, + "auid=%u add rule to list=%d res=%d\n", + loginuid, entry->rule.listnr, !err); + + if (err) audit_free_rule(entry); break; case AUDIT_DEL: @@ -504,9 +505,10 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data, err = audit_del_rule(entry, &audit_filter_list[entry->rule.listnr]); - if (!err) - audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, - "auid=%u removed an audit rule\n", loginuid); + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, + "auid=%u remove rule from list=%d res=%d\n", + loginuid, entry->rule.listnr, !err); + audit_free_rule(entry); break; default: -- cgit v1.2.3 From d9d9ec6e2c45b22282cd36cf92fcb23d504350a8 Mon Sep 17 00:00:00 2001 From: Dustin Kirkland Date: Thu, 16 Feb 2006 13:40:01 -0600 Subject: [PATCH] Fix audit operators Darrel Goeddel initiated a discussion on IRC regarding the possibility of audit_comparator() returning -EINVAL signaling an invalid operator. It is possible when creating the rule to assure that the operator is one of the 6 sane values. Here's a snip from include/linux/audit.h Note that 0 (nonsense) and 7 (all operators) are not valid values for an operator. ... /* These are the supported operators. * 4 2 1 * = > < * ------- * 0 0 0 0 nonsense * 0 0 1 1 < * 0 1 0 2 > * 0 1 1 3 != * 1 0 0 4 = * 1 0 1 5 <= * 1 1 0 6 >= * 1 1 1 7 all operators */ ... Furthermore, prior to adding these extended operators, flagging the AUDIT_NEGATE bit implied !=, and otherwise == was assumed. The following code forces the operator to be != if the AUDIT_NEGATE bit was flipped on. And if no operator was specified, == is assumed. The only invalid condition is if the AUDIT_NEGATE bit is off and all of the AUDIT_EQUAL, AUDIT_LESS_THAN, and AUDIT_GREATER_THAN bits are on--clearly a nonsensical operator. Now that this is handled at rule insertion time, the default -EINVAL return of audit_comparator() is eliminated such that the function can only return 1 or 0. If this is acceptable, let's get this applied to the current tree. :-Dustin -- Signed-off-by: Al Viro (cherry picked from 9bf0a8e137040f87d1b563336d4194e38fb2ba1a commit) --- kernel/auditfilter.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'kernel/auditfilter.c') diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index 35f8fa82bb8b..b85fd8cce11f 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -160,11 +160,17 @@ static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) f->val = rule->values[i]; 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 & AUDIT_OPERATORS)) - f->op |= AUDIT_EQUAL; - 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; + goto exit_free; + } } exit_nofree: @@ -533,9 +539,9 @@ int audit_comparator(const u32 left, const u32 op, const u32 right) return (left > right); case AUDIT_GREATER_THAN_OR_EQUAL: return (left >= right); - default: - return -EINVAL; } + BUG(); + return 0; } -- cgit v1.2.3 From 5a0bbce58bb25bd756f7ec437319d6ed2201a18b Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 7 Mar 2006 23:51:38 -0800 Subject: [PATCH] sem2mutex: audit_netlink_sem Semaphore to mutex conversion. The conversion was generated via scripts, and the result was validated automatically via a script as well. Signed-off-by: Ingo Molnar Cc: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- kernel/auditfilter.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel/auditfilter.c') diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index b85fd8cce11f..d3a8539f3a83 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -329,7 +329,7 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) } /* Add rule to given filterlist if not a duplicate. Protected by - * audit_netlink_sem. */ + * audit_netlink_mutex. */ static inline int audit_add_rule(struct audit_entry *entry, struct list_head *list) { @@ -352,7 +352,7 @@ static inline int audit_add_rule(struct audit_entry *entry, } /* Remove an existing rule from filterlist. Protected by - * audit_netlink_sem. */ + * audit_netlink_mutex. */ static inline int audit_del_rule(struct audit_entry *entry, struct list_head *list) { @@ -383,10 +383,10 @@ static int audit_list(void *_dest) seq = dest[1]; kfree(dest); - down(&audit_netlink_sem); + mutex_lock(&audit_netlink_mutex); /* The *_rcu iterators not needed here because we are - always called with audit_netlink_sem held. */ + always called with audit_netlink_mutex held. */ for (i=0; i