Smack: Integrate Smack with Audit
Setup the new Audit hooks for Smack. SELinux Audit rule fields are recycled to avoid `auditd' userspace modifications. Currently only equality testing is supported on labels acting as a subject (AUDIT_SUBJ_USER) or as an object (AUDIT_OBJ_USER). Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
This commit is contained in:
Ahmed S. Darwish
James Morris
parent
780db6c104
commit
d20bdda6d4
|
|
@ -26,6 +26,7 @@
|
|||
#include <linux/pipe_fs_i.h>
|
||||
#include <net/netlabel.h>
|
||||
#include <net/cipso_ipv4.h>
|
||||
#include <linux/audit.h>
|
||||
|
||||
#include "smack.h"
|
||||
|
||||
|
|
@ -752,6 +753,18 @@ static int smack_inode_listsecurity(struct inode *inode, char *buffer,
|
|||
return -EINVAL;
|
||||
}
|
||||
|
||||
/**
|
||||
* smack_inode_getsecid - Extract inode's security id
|
||||
* @inode: inode to extract the info from
|
||||
* @secid: where result will be saved
|
||||
*/
|
||||
static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
|
||||
{
|
||||
struct inode_smack *isp = inode->i_security;
|
||||
|
||||
*secid = smack_to_secid(isp->smk_inode);
|
||||
}
|
||||
|
||||
/*
|
||||
* File Hooks
|
||||
*/
|
||||
|
|
@ -1805,6 +1818,18 @@ static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
|
|||
return smk_curacc(isp, may);
|
||||
}
|
||||
|
||||
/**
|
||||
* smack_ipc_getsecid - Extract smack security id
|
||||
* @ipcp: the object permissions
|
||||
* @secid: where result will be saved
|
||||
*/
|
||||
static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
|
||||
{
|
||||
char *smack = ipp->security;
|
||||
|
||||
*secid = smack_to_secid(smack);
|
||||
}
|
||||
|
||||
/* module stacking operations */
|
||||
|
||||
/**
|
||||
|
|
@ -2381,6 +2406,124 @@ static int smack_key_permission(key_ref_t key_ref,
|
|||
}
|
||||
#endif /* CONFIG_KEYS */
|
||||
|
||||
/*
|
||||
* Smack Audit hooks
|
||||
*
|
||||
* Audit requires a unique representation of each Smack specific
|
||||
* rule. This unique representation is used to distinguish the
|
||||
* object to be audited from remaining kernel objects and also
|
||||
* works as a glue between the audit hooks.
|
||||
*
|
||||
* Since repository entries are added but never deleted, we'll use
|
||||
* the smack_known label address related to the given audit rule as
|
||||
* the needed unique representation. This also better fits the smack
|
||||
* model where nearly everything is a label.
|
||||
*/
|
||||
#ifdef CONFIG_AUDIT
|
||||
|
||||
/**
|
||||
* smack_audit_rule_init - Initialize a smack audit rule
|
||||
* @field: audit rule fields given from user-space (audit.h)
|
||||
* @op: required testing operator (=, !=, >, <, ...)
|
||||
* @rulestr: smack label to be audited
|
||||
* @vrule: pointer to save our own audit rule representation
|
||||
*
|
||||
* Prepare to audit cases where (@field @op @rulestr) is true.
|
||||
* The label to be audited is created if necessay.
|
||||
*/
|
||||
static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
|
||||
{
|
||||
char **rule = (char **)vrule;
|
||||
*rule = NULL;
|
||||
|
||||
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
|
||||
return -EINVAL;
|
||||
|
||||
if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
|
||||
return -EINVAL;
|
||||
|
||||
*rule = smk_import(rulestr, 0);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* smack_audit_rule_known - Distinguish Smack audit rules
|
||||
* @krule: rule of interest, in Audit kernel representation format
|
||||
*
|
||||
* This is used to filter Smack rules from remaining Audit ones.
|
||||
* If it's proved that this rule belongs to us, the
|
||||
* audit_rule_match hook will be called to do the final judgement.
|
||||
*/
|
||||
static int smack_audit_rule_known(struct audit_krule *krule)
|
||||
{
|
||||
struct audit_field *f;
|
||||
int i;
|
||||
|
||||
for (i = 0; i < krule->field_count; i++) {
|
||||
f = &krule->fields[i];
|
||||
|
||||
if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
|
||||
return 1;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* smack_audit_rule_match - Audit given object ?
|
||||
* @secid: security id for identifying the object to test
|
||||
* @field: audit rule flags given from user-space
|
||||
* @op: required testing operator
|
||||
* @vrule: smack internal rule presentation
|
||||
* @actx: audit context associated with the check
|
||||
*
|
||||
* The core Audit hook. It's used to take the decision of
|
||||
* whether to audit or not to audit a given object.
|
||||
*/
|
||||
static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
|
||||
struct audit_context *actx)
|
||||
{
|
||||
char *smack;
|
||||
char *rule = vrule;
|
||||
|
||||
if (!rule) {
|
||||
audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
|
||||
"Smack: missing rule\n");
|
||||
return -ENOENT;
|
||||
}
|
||||
|
||||
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
|
||||
return 0;
|
||||
|
||||
smack = smack_from_secid(secid);
|
||||
|
||||
/*
|
||||
* No need to do string comparisons. If a match occurs,
|
||||
* both pointers will point to the same smack_known
|
||||
* label.
|
||||
*/
|
||||
if (op == AUDIT_EQUAL)
|
||||
return (rule == smack);
|
||||
if (op == AUDIT_NOT_EQUAL)
|
||||
return (rule != smack);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* smack_audit_rule_free - free smack rule representation
|
||||
* @vrule: rule to be freed.
|
||||
*
|
||||
* No memory was allocated.
|
||||
*/
|
||||
static void smack_audit_rule_free(void *vrule)
|
||||
{
|
||||
/* No-op */
|
||||
}
|
||||
|
||||
#endif /* CONFIG_AUDIT */
|
||||
|
||||
/*
|
||||
* smack_secid_to_secctx - return the smack label for a secid
|
||||
* @secid: incoming integer
|
||||
|
|
@ -2467,6 +2610,7 @@ struct security_operations smack_ops = {
|
|||
.inode_getsecurity = smack_inode_getsecurity,
|
||||
.inode_setsecurity = smack_inode_setsecurity,
|
||||
.inode_listsecurity = smack_inode_listsecurity,
|
||||
.inode_getsecid = smack_inode_getsecid,
|
||||
|
||||
.file_permission = smack_file_permission,
|
||||
.file_alloc_security = smack_file_alloc_security,
|
||||
|
|
@ -2498,6 +2642,7 @@ struct security_operations smack_ops = {
|
|||
.task_prctl = cap_task_prctl,
|
||||
|
||||
.ipc_permission = smack_ipc_permission,
|
||||
.ipc_getsecid = smack_ipc_getsecid,
|
||||
|
||||
.msg_msg_alloc_security = smack_msg_msg_alloc_security,
|
||||
.msg_msg_free_security = smack_msg_msg_free_security,
|
||||
|
|
@ -2542,12 +2687,22 @@ struct security_operations smack_ops = {
|
|||
.sk_free_security = smack_sk_free_security,
|
||||
.sock_graft = smack_sock_graft,
|
||||
.inet_conn_request = smack_inet_conn_request,
|
||||
|
||||
/* key management security hooks */
|
||||
#ifdef CONFIG_KEYS
|
||||
.key_alloc = smack_key_alloc,
|
||||
.key_free = smack_key_free,
|
||||
.key_permission = smack_key_permission,
|
||||
#endif /* CONFIG_KEYS */
|
||||
|
||||
/* Audit hooks */
|
||||
#ifdef CONFIG_AUDIT
|
||||
.audit_rule_init = smack_audit_rule_init,
|
||||
.audit_rule_known = smack_audit_rule_known,
|
||||
.audit_rule_match = smack_audit_rule_match,
|
||||
.audit_rule_free = smack_audit_rule_free,
|
||||
#endif /* CONFIG_AUDIT */
|
||||
|
||||
.secid_to_secctx = smack_secid_to_secctx,
|
||||
.secctx_to_secid = smack_secctx_to_secid,
|
||||
.release_secctx = smack_release_secctx,
|
||||
|
|
|
|||
Loading…
Reference in New Issue