diff options
Diffstat (limited to 'security/smack/smack_lsm.c')
| -rw-r--r-- | security/smack/smack_lsm.c | 178 |
1 files changed, 162 insertions, 16 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 77ec16a3b68..b5c8f923700 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -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" @@ -574,8 +575,8 @@ static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) * * Returns 0 if access is permitted, an error code otherwise */ -static int smack_inode_setxattr(struct dentry *dentry, char *name, - void *value, size_t size, int flags) +static int smack_inode_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) { int rc = 0; @@ -604,8 +605,8 @@ static int smack_inode_setxattr(struct dentry *dentry, char *name, * Set the pointer in the inode blob to the entry found * in the master label list. */ -static void smack_inode_post_setxattr(struct dentry *dentry, char *name, - void *value, size_t size, int flags) +static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags) { struct inode_smack *isp; char *nsp; @@ -641,7 +642,7 @@ static void smack_inode_post_setxattr(struct dentry *dentry, char *name, * * Returns 0 if access is permitted, an error code otherwise */ -static int smack_inode_getxattr(struct dentry *dentry, char *name) +static int smack_inode_getxattr(struct dentry *dentry, const char *name) { return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); } @@ -655,7 +656,7 @@ static int smack_inode_getxattr(struct dentry *dentry, char *name) * * Returns 0 if access is permitted, an error code otherwise */ -static int smack_inode_removexattr(struct dentry *dentry, char *name) +static int smack_inode_removexattr(struct dentry *dentry, const char *name) { int rc = 0; @@ -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 */ @@ -1118,15 +1131,6 @@ static int smack_task_kill(struct task_struct *p, struct siginfo *info, int sig, u32 secid) { /* - * Special cases where signals really ought to go through - * in spite of policy. Stephen Smalley suggests it may - * make sense to change the caller so that it doesn't - * bother with the LSM hook in these cases. - */ - if (info != SEND_SIG_NOINFO && - (is_si_special(info) || SI_FROMKERNEL(info))) - return 0; - /* * Sending a signal requires that the sender * can write the receiver. */ @@ -1805,6 +1809,18 @@ 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 */ /** @@ -2382,6 +2398,124 @@ 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 * @secdata: destination @@ -2406,7 +2540,7 @@ static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) * * Exists for audit and networking code. */ -static int smack_secctx_to_secid(char *secdata, u32 seclen, u32 *secid) +static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) { *secid = smack_to_secid(secdata); return 0; @@ -2467,6 +2601,7 @@ 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 +2633,7 @@ 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 +2678,22 @@ 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, |