Commit 02276bda authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

audit: Use current instead of NETLINK_CREDS() in audit_filter 



Get caller process uid and gid and pid values from the current task
instead of the NETLINK_CB.  This is simpler than passing NETLINK_CREDS
from from audit_receive_msg to audit_filter_user_rules and avoid the
chance of being hit by the occassional bugs in netlink uid/gid
credential passing.  This is a safe changes because all netlink
requests are processed in the task of the sending process.

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent 34e36d8e

include/linux/audit.h

+1 −1
Original line number Diff line number Diff line
@@ -700,7 +700,7 @@ extern void audit_log_secctx(struct audit_buffer *ab, u32 secid); 
extern int		    audit_update_lsm_rules(void);



				/* Private API (for audit.c only) */

extern int audit_filter_user(struct netlink_skb_parms *cb);

extern int audit_filter_user(void);

extern int audit_filter_type(int type);

extern int  audit_receive_filter(int type, int pid, int uid, int seq,

				void *data, size_t datasz, uid_t loginuid,

kernel/audit.c

+1 −1
Original line number Diff line number Diff line
@@ -744,7 +744,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 
		if (!audit_enabled && msg_type != AUDIT_USER_AVC)

			return 0;



		err = audit_filter_user(&NETLINK_CB(skb));

		err = audit_filter_user();

		if (err == 1) {

			err = 0;

			if (msg_type == AUDIT_USER_TTY) {

kernel/auditfilter.c

+6 −7
Original line number Diff line number Diff line
@@ -1236,8 +1236,7 @@ int audit_compare_dname_path(const char *dname, const char *path, 
	return strncmp(p, dname, dlen);

}



static int audit_filter_user_rules(struct netlink_skb_parms *cb,

				   struct audit_krule *rule,

static int audit_filter_user_rules(struct audit_krule *rule,

				   enum audit_state *state)

{

	int i;
@@ -1249,13 +1248,13 @@ static int audit_filter_user_rules(struct netlink_skb_parms *cb, 


		switch (f->type) {

		case AUDIT_PID:

			result = audit_comparator(cb->creds.pid, f->op, f->val);

			result = audit_comparator(task_pid_vnr(current), f->op, f->val);

			break;

		case AUDIT_UID:

			result = audit_comparator(cb->creds.uid, f->op, f->val);

			result = audit_comparator(current_uid(), f->op, f->val);

			break;

		case AUDIT_GID:

			result = audit_comparator(cb->creds.gid, f->op, f->val);

			result = audit_comparator(current_gid(), f->op, f->val);

			break;

		case AUDIT_LOGINUID:

			result = audit_comparator(audit_get_loginuid(current),
@@ -1287,7 +1286,7 @@ static int audit_filter_user_rules(struct netlink_skb_parms *cb, 
	return 1;

}



int audit_filter_user(struct netlink_skb_parms *cb)

int audit_filter_user(void)

{

	enum audit_state state = AUDIT_DISABLED;

	struct audit_entry *e;
@@ -1295,7 +1294,7 @@ int audit_filter_user(struct netlink_skb_parms *cb) 


	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 (audit_filter_user_rules(&e->rule, &state)) {

			if (state == AUDIT_DISABLED)

				ret = 0;

			break;

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