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Commit 4259fa01 authored by Al Viro's avatar Al Viro
Browse files

[PATCH] get rid of AVC_PATH postponed treatment 



        Selinux folks had been complaining about the lack of AVC_PATH
records when audit is disabled.  I must admit my stupidity - I assumed
that avc_audit() really couldn't use audit_log_d_path() because of
deadlocks (== could be called with dcache_lock or vfsmount_lock held).
Shouldn't have made that assumption - it never gets called that way.
It _is_ called under spinlocks, but not those.

        Since audit_log_d_path() uses ab->gfp_mask for allocations,
kmalloc() in there is not a problem.  IOW, the simple fix is sufficient:
let's rip AUDIT_AVC_PATH out and simply generate pathname as part of main
record.  It's trivial to do.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Acked-by: default avatarJames Morris <jmorris@namei.org>
parent 74f2345b

include/linux/audit.h

+0 −2
Original line number Diff line number Diff line
@@ -411,7 +411,6 @@ extern int audit_bprm(struct linux_binprm *bprm); 
extern int audit_socketcall(int nargs, unsigned long *args);

extern int audit_sockaddr(int len, void *addr);

extern int __audit_fd_pair(int fd1, int fd2);

extern int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt);

extern int audit_set_macxattr(const char *name);

extern int __audit_mq_open(int oflag, mode_t mode, struct mq_attr __user *u_attr);

extern int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_prio, const struct timespec __user *u_abs_timeout);
@@ -491,7 +490,6 @@ extern int audit_signals; 
#define audit_socketcall(n,a) ({ 0; })

#define audit_fd_pair(n,a) ({ 0; })

#define audit_sockaddr(len, addr) ({ 0; })

#define audit_avc_path(dentry, mnt) ({ 0; })

#define audit_set_macxattr(n) do { ; } while (0)

#define audit_mq_open(o,m,a) ({ 0; })

#define audit_mq_timedsend(d,l,p,t) ({ 0; })

kernel/auditsc.c

+0 −47
Original line number Diff line number Diff line
@@ -173,12 +173,6 @@ struct audit_aux_data_fd_pair { 
	int	fd[2];

};



struct audit_aux_data_path {

	struct audit_aux_data	d;

	struct dentry		*dentry;

	struct vfsmount		*mnt;

};



struct audit_aux_data_pids {

	struct audit_aux_data	d;

	pid_t			target_pid[AUDIT_AUX_PIDS];
@@ -654,12 +648,6 @@ static inline void audit_free_aux(struct audit_context *context) 
	struct audit_aux_data *aux;



	while ((aux = context->aux)) {

		if (aux->type == AUDIT_AVC_PATH) {

			struct audit_aux_data_path *axi = (void *)aux;

			dput(axi->dentry);

			mntput(axi->mnt);

		}



		context->aux = aux->next;

		kfree(aux);

	}
@@ -1038,11 +1026,6 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts 
			audit_log_hex(ab, axs->a, axs->len);

			break; }



		case AUDIT_AVC_PATH: {

			struct audit_aux_data_path *axi = (void *)aux;

			audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);

			break; }



		case AUDIT_FD_PAIR: {

			struct audit_aux_data_fd_pair *axs = (void *)aux;

			audit_log_format(ab, "fd0=%d fd1=%d", axs->fd[0], axs->fd[1]);
@@ -1990,36 +1973,6 @@ void __audit_ptrace(struct task_struct *t) 
	selinux_get_task_sid(t, &context->target_sid);

}



/**

 * audit_avc_path - record the granting or denial of permissions

 * @dentry: dentry to record

 * @mnt: mnt to record

 *

 * Returns 0 for success or NULL context or < 0 on error.

 *

 * Called from security/selinux/avc.c::avc_audit()

 */

int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)

{

	struct audit_aux_data_path *ax;

	struct audit_context *context = current->audit_context;



	if (likely(!context))

		return 0;



	ax = kmalloc(sizeof(*ax), GFP_ATOMIC);

	if (!ax)

		return -ENOMEM;



	ax->dentry = dget(dentry);

	ax->mnt = mntget(mnt);



	ax->d.type = AUDIT_AVC_PATH;

	ax->d.next = context->aux;

	context->aux = (void *)ax;

	return 0;

}



/**

 * audit_signal_info - record signal info for shutting down audit subsystem

 * @sig: signal value

security/selinux/avc.c

+8 −7
Original line number Diff line number Diff line
@@ -570,10 +570,12 @@ void avc_audit(u32 ssid, u32 tsid, 
		case AVC_AUDIT_DATA_FS:

			if (a->u.fs.dentry) {

				struct dentry *dentry = a->u.fs.dentry;

				if (a->u.fs.mnt)

					audit_avc_path(dentry, a->u.fs.mnt);

				if (a->u.fs.mnt) {

					audit_log_d_path(ab, "path=", dentry, a->u.fs.mnt);

				} else {

					audit_log_format(ab, " name=");

					audit_log_untrustedstring(ab, dentry->d_name.name);

				}

				inode = dentry->d_inode;

			} else if (a->u.fs.inode) {

				struct dentry *dentry;
@@ -624,9 +626,8 @@ void avc_audit(u32 ssid, u32 tsid, 
				case AF_UNIX:

					u = unix_sk(sk);

					if (u->dentry) {

						audit_avc_path(u->dentry, u->mnt);

						audit_log_format(ab, " name=");

						audit_log_untrustedstring(ab, u->dentry->d_name.name);

						audit_log_d_path(ab, "path=",

								 u->dentry, u->mnt);

						break;

					}

					if (!u->addr)