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Commit aba35661 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

ipcns: Add a limit on the number of ipc namespaces 



Acked-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent f7af3d1c

include/linux/ipc_namespace.h

+1 −0
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ struct ipc_namespace { 


	/* user_ns which owns the ipc ns */

	struct user_namespace *user_ns;

	struct ucounts *ucounts;



	struct ns_common ns;

};

include/linux/user_namespace.h

+1 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ enum ucount_type { 
	UCOUNT_USER_NAMESPACES,

	UCOUNT_PID_NAMESPACES,

	UCOUNT_UTS_NAMESPACES,

	UCOUNT_IPC_NAMESPACES,

	UCOUNT_COUNTS,

};

ipc/namespace.c

+34 −11
Original line number Diff line number Diff line
@@ -16,39 +16,61 @@ 


#include "util.h"



static struct ucounts *inc_ipc_namespaces(struct user_namespace *ns)

{

	return inc_ucount(ns, current_euid(), UCOUNT_IPC_NAMESPACES);

}



static void dec_ipc_namespaces(struct ucounts *ucounts)

{

	dec_ucount(ucounts, UCOUNT_IPC_NAMESPACES);

}



static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,

					   struct ipc_namespace *old_ns)

{

	struct ipc_namespace *ns;

	struct ucounts *ucounts;

	int err;



	err = -ENFILE;

	ucounts = inc_ipc_namespaces(user_ns);

	if (!ucounts)

		goto fail;



	err = -ENOMEM;

	ns = kmalloc(sizeof(struct ipc_namespace), GFP_KERNEL);

	if (ns == NULL)

		return ERR_PTR(-ENOMEM);

		goto fail_dec;



	err = ns_alloc_inum(&ns->ns);

	if (err) {

		kfree(ns);

		return ERR_PTR(err);

	}

	if (err)

		goto fail_free;

	ns->ns.ops = &ipcns_operations;



	atomic_set(&ns->count, 1);

	ns->user_ns = get_user_ns(user_ns);

	ns->ucounts = ucounts;



	err = mq_init_ns(ns);

	if (err) {

		put_user_ns(ns->user_ns);

		ns_free_inum(&ns->ns);

		kfree(ns);

		return ERR_PTR(err);

	}

	if (err)

		goto fail_put;



	sem_init_ns(ns);

	msg_init_ns(ns);

	shm_init_ns(ns);



	return ns;



fail_put:

	put_user_ns(ns->user_ns);

	ns_free_inum(&ns->ns);

fail_free:

	kfree(ns);

fail_dec:

	dec_ipc_namespaces(ucounts);

fail:

	return ERR_PTR(err);

}



struct ipc_namespace *copy_ipcs(unsigned long flags,
@@ -96,6 +118,7 @@ static void free_ipc_ns(struct ipc_namespace *ns) 
	msg_exit_ns(ns);

	shm_exit_ns(ns);



	dec_ipc_namespaces(ns->ucounts);

	put_user_ns(ns->user_ns);

	ns_free_inum(&ns->ns);

	kfree(ns);

kernel/ucount.c

+1 −0
Original line number Diff line number Diff line
@@ -70,6 +70,7 @@ static struct ctl_table user_table[] = { 
	UCOUNT_ENTRY("max_user_namespaces"),

	UCOUNT_ENTRY("max_pid_namespaces"),

	UCOUNT_ENTRY("max_uts_namespaces"),

	UCOUNT_ENTRY("max_ipc_namespaces"),

	{ }

};

#endif /* CONFIG_SYSCTL */