Commit 1efdb69b authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

userns: Convert ipc to use kuid and kgid where appropriate 



- Store the ipc owner and creator with a kuid
- Store the ipc group and the crators group with a kgid.
- Add error handling to ipc_update_perms, allowing it to
  fail if the uids and gids can not be converted to kuids
  or kgids.
- Modify the proc files to display the ipc creator and
  owner in the user namespace of the opener of the proc file.

Signed-off-by: default avatarEric W. Biederman <ebiederm@xmission.com>
parent 9582d901

include/linux/ipc.h

+5 −4
Original line number Diff line number Diff line
@@ -79,6 +79,7 @@ struct ipc_kludge { 


#ifdef __KERNEL__

#include <linux/spinlock.h>

#include <linux/uidgid.h>



#define IPCMNI 32768  /* <= MAX_INT limit for ipc arrays (including sysctl changes) */
@@ -89,10 +90,10 @@ struct kern_ipc_perm 
	int		deleted;

	int		id;

	key_t		key;

	uid_t		uid;

	gid_t		gid;

	uid_t		cuid;

	gid_t		cgid;

	kuid_t		uid;

	kgid_t		gid;

	kuid_t		cuid;

	kgid_t		cgid;

	umode_t		mode; 

	unsigned long	seq;

	void		*security;

init/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -925,7 +925,6 @@ config UIDGID_CONVERTED 


	# List of kernel pieces that need user namespace work

	# Features

	depends on SYSVIPC = n

	depends on IMA = n

	depends on EVM = n

	depends on KEYS = n

ipc/msg.c

+9 −5
Original line number Diff line number Diff line
@@ -443,9 +443,12 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd, 
			goto out_unlock;

		}



		err = ipc_update_perm(&msqid64.msg_perm, ipcp);

		if (err)

			goto out_unlock;



		msq->q_qbytes = msqid64.msg_qbytes;



		ipc_update_perm(&msqid64.msg_perm, ipcp);

		msq->q_ctime = get_seconds();

		/* sleeping receivers might be excluded by

		 * stricter permissions.
@@ -922,6 +925,7 @@ out: 
#ifdef CONFIG_PROC_FS

static int sysvipc_msg_proc_show(struct seq_file *s, void *it)

{

	struct user_namespace *user_ns = seq_user_ns(s);

	struct msg_queue *msq = it;



	return seq_printf(s,
@@ -933,10 +937,10 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it) 
			msq->q_qnum,

			msq->q_lspid,

			msq->q_lrpid,

			msq->q_perm.uid,

			msq->q_perm.gid,

			msq->q_perm.cuid,

			msq->q_perm.cgid,

			from_kuid_munged(user_ns, msq->q_perm.uid),

			from_kgid_munged(user_ns, msq->q_perm.gid),

			from_kuid_munged(user_ns, msq->q_perm.cuid),

			from_kgid_munged(user_ns, msq->q_perm.cgid),

			msq->q_stime,

			msq->q_rtime,

			msq->q_ctime);

ipc/sem.c

+8 −5
Original line number Diff line number Diff line
@@ -1104,7 +1104,9 @@ static int semctl_down(struct ipc_namespace *ns, int semid, 
		freeary(ns, ipcp);

		goto out_up;

	case IPC_SET:

		ipc_update_perm(&semid64.sem_perm, ipcp);

		err = ipc_update_perm(&semid64.sem_perm, ipcp);

		if (err)

			goto out_unlock;

		sma->sem_ctime = get_seconds();

		break;

	default:
@@ -1677,6 +1679,7 @@ void exit_sem(struct task_struct *tsk) 
#ifdef CONFIG_PROC_FS

static int sysvipc_sem_proc_show(struct seq_file *s, void *it)

{

	struct user_namespace *user_ns = seq_user_ns(s);

	struct sem_array *sma = it;



	return seq_printf(s,
@@ -1685,10 +1688,10 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it) 
			  sma->sem_perm.id,

			  sma->sem_perm.mode,

			  sma->sem_nsems,

			  sma->sem_perm.uid,

			  sma->sem_perm.gid,

			  sma->sem_perm.cuid,

			  sma->sem_perm.cgid,

			  from_kuid_munged(user_ns, sma->sem_perm.uid),

			  from_kgid_munged(user_ns, sma->sem_perm.gid),

			  from_kuid_munged(user_ns, sma->sem_perm.cuid),

			  from_kgid_munged(user_ns, sma->sem_perm.cgid),

			  sma->sem_otime,

			  sma->sem_ctime);

}

ipc/shm.c

+11 −8
Original line number Diff line number Diff line
@@ -758,7 +758,9 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, 
		do_shm_rmid(ns, ipcp);

		goto out_up;

	case IPC_SET:

		ipc_update_perm(&shmid64.shm_perm, ipcp);

		err = ipc_update_perm(&shmid64.shm_perm, ipcp);

		if (err)

			goto out_unlock;

		shp->shm_ctim = get_seconds();

		break;

	default:
@@ -893,10 +895,10 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int, cmd, struct shmid_ds __user *, buf) 
		audit_ipc_obj(&(shp->shm_perm));



		if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {

			uid_t euid = current_euid();

			kuid_t euid = current_euid();

			err = -EPERM;

			if (euid != shp->shm_perm.uid &&

			    euid != shp->shm_perm.cuid)

			if (!uid_eq(euid, shp->shm_perm.uid) &&

			    !uid_eq(euid, shp->shm_perm.cuid))

				goto out_unlock;

			if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK))

				goto out_unlock;
@@ -1220,6 +1222,7 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr) 
#ifdef CONFIG_PROC_FS

static int sysvipc_shm_proc_show(struct seq_file *s, void *it)

{

	struct user_namespace *user_ns = seq_user_ns(s);

	struct shmid_kernel *shp = it;

	unsigned long rss = 0, swp = 0;
@@ -1242,10 +1245,10 @@ static int sysvipc_shm_proc_show(struct seq_file *s, void *it) 
			  shp->shm_cprid,

			  shp->shm_lprid,

			  shp->shm_nattch,

			  shp->shm_perm.uid,

			  shp->shm_perm.gid,

			  shp->shm_perm.cuid,

			  shp->shm_perm.cgid,

			  from_kuid_munged(user_ns, shp->shm_perm.uid),

			  from_kgid_munged(user_ns, shp->shm_perm.gid),

			  from_kuid_munged(user_ns, shp->shm_perm.cuid),

			  from_kgid_munged(user_ns, shp->shm_perm.cgid),

			  shp->shm_atim,

			  shp->shm_dtim,

			  shp->shm_ctim,

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