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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: Eric W. Biederman <ebiederm@xmission.com>
master
Eric W. Biederman 10 years ago
parent
commit
1efdb69b0b
  1. 9
      include/linux/ipc.h
  2. 1
      init/Kconfig
  3. 14
      ipc/msg.c
  4. 13
      ipc/sem.c
  5. 19
      ipc/shm.c
  6. 35
      ipc/util.c
  7. 2
      ipc/util.h

9
include/linux/ipc.h

@ -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;

1
init/Kconfig

@ -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

14
ipc/msg.c

@ -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);

13
ipc/sem.c

@ -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);
}

19
ipc/shm.c

@ -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,

35
ipc/util.c

@ -249,8 +249,8 @@ int ipc_get_maxid(struct ipc_ids *ids)
int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
{
uid_t euid;
gid_t egid;
kuid_t euid;
kgid_t egid;
int id, err;
if (size > IPCMNI)
@ -606,14 +606,14 @@ void ipc_rcu_putref(void *ptr)
int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
{
uid_t euid = current_euid();
kuid_t euid = current_euid();
int requested_mode, granted_mode;
audit_ipc_obj(ipcp);
requested_mode = (flag >> 6) | (flag >> 3) | flag;
granted_mode = ipcp->mode;
if (euid == ipcp->cuid ||
euid == ipcp->uid)
if (uid_eq(euid, ipcp->cuid) ||
uid_eq(euid, ipcp->uid))
granted_mode >>= 6;
else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
granted_mode >>= 3;
@ -643,10 +643,10 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
void kernel_to_ipc64_perm (struct kern_ipc_perm *in, struct ipc64_perm *out)
{
out->key = in->key;
out->uid = in->uid;
out->gid = in->gid;
out->cuid = in->cuid;
out->cgid = in->cgid;
out->uid = from_kuid_munged(current_user_ns(), in->uid);
out->gid = from_kgid_munged(current_user_ns(), in->gid);
out->cuid = from_kuid_munged(current_user_ns(), in->cuid);
out->cgid = from_kgid_munged(current_user_ns(), in->cgid);
out->mode = in->mode;
out->seq = in->seq;
}
@ -747,12 +747,19 @@ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
* @in: the permission given as input.
* @out: the permission of the ipc to set.
*/
void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
{
out->uid = in->uid;
out->gid = in->gid;
kuid_t uid = make_kuid(current_user_ns(), in->uid);
kgid_t gid = make_kgid(current_user_ns(), in->gid);
if (!uid_valid(uid) || !gid_valid(gid))
return -EINVAL;
out->uid = uid;
out->gid = gid;
out->mode = (out->mode & ~S_IRWXUGO)
| (in->mode & S_IRWXUGO);
return 0;
}
/**
@ -777,7 +784,7 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns,
struct ipc64_perm *perm, int extra_perm)
{
struct kern_ipc_perm *ipcp;
uid_t euid;
kuid_t euid;
int err;
down_write(&ids->rw_mutex);
@ -793,7 +800,7 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns,
perm->gid, perm->mode);
euid = current_euid();
if (euid == ipcp->cuid || euid == ipcp->uid ||
if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) ||
ns_capable(ns->user_ns, CAP_SYS_ADMIN))
return ipcp;

2
ipc/util.h

@ -125,7 +125,7 @@ struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns,
struct ipc_ids *ids, int id, int cmd,
struct ipc64_perm *perm, int extra_perm);

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