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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>
  • Loading branch information...
commit 1efdb69b0bb41dec8ee3e2cac0a0f167837d0919 1 parent 9582d90
@ebiederm ebiederm authored
View
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;
View
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
View
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 @@ SYSCALL_DEFINE5(msgrcv, int, msqid, struct msgbuf __user *, msgp, size_t, msgsz,
#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);
View
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);
}
View
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,
View
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;
View
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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