From 1efdb69b0bb41dec8ee3e2cac0a0f167837d0919 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Tue, 7 Feb 2012 16:54:11 -0800 Subject: 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 --- ipc/msg.c | 14 +++++++++----- ipc/sem.c | 13 ++++++++----- ipc/shm.c | 19 +++++++++++-------- ipc/util.c | 35 +++++++++++++++++++++-------------- ipc/util.h | 2 +- 5 files changed, 50 insertions(+), 33 deletions(-) (limited to 'ipc') diff --git a/ipc/msg.c b/ipc/msg.c index 7385de25788a..a71af5a65abf 100644 --- a/ipc/msg.c +++ b/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); diff --git a/ipc/sem.c b/ipc/sem.c index 5215a81420df..58d31f1c1eb5 100644 --- a/ipc/sem.c +++ b/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); } diff --git a/ipc/shm.c b/ipc/shm.c index 00faa05cf72a..dff40c9f73c9 100644 --- a/ipc/shm.c +++ b/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, diff --git a/ipc/util.c b/ipc/util.c index eb07fd356f27..72fd0785ac94 100644 --- a/ipc/util.c +++ b/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; diff --git a/ipc/util.h b/ipc/util.h index 850ef3e962cb..c8fe2f7631e9 100644 --- a/ipc/util.h +++ b/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); -- cgit v1.2.3