diff options
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/msg.c | 48 | ||||
| -rw-r--r-- | ipc/sem.c | 42 | ||||
| -rw-r--r-- | ipc/shm.c | 42 | ||||
| -rw-r--r-- | ipc/util.c | 51 | ||||
| -rw-r--r-- | ipc/util.h | 2 |
5 files changed, 66 insertions, 119 deletions
@@ -142,21 +142,6 @@ void __init msg_init(void) } /* - * This routine is called in the paths where the rw_mutex is held to protect - * access to the idr tree. - */ -static inline struct msg_queue *msg_lock_check_down(struct ipc_namespace *ns, - int id) -{ - struct kern_ipc_perm *ipcp = ipc_lock_check_down(&msg_ids(ns), id); - - if (IS_ERR(ipcp)) - return (struct msg_queue *)ipcp; - - return container_of(ipcp, struct msg_queue, q_perm); -} - -/* * msg_lock_(check_) routines are called in the paths where the rw_mutex * is not held. */ @@ -437,35 +422,12 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd, return -EFAULT; } - down_write(&msg_ids(ns).rw_mutex); - msq = msg_lock_check_down(ns, msqid); - if (IS_ERR(msq)) { - err = PTR_ERR(msq); - goto out_up; - } - - ipcp = &msq->q_perm; - - err = audit_ipc_obj(ipcp); - if (err) - goto out_unlock; - - if (cmd == IPC_SET) { - err = audit_ipc_set_perm(msqid64.msg_qbytes, - msqid64.msg_perm.uid, - msqid64.msg_perm.gid, - msqid64.msg_perm.mode); - if (err) - goto out_unlock; - } + ipcp = ipcctl_pre_down(&msg_ids(ns), msqid, cmd, + &msqid64.msg_perm, msqid64.msg_qbytes); + if (IS_ERR(ipcp)) + return PTR_ERR(ipcp); - if (current->euid != ipcp->cuid && - current->euid != ipcp->uid && - !capable(CAP_SYS_ADMIN)) { - /* We _could_ check for CAP_CHOWN above, but we don't */ - err = -EPERM; - goto out_unlock; - } + msq = container_of(ipcp, struct msg_queue, q_perm); err = security_msg_queue_msgctl(msq, cmd); if (err) @@ -141,21 +141,6 @@ void __init sem_init (void) } /* - * This routine is called in the paths where the rw_mutex is held to protect - * access to the idr tree. - */ -static inline struct sem_array *sem_lock_check_down(struct ipc_namespace *ns, - int id) -{ - struct kern_ipc_perm *ipcp = ipc_lock_check_down(&sem_ids(ns), id); - - if (IS_ERR(ipcp)) - return (struct sem_array *)ipcp; - - return container_of(ipcp, struct sem_array, sem_perm); -} - -/* * sem_lock_(check_) routines are called in the paths where the rw_mutex * is not held. */ @@ -878,31 +863,12 @@ static int semctl_down(struct ipc_namespace *ns, int semid, if (copy_semid_from_user(&semid64, arg.buf, version)) return -EFAULT; } - down_write(&sem_ids(ns).rw_mutex); - sma = sem_lock_check_down(ns, semid); - if (IS_ERR(sma)) { - err = PTR_ERR(sma); - goto out_up; - } - - ipcp = &sma->sem_perm; - err = audit_ipc_obj(ipcp); - if (err) - goto out_unlock; + ipcp = ipcctl_pre_down(&sem_ids(ns), semid, cmd, &semid64.sem_perm, 0); + if (IS_ERR(ipcp)) + return PTR_ERR(ipcp); - if (cmd == IPC_SET) { - err = audit_ipc_set_perm(0, semid64.sem_perm.uid, - semid64.sem_perm.gid, - semid64.sem_perm.mode); - if (err) - goto out_unlock; - } - if (current->euid != ipcp->cuid && - current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN)) { - err=-EPERM; - goto out_unlock; - } + sma = container_of(ipcp, struct sem_array, sem_perm); err = security_sem_semctl(sma, cmd); if (err) @@ -126,18 +126,6 @@ static inline struct shmid_kernel *shm_lock_down(struct ipc_namespace *ns, return container_of(ipcp, struct shmid_kernel, shm_perm); } -static inline struct shmid_kernel *shm_lock_check_down( - struct ipc_namespace *ns, - int id) -{ - struct kern_ipc_perm *ipcp = ipc_lock_check_down(&shm_ids(ns), id); - - if (IS_ERR(ipcp)) - return (struct shmid_kernel *)ipcp; - - return container_of(ipcp, struct shmid_kernel, shm_perm); -} - /* * shm_lock_(check_) routines are called in the paths where the rw_mutex * is not held. @@ -620,33 +608,11 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, return -EFAULT; } - down_write(&shm_ids(ns).rw_mutex); - shp = shm_lock_check_down(ns, shmid); - if (IS_ERR(shp)) { - err = PTR_ERR(shp); - goto out_up; - } - - ipcp = &shp->shm_perm; - - err = audit_ipc_obj(ipcp); - if (err) - goto out_unlock; - - if (cmd == IPC_SET) { - err = audit_ipc_set_perm(0, shmid64.shm_perm.uid, - shmid64.shm_perm.gid, - shmid64.shm_perm.mode); - if (err) - goto out_unlock; - } + ipcp = ipcctl_pre_down(&shm_ids(ns), shmid, cmd, &shmid64.shm_perm, 0); + if (IS_ERR(ipcp)) + return PTR_ERR(ipcp); - if (current->euid != ipcp->uid && - current->euid != ipcp->cuid && - !capable(CAP_SYS_ADMIN)) { - err = -EPERM; - goto out_unlock; - } + shp = container_of(ipcp, struct shmid_kernel, shm_perm); err = security_shm_shmctl(shp, cmd); if (err) @@ -824,6 +824,57 @@ void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out) | (in->mode & S_IRWXUGO); } +/** + * ipcctl_pre_down - retrieve an ipc and check permissions for some IPC_XXX cmd + * @ids: the table of ids where to look for the ipc + * @id: the id of the ipc to retrieve + * @cmd: the cmd to check + * @perm: the permission to set + * @extra_perm: one extra permission parameter used by msq + * + * This function does some common audit and permissions check for some IPC_XXX + * cmd and is called from semctl_down, shmctl_down and msgctl_down. + * It must be called without any lock held and + * - retrieves the ipc with the given id in the given table. + * - performs some audit and permission check, depending on the given cmd + * - returns the ipc with both ipc and rw_mutex locks held in case of success + * or an err-code without any lock held otherwise. + */ +struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd, + struct ipc64_perm *perm, int extra_perm) +{ + struct kern_ipc_perm *ipcp; + int err; + + down_write(&ids->rw_mutex); + ipcp = ipc_lock_check_down(ids, id); + if (IS_ERR(ipcp)) { + err = PTR_ERR(ipcp); + goto out_up; + } + + err = audit_ipc_obj(ipcp); + if (err) + goto out_unlock; + + if (cmd == IPC_SET) { + err = audit_ipc_set_perm(extra_perm, perm->uid, + perm->gid, perm->mode); + if (err) + goto out_unlock; + } + if (current->euid == ipcp->cuid || + current->euid == ipcp->uid || capable(CAP_SYS_ADMIN)) + return ipcp; + + err = -EPERM; +out_unlock: + ipc_unlock(ipcp); +out_up: + up_write(&ids->rw_mutex); + return ERR_PTR(err); +} + #ifdef __ARCH_WANT_IPC_PARSE_VERSION @@ -113,6 +113,8 @@ 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); +struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd, + struct ipc64_perm *perm, int extra_perm); #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__) /* On IA-64, we always use the "64-bit version" of the IPC structures. */ |
