diff options
| -rw-r--r-- | ipc/util.c | 31 | ||||
| -rw-r--r-- | ipc/util.h | 3 |
2 files changed, 29 insertions, 5 deletions
diff --git a/ipc/util.c b/ipc/util.c index 813804ebdeb..3df0af3158a 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -824,11 +824,28 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns, struct ipc64_perm *perm, int extra_perm) { struct kern_ipc_perm *ipcp; + + ipcp = ipcctl_pre_down_nolock(ns, ids, id, cmd, perm, extra_perm); + if (IS_ERR(ipcp)) + goto out; + + spin_lock(&ipcp->lock); +out: + return ipcp; +} + +struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns, + struct ipc_ids *ids, int id, int cmd, + struct ipc64_perm *perm, int extra_perm) +{ kuid_t euid; - int err; + int err = -EPERM; + struct kern_ipc_perm *ipcp; down_write(&ids->rw_mutex); - ipcp = ipc_lock_check(ids, id); + rcu_read_lock(); + + ipcp = ipc_obtain_object_check(ids, id); if (IS_ERR(ipcp)) { err = PTR_ERR(ipcp); goto out_up; @@ -837,17 +854,21 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns, audit_ipc_obj(ipcp); if (cmd == IPC_SET) audit_ipc_set_perm(extra_perm, perm->uid, - perm->gid, perm->mode); + perm->gid, perm->mode); euid = current_euid(); if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) || ns_capable(ns->user_ns, CAP_SYS_ADMIN)) return ipcp; - err = -EPERM; - ipc_unlock(ipcp); out_up: + /* + * Unsuccessful lookup, unlock and return + * the corresponding error. + */ + rcu_read_unlock(); up_write(&ids->rw_mutex); + return ERR_PTR(err); } diff --git a/ipc/util.h b/ipc/util.h index bfc8d4ea6e4..13d92fea15a 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -128,6 +128,9 @@ struct kern_ipc_perm *ipc_obtain_object(struct ipc_ids *ids, int id); 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); int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out); +struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns, + struct ipc_ids *ids, int id, int cmd, + struct ipc64_perm *perm, int extra_perm); 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); |