diff options
Diffstat (limited to 'ipc/util.c')
| -rw-r--r-- | ipc/util.c | 21 |
1 files changed, 6 insertions, 15 deletions
diff --git a/ipc/util.c b/ipc/util.c index 399821ac0a9a..a0c139f3d1f3 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -746,8 +746,10 @@ int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out) * 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 + * - returns the ipc with the ipc lock held in case of success * or an err-code without any lock held otherwise. + * + * Call holding the both the rw_mutex and the rcu read lock. */ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns, struct ipc_ids *ids, int id, int cmd, @@ -772,13 +774,10 @@ struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns, int err = -EPERM; struct kern_ipc_perm *ipcp; - down_write(&ids->rw_mutex); - rcu_read_lock(); - ipcp = ipc_obtain_object_check(ids, id); if (IS_ERR(ipcp)) { err = PTR_ERR(ipcp); - goto out_up; + goto err; } audit_ipc_obj(ipcp); @@ -789,16 +788,8 @@ struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns, euid = current_euid(); if (uid_eq(euid, ipcp->cuid) || uid_eq(euid, ipcp->uid) || ns_capable(ns->user_ns, CAP_SYS_ADMIN)) - return ipcp; - -out_up: - /* - * Unsuccessful lookup, unlock and return - * the corresponding error. - */ - rcu_read_unlock(); - up_write(&ids->rw_mutex); - + return ipcp; /* successful lookup */ +err: return ERR_PTR(err); } |