3.2.72-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Manfred Spraul <[email protected]> commit e8577d1f0329d4842e8302e289fb2c22156abef4 upstream. ipc_addid() makes a new ipc identifier visible to everyone. New objects start as locked, so that the caller can complete the initialization after the call. Within struct sem_array, at least sma->sem_base and sma->sem_nsems are accessed without any locks, therefore this approach doesn't work. Thus: Move the ipc_addid() to the end of the initialization. Signed-off-by: Manfred Spraul <[email protected]> Reported-by: Rik van Riel <[email protected]> Acked-by: Rik van Riel <[email protected]> Acked-by: Davidlohr Bueso <[email protected]> Acked-by: Rafael Aquini <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]> [bwh: Backported to 3.2: - Adjust context - The error path being moved looks a little different] Signed-off-by: Ben Hutchings <[email protected]> --- --- a/ipc/sem.c +++ b/ipc/sem.c @@ -314,14 +314,6 @@ static int newary(struct ipc_namespace * return retval; } - id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni); - if (id < 0) { - security_sem_free(sma); - ipc_rcu_putref(sma); - return id; - } - ns->used_sems += nsems; - sma->sem_base = (struct sem *) &sma[1]; for (i = 0; i < nsems; i++) @@ -332,6 +324,15 @@ static int newary(struct ipc_namespace * INIT_LIST_HEAD(&sma->list_id); sma->sem_nsems = nsems; sma->sem_ctime = get_seconds(); + + id = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni); + if (id < 0) { + security_sem_free(sma); + ipc_rcu_putref(sma); + return id; + } + ns->used_sems += nsems; + sem_unlock(sma); return sma->sem_perm.id; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
