A problem was found while reviewing the code after Bugzilla bug http://bugzilla.kernel.org/show_bug.cgi?id=11796. In ipc_addid(), the newly allocated ipc structure is inserted into the ipcs tree (i.e made visible to readers) without locking it. This is not correct since its initialization continues after it has been inserted in the tree. This patch moves the ipc structure lock initialization + locking before the actual insertion. Regards, Nadia Signed-off-by: Nadia Derbey --- ipc/util.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) Index: linux-2.6.27/ipc/util.c =================================================================== --- linux-2.6.27.orig/ipc/util.c 2008-10-23 15:20:46.000000000 +0200 +++ linux-2.6.27/ipc/util.c 2008-10-28 16:52:17.000000000 +0100 @@ -266,9 +266,17 @@ int ipc_addid(struct ipc_ids* ids, struc if (ids->in_use >= size) return -ENOSPC; + spin_lock_init(&new->lock); + new->deleted = 0; + rcu_read_lock(); + spin_lock(&new->lock); + err = idr_get_new(&ids->ipcs_idr, new, &id); - if (err) + if (err) { + spin_unlock(&new->lock); + rcu_read_unlock(); return err; + } ids->in_use++; @@ -280,10 +288,6 @@ int ipc_addid(struct ipc_ids* ids, struc ids->seq = 0; new->id = ipc_buildid(id, new->seq); - spin_lock_init(&new->lock); - new->deleted = 0; - rcu_read_lock(); - spin_lock(&new->lock); return id; } -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/