2.6.37-stable review patch. If anyone has any objections, please let us know.
------------------ From: Sean Hefty <[email protected]> commit 29963437a48475036353b95ab142bf199adb909e upstream. When processing a SIDR REQ, the ib_cm allocates a new cm_id. The refcount of the cm_id is initialized to 1. However, cm_process_work will decrement the refcount after invoking all callbacks. The result is that the cm_id will end up with refcount set to 0 by the end of the sidr req handler. If a user tries to destroy the cm_id, the destruction will proceed, under the incorrect assumption that no other threads are referencing the cm_id. This can lead to a crash when the cm callback thread tries to access the cm_id. This problem was noticed as part of a larger investigation with kernel crashes in the rdma_cm when running on a real time OS. Signed-off-by: Sean Hefty <[email protected]> Acked-by: Doug Ledford <[email protected]> Signed-off-by: Roland Dreier <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/infiniband/core/cm.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/infiniband/core/cm.c +++ b/drivers/infiniband/core/cm.c @@ -2989,6 +2989,7 @@ static int cm_sidr_req_handler(struct cm goto out; /* No match. */ } atomic_inc(&cur_cm_id_priv->refcount); + atomic_inc(&cm_id_priv->refcount); spin_unlock_irq(&cm.lock); cm_id_priv->id.cm_handler = cur_cm_id_priv->id.cm_handler; _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
