From: Dennis Dalessandro dennis.dalessandro@intel.com
commit 817a68a6584aa08e323c64283fec5ded7be84759 upstream.
The packet handling function, specifically the iteration of the qp list for mad packet processing misses locking RCU before running through the list. Not only is this incorrect, but the list_for_each_entry_rcu() call can not be called with a conditional check for lock dependency. Remedy this by invoking the rcu lock and unlock around the critical section.
This brings MAD packet processing in line with what is done for non-MAD packets.
Fixes: 7724105686e7 ("IB/hfi1: add driver files") Link: https://lore.kernel.org/r/20200225195445.140896.41873.stgit@awfm-01.aw.intel... Reviewed-by: Mike Marciniszyn mike.marciniszyn@intel.com Signed-off-by: Dennis Dalessandro dennis.dalessandro@intel.com Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/hw/hfi1/verbs.c | 4 +++- drivers/infiniband/hw/qib/qib_verbs.c | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/infiniband/hw/hfi1/verbs.c +++ b/drivers/infiniband/hw/hfi1/verbs.c @@ -595,10 +595,11 @@ static inline void hfi1_handle_packet(st opa_get_lid(packet->dlid, 9B)); if (!mcast) goto drop; + rcu_read_lock(); list_for_each_entry_rcu(p, &mcast->qp_list, list) { packet->qp = p->qp; if (hfi1_do_pkey_check(packet)) - goto drop; + goto unlock_drop; spin_lock_irqsave(&packet->qp->r_lock, flags); packet_handler = qp_ok(packet); if (likely(packet_handler)) @@ -607,6 +608,7 @@ static inline void hfi1_handle_packet(st ibp->rvp.n_pkt_drops++; spin_unlock_irqrestore(&packet->qp->r_lock, flags); } + rcu_read_unlock(); /* * Notify rvt_multicast_detach() if it is waiting for us * to finish. --- a/drivers/infiniband/hw/qib/qib_verbs.c +++ b/drivers/infiniband/hw/qib/qib_verbs.c @@ -360,8 +360,10 @@ void qib_ib_rcv(struct qib_ctxtdata *rcd if (mcast == NULL) goto drop; this_cpu_inc(ibp->pmastats->n_multicast_rcv); + rcu_read_lock(); list_for_each_entry_rcu(p, &mcast->qp_list, list) qib_qp_rcv(rcd, hdr, 1, data, tlen, p->qp); + rcu_read_unlock(); /* * Notify rvt_multicast_detach() if it is waiting for us * to finish.