From: Dennis Dalessandro Date: Tue, 25 Feb 2020 19:54:45 +0000 (-0500) Subject: IB/hfi1, qib: Ensure RCU is locked when accessing list X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=817a68a6584aa08e323c64283fec5ded7be84759;p=linux.git IB/hfi1, qib: Ensure RCU is locked when accessing list 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.com Reviewed-by: Mike Marciniszyn Signed-off-by: Dennis Dalessandro Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/hw/hfi1/verbs.c b/drivers/infiniband/hw/hfi1/verbs.c index 089e201d75500..2f6323ad9c598 100644 --- a/drivers/infiniband/hw/hfi1/verbs.c +++ b/drivers/infiniband/hw/hfi1/verbs.c @@ -515,10 +515,11 @@ static inline void hfi1_handle_packet(struct hfi1_packet *packet, 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)) @@ -527,6 +528,7 @@ static inline void hfi1_handle_packet(struct hfi1_packet *packet, 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. diff --git a/drivers/infiniband/hw/qib/qib_verbs.c b/drivers/infiniband/hw/qib/qib_verbs.c index 33778d451b827..5ef93f8f17a19 100644 --- a/drivers/infiniband/hw/qib/qib_verbs.c +++ b/drivers/infiniband/hw/qib/qib_verbs.c @@ -329,8 +329,10 @@ void qib_ib_rcv(struct qib_ctxtdata *rcd, void *rhdr, void *data, u32 tlen) 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.