IB/hfi1: Fix ECN processing in prescan_rxq

When processing ECN via the prescan_rxq path, some fields in the packet
structure are passed uninitialized. This can potentially
cause NULL pointer exceptions during ECN handling.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 11 insertions, 9 deletions

diff --git a/drivers/infiniband/hw/hfi1/driver.c b/drivers/infiniband/hw/hfi1/driver.c
index dadd35eedc01..c5efff29c147 100644
--- a/drivers/infiniband/hw/hfi1/driver.c
+++ b/drivers/infiniband/hw/hfi1/driver.c
@@ -599,7 +599,6 @@ static void __prescan_rxq(struct hfi1_packet *packet)
                                          dd->rhf_offset;
                 struct rvt_qp *qp;
                 struct ib_header *hdr;
-                struct ib_other_headers *ohdr;
                 struct rvt_dev_info *rdi = &dd->verbs_dev.rdi;
                 u64 rhf = rhf_to_cpu(rhf_addr);
                 u32 etype = rhf_rcv_type(rhf), qpn, bth1;
@@ -615,18 +614,21 @@ static void __prescan_rxq(struct hfi1_packet *packet)
                 if (etype != RHF_RCV_TYPE_IB)
                         goto next;
 
-                hdr = hfi1_get_msgheader(dd, rhf_addr);
+                packet->hdr = hfi1_get_msgheader(dd, rhf_addr);
+                hdr = packet->hdr;
 
                 lnh = be16_to_cpu(hdr->lrh[0]) & 3;
 
-                if (lnh == HFI1_LRH_BTH)
-                        ohdr = &hdr->u.oth;
-                else if (lnh == HFI1_LRH_GRH)
-                        ohdr = &hdr->u.l.oth;
-                else
+                if (lnh == HFI1_LRH_BTH) {
+                        packet->ohdr = &hdr->u.oth;
+                } else if (lnh == HFI1_LRH_GRH) {
+                        packet->ohdr = &hdr->u.l.oth;
+                        packet->rcv_flags |= HFI1_HAS_GRH;
+                } else {
                         goto next; /* just in case */
+                }
 
-                bth1 = be32_to_cpu(ohdr->bth[1]);
+                bth1 = be32_to_cpu(packet->ohdr->bth[1]);
                 is_ecn = !!(bth1 & (HFI1_FECN_SMASK | HFI1_BECN_SMASK));
 
                 if (!is_ecn)
@@ -646,7 +648,7 @@ static void __prescan_rxq(struct hfi1_packet *packet)
 
                 /* turn off BECN, FECN */
                 bth1 &= ~(HFI1_FECN_SMASK | HFI1_BECN_SMASK);
-                ohdr->bth[1] = cpu_to_be32(bth1);
+                packet->ohdr->bth[1] = cpu_to_be32(bth1);
 next:
                 update_ps_mdata(&mdata, rcd);
         }