[PATCH net 3/7] bnx2x: fix possible overrun of VFPF multicast addresses array

[Michal Schmidt]

It is too late to check for the limit of the number of VF multicast
addresses after they have already been copied to the req->multicast[]
array, possibly overflowing it.

Do the check before copying.

Also fix the error path to not skip unlocking vf2pf_mutex.

Signed-off-by: Michal Schmidt <mschm...@redhat.com>
---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c 
b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c
index bfae300cf2..c2d327d9df 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c
@@ -868,7 +868,7 @@ int bnx2x_vfpf_set_mcast(struct net_device *dev)
        struct bnx2x *bp = netdev_priv(dev);
        struct vfpf_set_q_filters_tlv *req = &bp->vf2pf_mbox->req.set_q_filters;
        struct pfvf_general_resp_tlv *resp = &bp->vf2pf_mbox->resp.general_resp;
-       int rc, i = 0;
+       int rc = 0, i = 0;
        struct netdev_hw_addr *ha;
 
        if (bp->state != BNX2X_STATE_OPEN) {
@@ -883,6 +883,15 @@ int bnx2x_vfpf_set_mcast(struct net_device *dev)
        /* Get Rx mode requested */
        DP(NETIF_MSG_IFUP, "dev->flags = %x\n", dev->flags);
 
+       /* We support PFVF_MAX_MULTICAST_PER_VF mcast addresses tops */
+       if (netdev_mc_count(dev) > PFVF_MAX_MULTICAST_PER_VF) {
+               DP(NETIF_MSG_IFUP,
+                  "VF supports not more than %d multicast MAC addresses\n",
+                  PFVF_MAX_MULTICAST_PER_VF);
+               rc = -EINVAL;
+               goto out;
+       }
+
        netdev_for_each_mc_addr(ha, dev) {
                DP(NETIF_MSG_IFUP, "Adding mcast MAC: %pM\n",
                   bnx2x_mc_addr(ha));
@@ -890,16 +899,6 @@ int bnx2x_vfpf_set_mcast(struct net_device *dev)
                i++;
        }
 
-       /* We support four PFVF_MAX_MULTICAST_PER_VF mcast
-         * addresses tops
-         */
-       if (i >= PFVF_MAX_MULTICAST_PER_VF) {
-               DP(NETIF_MSG_IFUP,
-                  "VF supports not more than %d multicast MAC addresses\n",
-                  PFVF_MAX_MULTICAST_PER_VF);
-               return -EINVAL;
-       }
-
        req->n_multicast = i;
        req->flags |= VFPF_SET_Q_FILTERS_MULTICAST_CHANGED;
        req->vf_qid = 0;
@@ -924,7 +923,7 @@ int bnx2x_vfpf_set_mcast(struct net_device *dev)
 out:
        bnx2x_vfpf_finalize(bp, &req->first_tlv);
 
-       return 0;
+       return rc;
 }
 
 /* request pf to add a vlan for the vf */
-- 
2.9.3