[PATCH 4.9 100/148] bnx2x: fix possible overrun of VFPF multicast addresses array

Greg Kroah-Hartman
2017-12-12T12:59:27Z

From: Michal Schmidt <mschmidt@redhat.com>

[ Upstream commit 22118d861cec5da6ed525aaf12a3de9bfeffc58f ]

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 <mschmidt@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)

--- 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_devi
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_devi
/* 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_devi
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_devi
out:
bnx2x_vfpf_finalize(bp, &req->first_tlv);

- return 0;
+ return rc;
}

/* request pf to add a vlan for the vf */