[SCSI] libfcoe: Handle duplicate critical descriptors

As per FC-BB-5 rev 2, section 7.8.6.2, malformed FIP frame shall be
discarded. Drop discovery adv, ELS and CLV's with duplicate critical
descriptors.

[Resending after incorporating Joe's review comments]

Signed-off-by: Bhanu Prakash Gollapudi <bprakash@broadcom.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

diff --git a/drivers/scsi/fcoe/libfcoe.c b/drivers/scsi/fcoe/libfcoe.c
index 27c21ca802b2d36c264b496bae5f9f8faa13331f..db7185c0b9649e3fd2e22dfac11d98f4ec2bf517 100644 (file)
--- a/drivers/scsi/fcoe/libfcoe.c
+++ b/drivers/scsi/fcoe/libfcoe.c
@@ -640,6 +640,7 @@ static int fcoe_ctlr_parse_adv(struct fcoe_ctlr *fip,
        unsigned long t;
        size_t rlen;
        size_t dlen;
+       u32 desc_mask;
 
        memset(fcf, 0, sizeof(*fcf));
        fcf->fka_period = msecs_to_jiffies(FCOE_CTLR_DEF_FKA);
@@ -647,6 +648,12 @@ static int fcoe_ctlr_parse_adv(struct fcoe_ctlr *fip,
        fiph = (struct fip_header *)skb->data;
        fcf->flags = ntohs(fiph->fip_flags);
 
+       /*
+        * mask of required descriptors. validating each one clears its bit.
+        */
+       desc_mask = BIT(FIP_DT_PRI) | BIT(FIP_DT_MAC) | BIT(FIP_DT_NAME) |
+                       BIT(FIP_DT_FAB) | BIT(FIP_DT_FKA);
+
        rlen = ntohs(fiph->fip_dl_len) * 4;
        if (rlen + sizeof(*fiph) > skb->len)
                return -EINVAL;
@@ -656,11 +663,19 @@ static int fcoe_ctlr_parse_adv(struct fcoe_ctlr *fip,
                dlen = desc->fip_dlen * FIP_BPW;
                if (dlen < sizeof(*desc) || dlen > rlen)
                        return -EINVAL;
+               /* Drop Adv if there are duplicate critical descriptors */
+               if ((desc->fip_dtype < 32) &&
+                   !(desc_mask & 1U << desc->fip_dtype)) {
+                       LIBFCOE_FIP_DBG(fip, "Duplicate Critical "
+                                       "Descriptors in FIP adv\n");
+                       return -EINVAL;
+               }
                switch (desc->fip_dtype) {
                case FIP_DT_PRI:
                        if (dlen != sizeof(struct fip_pri_desc))
                                goto len_err;
                        fcf->pri = ((struct fip_pri_desc *)desc)->fd_pri;
+                       desc_mask &= ~BIT(FIP_DT_PRI);
                        break;
                case FIP_DT_MAC:
                        if (dlen != sizeof(struct fip_mac_desc))
@@ -673,12 +688,14 @@ static int fcoe_ctlr_parse_adv(struct fcoe_ctlr *fip,
                                                "in FIP adv\n");
                                return -EINVAL;
                        }
+                       desc_mask &= ~BIT(FIP_DT_MAC);
                        break;
                case FIP_DT_NAME:
                        if (dlen != sizeof(struct fip_wwn_desc))
                                goto len_err;
                        wwn = (struct fip_wwn_desc *)desc;
                        fcf->switch_name = get_unaligned_be64(&wwn->fd_wwn);
+                       desc_mask &= ~BIT(FIP_DT_NAME);
                        break;
                case FIP_DT_FAB:
                        if (dlen != sizeof(struct fip_fab_desc))
@@ -687,6 +704,7 @@ static int fcoe_ctlr_parse_adv(struct fcoe_ctlr *fip,
                        fcf->fabric_name = get_unaligned_be64(&fab->fd_wwn);
                        fcf->vfid = ntohs(fab->fd_vfid);
                        fcf->fc_map = ntoh24(fab->fd_map);
+                       desc_mask &= ~BIT(FIP_DT_FAB);
                        break;
                case FIP_DT_FKA:
                        if (dlen != sizeof(struct fip_fka_desc))
@@ -697,6 +715,7 @@ static int fcoe_ctlr_parse_adv(struct fcoe_ctlr *fip,
                        t = ntohl(fka->fd_fka_period);
                        if (t >= FCOE_CTLR_MIN_FKA)
                                fcf->fka_period = msecs_to_jiffies(t);
+                       desc_mask &= ~BIT(FIP_DT_FKA);
                        break;
                case FIP_DT_MAP_OUI:
                case FIP_DT_FCOE_SIZE:
@@ -719,6 +738,11 @@ static int fcoe_ctlr_parse_adv(struct fcoe_ctlr *fip,
                return -EINVAL;
        if (!fcf->switch_name || !fcf->fabric_name)
                return -EINVAL;
+       if (desc_mask) {
+               LIBFCOE_FIP_DBG(fip, "adv missing descriptors mask %x\n",
+                               desc_mask);
+               return -EINVAL;
+       }
        return 0;
 
 len_err:
@@ -847,6 +871,7 @@ static void fcoe_ctlr_recv_els(struct fcoe_ctlr *fip, struct sk_buff *skb)
        size_t els_len = 0;
        size_t rlen;
        size_t dlen;
+       u32 dupl_desc = 0;
 
        fiph = (struct fip_header *)skb->data;
        sub = fiph->fip_subcode;
@@ -862,6 +887,15 @@ static void fcoe_ctlr_recv_els(struct fcoe_ctlr *fip, struct sk_buff *skb)
                dlen = desc->fip_dlen * FIP_BPW;
                if (dlen < sizeof(*desc) || dlen > rlen)
                        goto drop;
+               /* Drop ELS if there are duplicate critical descriptors */
+               if (desc->fip_dtype < 32) {
+                       if (dupl_desc & 1U << desc->fip_dtype) {
+                               LIBFCOE_FIP_DBG(fip, "Duplicate Critical "
+                                               "Descriptors in FIP ELS\n");
+                               goto drop;
+                       }
+                       dupl_desc |= (1 << desc->fip_dtype);
+               }
                switch (desc->fip_dtype) {
                case FIP_DT_MAC:
                        if (dlen != sizeof(struct fip_mac_desc))
@@ -973,6 +1007,13 @@ static void fcoe_ctlr_recv_clr_vlink(struct fcoe_ctlr *fip,
                dlen = desc->fip_dlen * FIP_BPW;
                if (dlen > rlen)
                        return;
+               /* Drop CVL if there are duplicate critical descriptors */
+               if ((desc->fip_dtype < 32) &&
+                   !(desc_mask & 1U << desc->fip_dtype)) {
+                       LIBFCOE_FIP_DBG(fip, "Duplicate Critical "
+                                       "Descriptors in FIP CVL\n");
+                       return;
+               }
                switch (desc->fip_dtype) {
                case FIP_DT_MAC:
                        mp = (struct fip_mac_desc *)desc;