net/packet: fix overflow in check for tp_frame_nr

[pandora-kernel.git] / net / packet / af_packet.c

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index d60ca88..92d57aa 100644 (file)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -195,6 +195,7 @@ struct tpacket_kbdq_core {
        char            *pkblk_start;
        char            *pkblk_end;
        int             kblk_size;
+       unsigned int    max_frame_len;
        unsigned int    knum_blocks;
        uint64_t        knxt_seq_num;
        char            *prev;
@@ -616,6 +617,7 @@ static void init_prb_bdqc(struct packet_sock *po,
        p1->tov_in_jiffies = msecs_to_jiffies(p1->retire_blk_tov);
        p1->blk_sizeof_priv = req_u->req3.tp_sizeof_priv;
 
+       p1->max_frame_len = p1->kblk_size - BLK_PLUS_PRIV(p1->blk_sizeof_priv);
        prb_init_ft_ops(p1, req_u);
        prb_setup_retire_blk_timer(po, tx_ring);
        prb_open_block(p1, pbd);
@@ -1775,6 +1777,18 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev,
                        if ((int)snaplen < 0)
                                snaplen = 0;
                }
+       } else if (unlikely(macoff + snaplen >
+                           GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len)) {
+               u32 nval;
+
+               nval = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len - macoff;
+               pr_err_once("tpacket_rcv: packet too big, clamped from %u to %u. macoff=%u\n",
+                           snaplen, nval, macoff);
+               snaplen = nval;
+               if (unlikely((int)snaplen < 0)) {
+                       snaplen = 0;
+                       macoff = GET_PBDQC_FROM_RB(&po->rx_ring)->max_frame_len;
+               }
        }
        spin_lock(&sk->sk_receive_queue.lock);
        h.raw = packet_current_rx_frame(po, skb,
@@ -3622,6 +3636,10 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
                        goto out;
                if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
                        goto out;
+               if (po->tp_version >= TPACKET_V3 &&
+                   req->tp_block_size <=
+                         BLK_PLUS_PRIV((u64)req_u->req3.tp_sizeof_priv))
+                       goto out;
                if (unlikely(req->tp_frame_size < po->tp_hdrlen +
                                        po->tp_reserve))
                        goto out;
@@ -3631,6 +3649,8 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
                rb->frames_per_block = req->tp_block_size/req->tp_frame_size;
                if (unlikely(rb->frames_per_block <= 0))
                        goto out;
+               if (unlikely(req->tp_block_size > UINT_MAX / req->tp_block_nr))
+                       goto out;
                if (unlikely((rb->frames_per_block * req->tp_block_nr) !=
                                        req->tp_frame_nr))
                        goto out;