From 58c92f1359c6811478159cfe3cc3118bdb995608 Mon Sep 17 00:00:00 2001 From: Martin Blumenstingl Date: Sun, 22 Nov 2015 17:46:09 +0100 Subject: packet: Allow packets with only a header (but no payload) [ Upstream commit 880621c2605b82eb5af91a2c94223df6f5a3fb64 ] Commit 9c7077622dd91 ("packet: make packet_snd fail on len smaller than l2 header") added validation for the packet size in packet_snd. This change enforces that every packet needs a header (with at least hard_header_len bytes) plus a payload with at least one byte. Before this change the payload was optional. This fixes PPPoE connections which do not have a "Service" or "Host-Uniq" configured (which is violating the spec, but is still widely used in real-world setups). Those are currently failing with the following message: "pppd: packet size is too short (24 <= 24)" Signed-off-by: Martin Blumenstingl Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/packet/af_packet.c') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ebc39e66d704..738c8bac0320 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2112,8 +2112,8 @@ static void tpacket_destruct_skb(struct sk_buff *skb) static bool ll_header_truncated(const struct net_device *dev, int len) { /* net device doesn't like empty head */ - if (unlikely(len <= dev->hard_header_len)) { - net_warn_ratelimited("%s: packet size is too short (%d <= %d)\n", + if (unlikely(len < dev->hard_header_len)) { + net_warn_ratelimited("%s: packet size is too short (%d < %d)\n", current->comm, len, dev->hard_header_len); return true; } -- cgit v1.2.3 From 795f5dc952b62c0a4afe5d8872f6f16372243293 Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Wed, 9 Mar 2016 21:58:34 -0500 Subject: packet: validate variable length ll headers [ Upstream commit 9ed988cd591500c040b2a6257bc68543e08ceeef ] Replace link layer header validation check ll_header_truncate with more generic dev_validate_header. Validation based on hard_header_len incorrectly drops valid packets in variable length protocols, such as AX25. dev_validate_header calls header_ops.validate for such protocols to ensure correctness below hard_header_len. See also http://comments.gmane.org/gmane.linux.network/401064 Fixes 9c7077622dd9 ("packet: make packet_snd fail on len smaller than l2 header") Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 37 ++++++++++++++++--------------------- 1 file changed, 16 insertions(+), 21 deletions(-) (limited to 'net/packet/af_packet.c') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 738c8bac0320..68a048472e5f 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1699,6 +1699,10 @@ retry: goto retry; } + if (!dev_validate_header(dev, skb->data, len)) { + err = -EINVAL; + goto out_unlock; + } if (len > (dev->mtu + dev->hard_header_len + extra_len) && !packet_extra_vlan_len_allowed(dev, skb)) { err = -EMSGSIZE; @@ -2109,18 +2113,6 @@ static void tpacket_destruct_skb(struct sk_buff *skb) sock_wfree(skb); } -static bool ll_header_truncated(const struct net_device *dev, int len) -{ - /* net device doesn't like empty head */ - if (unlikely(len < dev->hard_header_len)) { - net_warn_ratelimited("%s: packet size is too short (%d < %d)\n", - current->comm, len, dev->hard_header_len); - return true; - } - - return false; -} - static void tpacket_set_protocol(const struct net_device *dev, struct sk_buff *skb) { @@ -2203,19 +2195,19 @@ static int tpacket_fill_skb(struct packet_sock *po, struct sk_buff *skb, if (unlikely(err < 0)) return -EINVAL; } else if (dev->hard_header_len) { - if (ll_header_truncated(dev, tp_len)) - return -EINVAL; + int hdrlen = min_t(int, dev->hard_header_len, tp_len); skb_push(skb, dev->hard_header_len); - err = skb_store_bits(skb, 0, data, - dev->hard_header_len); + err = skb_store_bits(skb, 0, data, hdrlen); if (unlikely(err)) return err; + if (!dev_validate_header(dev, skb->data, hdrlen)) + return -EINVAL; if (!skb->protocol) tpacket_set_protocol(dev, skb); - data += dev->hard_header_len; - to_write -= dev->hard_header_len; + data += hdrlen; + to_write -= hdrlen; } offset = offset_in_page(data); @@ -2538,9 +2530,6 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) offset = dev_hard_header(skb, dev, ntohs(proto), addr, NULL, len); if (unlikely(offset < 0)) goto out_free; - } else { - if (ll_header_truncated(dev, len)) - goto out_free; } /* Returns -EFAULT on error */ @@ -2548,6 +2537,12 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) if (err) goto out_free; + if (sock->type == SOCK_RAW && + !dev_validate_header(dev, skb->data, len)) { + err = -EINVAL; + goto out_free; + } + sock_tx_timestamp(sk, &skb_shinfo(skb)->tx_flags); if (!gso_type && (len > dev->mtu + reserve + extra_len) && -- cgit v1.2.3 From 4b5223be98e1972e177f319159a29eb3bab2720e Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Sun, 10 Apr 2016 12:52:28 +0200 Subject: packet: fix heap info leak in PACKET_DIAG_MCLIST sock_diag interface [ Upstream commit 309cf37fe2a781279b7675d4bb7173198e532867 ] Because we miss to wipe the remainder of i->addr[] in packet_mc_add(), pdiag_put_mclist() leaks uninitialized heap bytes via the PACKET_DIAG_MCLIST netlink attribute. Fix this by explicitly memset(0)ing the remaining bytes in i->addr[]. Fixes: eea68e2f1a00 ("packet: Report socket mclist info via diag module") Signed-off-by: Mathias Krause Cc: Eric W. Biederman Cc: Pavel Emelyanov Acked-by: Pavel Emelyanov Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/packet/af_packet.c') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 68a048472e5f..a3654d929814 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -3207,6 +3207,7 @@ static int packet_mc_add(struct sock *sk, struct packet_mreq_max *mreq) i->ifindex = mreq->mr_ifindex; i->alen = mreq->mr_alen; memcpy(i->addr, mreq->mr_address, i->alen); + memset(i->addr + i->alen, 0, sizeof(i->addr) - i->alen); i->count = 1; i->next = po->mclist; po->mclist = i; -- cgit v1.2.3