linux/net/core, branch v2.6.35

net: dev_forward_skb should call nf_reset

2010-07-26T04:58:46Z

With conn-track zones and probably with different network namespaces, the netfilter logic needs to be re-calculated on packet receive. If the netfilter logic is not reset, it will not be recalculated properly. This patch adds the nf_reset logic to dev_forward_skb. Signed-off-by: Ben Greear Signed-off-by: David S. Miller

net: Fix skb_copy_expand() handling of ->csum_start

2010-07-22T20:27:09Z

It should only be adjusted if ip_summed == CHECKSUM_PARTIAL. Signed-off-by: David S. Miller

net: Fix corruption of skb csum field in pskb_expand_head() of net/core/skbuff.c

2010-07-22T20:25:18Z

Make pskb_expand_head() check ip_summed to make sure csum_start is really csum_start and not csum before adjusting it. This fixes a bug I encountered using a Sun Quad-Fast Ethernet card and VLANs. On my configuration, the sunhme driver produces skbs with differing amounts of headroom on receive depending on the packet size. See line 2030 of drivers/net/sunhme.c; packets smaller than RX_COPY_THRESHOLD have 52 bytes of headroom but packets larger than that cutoff have only 20 bytes. When these packets reach the VLAN driver, vlan_check_reorder_header() calls skb_cow(), which, if the packet has less than NET_SKB_PAD (== 32) bytes of headroom, uses pskb_expand_head() to make more. Then, pskb_expand_head() needs to adjust a lot of offsets into the skb, including csum_start. Since csum_start is a union with csum, if the packet has a valid csum value this will corrupt it, which was the effect I observed. The sunhme hardware computes receive checksums, so the skbs would be created by the driver with ip_summed == CHECKSUM_COMPLETE and a valid csum field, and then pskb_expand_head() would corrupt the csum field, leading to an "hw csum error" message later on, for example in icmp_rcv() for pings larger than the sunhme RX_COPY_THRESHOLD. On the basis of the comment at the beginning of include/linux/skbuff.h, I believe that the csum_start skb field is only meaningful if ip_csummed is CSUM_PARTIAL, so this patch makes pskb_expand_head() adjust it only in that case to avoid corrupting a valid csum value. Please see my more in-depth disucssion of tracking down this bug for more details if you like: http://puellavulnerata.livejournal.com/112186.html http://puellavulnerata.livejournal.com/112567.html http://puellavulnerata.livejournal.com/112891.html http://puellavulnerata.livejournal.com/113096.html http://puellavulnerata.livejournal.com/113591.html I am not subscribed to this list, so please CC me on replies. Signed-off-by: Andrea Shepard Signed-off-by: David S. Miller

net: fix problem in reading sock TX queue

2010-07-15T03:50:29Z

Fix problem in reading the tx_queue recorded in a socket. In dev_pick_tx, the TX queue is read by doing a check with sk_tx_queue_recorded on the socket, followed by a sk_tx_queue_get. The problem is that there is not mutual exclusion across these calls in the socket so it it is possible that the queue in the sock can be invalidated after sk_tx_queue_recorded is called so that sk_tx_queue get returns -1, which sets 65535 in queue_index and thus dev_pick_tx returns 65536 which is a bogus queue and can cause crash in dev_queue_xmit. We fix this by only calling sk_tx_queue_get which does the proper checks. The interface is that sk_tx_queue_get returns the TX queue if the sock argument is non-NULL and TX queue is recorded, else it returns -1. sk_tx_queue_recorded is no longer used so it can be completely removed. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller

net/core: neighbour update Oops

2010-07-15T01:02:16Z

When configuring DMVPN (GRE + openNHRP) and a GRE remote address is configured a kernel Oops is observed. The obserseved Oops is caused by a NULL header_ops pointer (neigh->dev->header_ops) in neigh_update_hhs() when void (*update)(struct hh_cache*, const struct net_device*, const unsigned char *) = neigh->dev->header_ops->cache_update; is executed. The dev associated with the NULL header_ops is the GRE interface. This patch guards against the possibility that header_ops is NULL. This Oops was first observed in kernel version 2.6.26.8. Signed-off-by: Doug Kehn Acked-by: Eric Dumazet Signed-off-by: David S. Miller

net: skb_tx_hash() fix relative to skb_orphan_try()

2010-07-14T22:33:27Z

commit fc6055a5ba31e2 (net: Introduce skb_orphan_try()) added early orphaning of skbs. This unfortunately added a performance regression in skb_tx_hash() in case of stacked devices (bonding, vlans, ...) Since skb->sk is now NULL, we cannot access sk->sk_hash anymore to spread tx packets to multiple NIC queues on multiqueue devices. skb_tx_hash() in this case only uses skb->protocol, same value for all flows. skb_orphan_try() can copy sk->sk_hash into skb->rxhash and skb_tx_hash() can use this saved sk_hash value to compute its internal hash value. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net: decreasing real_num_tx_queues needs to flush qdisc

2010-07-03T04:59:07Z

Reducing real_num_queues needs to flush the qdisc otherwise skbs with queue_mappings greater then real_num_tx_queues can be sent to the underlying driver. The flow for this is, dev_queue_xmit() dev_pick_tx() skb_tx_hash() => hash using real_num_tx_queues skb_set_queue_mapping() ... qdisc_enqueue_root() => enqueue skb on txq from hash ... dev->real_num_tx_queues -= n ... sch_direct_xmit() dev_hard_start_xmit() ndo_start_xmit(skb,dev) => skb queue set with old hash skbs are enqueued on the qdisc with skb->queue_mapping set 0 < queue_mappings < real_num_tx_queues. When the driver decreases real_num_tx_queues skb's may be dequeued from the qdisc with a queue_mapping greater then real_num_tx_queues. This fixes a case in ixgbe where this was occurring with DCB and FCoE. Because the driver is using queue_mapping to map skbs to tx descriptor rings we can potentially map skbs to rings that no longer exist. Signed-off-by: John Fastabend Tested-by: Ross Brattain Signed-off-by: Jeff Kirsher Signed-off-by: David S. Miller

ethtool: Fix potential user buffer overflow for ETHTOOL_{G, S}RXFH

2010-06-29T08:00:29Z

struct ethtool_rxnfc was originally defined in 2.6.27 for the ETHTOOL_{G,S}RXFH command with only the cmd, flow_type and data fields. It was then extended in 2.6.30 to support various additional commands. These commands should have been defined to use a new structure, but it is too late to change that now. Since user-space may still be using the old structure definition for the ETHTOOL_{G,S}RXFH commands, and since they do not need the additional fields, only copy the originally defined fields to and from user-space. Signed-off-by: Ben Hutchings Cc: stable@kernel.org Signed-off-by: David S. Miller

ethtool: Fix potential kernel buffer overflow in ETHTOOL_GRXCLSRLALL

2010-06-29T08:00:29Z

On a 32-bit machine, info.rule_cnt >= 0x40000000 leads to integer overflow and the buffer may be smaller than needed. Since ETHTOOL_GRXCLSRLALL is unprivileged, this can presumably be used for at least denial of service. Signed-off-by: Ben Hutchings Cc: stable@kernel.org Signed-off-by: David S. Miller

net: rxhash already set in __copy_skb_header

2010-06-14T00:16:54Z

No need to copy rxhash again in __skb_clone() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller