linux/net/ipv6, branch v4.5

udp6: fix UDP/IPv6 encap resubmit path

2016-03-07T20:23:12Z

IPv4 interprets a negative return value from a protocol handler as a request to redispatch to a new protocol. In contrast, IPv6 interprets a negative value as an error, and interprets a positive value as a request for redispatch. UDP for IPv6 was unaware of this difference. Change __udp6_lib_rcv() to return a positive value for redispatch. Note that the socket's encap_rcv hook still needs to return a negative value to request dispatch, and in the case of IPv6 packets, adjust IP6CB(skb)->nhoff to identify the byte containing the next protocol. Signed-off-by: Bill Sommerfeld Signed-off-by: David S. Miller

ipv6: re-enable fragment header matching in ipv6_find_hdr

2016-03-03T21:35:20Z

When ipv6_find_hdr is used to find a fragment header (caller specifies target NEXTHDR_FRAGMENT) we erronously return -ENOENT for all fragments with nonzero offset. Before commit 9195bb8e381d, when target was specified, we did not enter the exthdr walk loop as nexthdr == target so this used to work. Now we do (so we can skip empty route headers). When we then stumble upon a frag with nonzero frag_off we must return -ENOENT ("header not found") only if the caller did not specifically request NEXTHDR_FRAGMENT. This allows nfables exthdr expression to match ipv6 fragments, e.g. via nft add rule ip6 filter input frag frag-off gt 0 Fixes: 9195bb8e381d ("ipv6: improve ipv6_find_hdr() to skip empty routing headers") Signed-off-by: Florian Westphal Signed-off-by: David S. Miller

mld, igmp: Fix reserved tailroom calculation

2016-03-03T20:41:07Z

The current reserved_tailroom calculation fails to take hlen and tlen into account. skb: [__hlen__|__data____________|__tlen___|__extra__] ^ ^ head skb_end_offset In this representation, hlen + data + tlen is the size passed to alloc_skb. "extra" is the extra space made available in __alloc_skb because of rounding up by kmalloc. We can reorder the representation like so: [__hlen__|__data____________|__extra__|__tlen___] ^ ^ head skb_end_offset The maximum space available for ip headers and payload without fragmentation is min(mtu, data + extra). Therefore, reserved_tailroom = data + extra + tlen - min(mtu, data + extra) = skb_end_offset - hlen - min(mtu, skb_end_offset - hlen - tlen) = skb_tailroom - min(mtu, skb_tailroom - tlen) ; after skb_reserve(hlen) Compare the second line to the current expression: reserved_tailroom = skb_end_offset - min(mtu, skb_end_offset) and we can see that hlen and tlen are not taken into account. The min() in the third line can be expanded into: if mtu < skb_tailroom - tlen: reserved_tailroom = skb_tailroom - mtu else: reserved_tailroom = tlen Depending on hlen, tlen, mtu and the number of multicast address records, the current code may output skbs that have less tailroom than dev->needed_tailroom or it may output more skbs than needed because not all space available is used. Fixes: 4c672e4b ("ipv6: mld: fix add_grhead skb_over_panic for devs with large MTUs") Signed-off-by: Benjamin Poirier Acked-by: Hannes Frederic Sowa Acked-by: Daniel Borkmann Signed-off-by: David S. Miller

tunnel: Clear IPCB(skb)->opt before dst_link_failure called

2016-02-24T00:11:56Z

IPCB may contain data from previous layers (in the observed case the qdisc layer). In the observed scenario, the data was misinterpreted as ip header options, which later caused the ihl to be set to an invalid value (<5). This resulted in an infinite loop in the mips implementation of ip_fast_csum. This patch clears IPCB(skb)->opt before dst_link_failure can be called for various types of tunnels. This change only applies to encapsulated ipv4 packets. The code introduced in 11c21a30 which clears all of IPCB has been removed to be consistent with these changes, and instead the opt field is cleared unconditionally in ip_tunnel_xmit. The change in ip_tunnel_xmit applies to SIT, GRE, and IPIP tunnels. The relevant vti, l2tp, and pptp functions already contain similar code for clearing the IPCB. Signed-off-by: Bernie Harris Signed-off-by: David S. Miller

rtnl: RTM_GETNETCONF: fix wrong return value

2016-02-19T20:33:46Z

An error response from a RTM_GETNETCONF request can return the positive error value EINVAL in the struct nlmsgerr that can mislead userspace. Signed-off-by: Anton Protopopov Acked-by: Cong Wang Signed-off-by: David S. Miller

gre: clear IFF_TX_SKB_SHARING

2016-02-18T19:43:48Z

ether_setup sets IFF_TX_SKB_SHARING but this is not supported by gre as it modifies the skb on xmit. Also, clean up whitespace in ipgre_tap_setup when we're already touching it. Signed-off-by: Jiri Benc Signed-off-by: David S. Miller

tcp/dccp: fix another race at listener dismantle

2016-02-18T16:35:51Z

Ilya reported following lockdep splat: kernel: ========================= kernel: [ BUG: held lock freed! ] kernel: 4.5.0-rc1-ceph-00026-g5e0a311 #1 Not tainted kernel: ------------------------- kernel: swapper/5/0 is freeing memory ffff880035c9d200-ffff880035c9dbff, with a lock still held there! kernel: (&(&queue->rskq_lock)->rlock){+.-...}, at: [] inet_csk_reqsk_queue_add+0x28/0xa0 kernel: 4 locks held by swapper/5/0: kernel: #0: (rcu_read_lock){......}, at: [] netif_receive_skb_internal+0x4b/0x1f0 kernel: #1: (rcu_read_lock){......}, at: [] ip_local_deliver_finish+0x3f/0x380 kernel: #2: (slock-AF_INET){+.-...}, at: [] sk_clone_lock+0x19b/0x440 kernel: #3: (&(&queue->rskq_lock)->rlock){+.-...}, at: [] inet_csk_reqsk_queue_add+0x28/0xa0 To properly fix this issue, inet_csk_reqsk_queue_add() needs to return to its callers if the child as been queued into accept queue. We also need to make sure listener is still there before calling sk->sk_data_ready(), by holding a reference on it, since the reference carried by the child can disappear as soon as the child is put on accept queue. Reported-by: Ilya Dryomov Fixes: ebb516af60e1 ("tcp/dccp: fix race at listener dismantle phase") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2016-02-16T17:56:00Z

Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contain a rather large batch for your net that includes accumulated bugfixes, they are: 1) Run conntrack cleanup from workqueue process context to avoid hitting soft lockup via watchdog for large tables. This is required by the IPv6 masquerading extension. From Florian Westphal. 2) Use original skbuff from nfnetlink batch when calling netlink_ack() on error since this needs to access the skb->sk pointer. 3) Incremental fix on top of recent Sasha Levin's lock fix for conntrack resizing. 4) Fix several problems in nfnetlink batch message header sanitization and error handling, from Phil Turnbull. 5) Select NF_DUP_IPV6 based on CONFIG_IPV6, from Arnd Bergmann. 6) Fix wrong signess in return values on nf_tables counter expression, from Anton Protopopov. Due to the NetDev 1.1 organization burden, I had no chance to pass up this to you any sooner in this release cycle, sorry about that. ==================== Signed-off-by: David S. Miller

tcp: do not drop syn_recv on all icmp reports

2016-02-09T09:15:37Z

Petr Novopashenniy reported that ICMP redirects on SYN_RECV sockets were leading to RST. This is of course incorrect. A specific list of ICMP messages should be able to drop a SYN_RECV. For instance, a REDIRECT on SYN_RECV shall be ignored, as we do not hold a dst per SYN_RECV pseudo request. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111751 Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table") Reported-by: Petr Novopashenniy Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6: fix a lockdep splat

2016-02-08T15:33:32Z

Silence lockdep false positive about rcu_dereference() being used in the wrong context. First one should use rcu_dereference_protected() as we own the spinlock. Second one should be a normal assignation, as no barrier is needed. Fixes: 18367681a10bd ("ipv6 flowlabel: Convert np->ipv6_fl_list to RCU.") Reported-by: Dave Jones Signed-off-by: Eric Dumazet Acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller