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2016-11-15packet: on direct_xmit, limit tso and csum to supported devicesWillem de Bruijn
[ Upstream commit 104ba78c98808ae837d1f63aae58c183db5505df ] When transmitting on a packet socket with PACKET_VNET_HDR and PACKET_QDISC_BYPASS, validate device support for features requested in vnet_hdr. Drop TSO packets sent to devices that do not support TSO or have the feature disabled. Note that the latter currently do process those packets correctly, regardless of not advertising the feature. Because of SKB_GSO_DODGY, it is not sufficient to test device features with netif_needs_gso. Full validate_xmit_skb is needed. Switch to software checksum for non-TSO packets that request checksum offload if that device feature is unsupported or disabled. Note that similar to the TSO case, device drivers may perform checksum offload correctly even when not advertising it. When switching to software checksum, packets hit skb_checksum_help, which has two BUG_ON checksum not in linear segment. Packet sockets always allocate at least up to csum_start + csum_off + 2 as linear. Tested by running github.com/wdebruij/kerneltools/psock_txring_vnet.c ethtool -K eth0 tso off tx on psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v -N ethtool -K eth0 tx off psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G -N v2: - add EXPORT_SYMBOL_GPL(validate_xmit_skb_list) Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option") Signed-off-by: Willem de Bruijn <willemb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-15net: add recursion limit to GROSabrina Dubroca
[ Upstream commit fcd91dd449867c6bfe56a81cabba76b829fd05cd ] Currently, GRO can do unlimited recursion through the gro_receive handlers. This was fixed for tunneling protocols by limiting tunnel GRO to one level with encap_mark, but both VLAN and TEB still have this problem. Thus, the kernel is vulnerable to a stack overflow, if we receive a packet composed entirely of VLAN headers. This patch adds a recursion counter to the GRO layer to prevent stack overflow. When a gro_receive function hits the recursion limit, GRO is aborted for this skb and it is processed normally. This recursion counter is put in the GRO CB, but could be turned into a percpu counter if we run out of space in the CB. Thanks to Vladimír Beneš <vbenes@redhat.com> for the initial bug report. Fixes: CVE-2016-7039 Fixes: 9b174d88c257 ("net: Add Transparent Ethernet Bridging GRO support.") Fixes: 66e5133f19e9 ("vlan: Add GRO support for non hardware accelerated vlan") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Jiri Benc <jbenc@redhat.com> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-15net: pktgen: remove rcu locking in pktgen_change_name()Eric Dumazet
[ Upstream commit 9a0b1e8ba4061778897b544afc898de2163382f7 ] After Jesper commit back in linux-3.18, we trigger a lockdep splat in proc_create_data() while allocating memory from pktgen_change_name(). This patch converts t->if_lock to a mutex, since it is now only used from control path, and adds proper locking to pktgen_change_name() 1) pktgen_thread_lock to protect the outer loop (iterating threads) 2) t->if_lock to protect the inner loop (iterating devices) Note that before Jesper patch, pktgen_change_name() was lacking proper protection, but lockdep was not able to detect the problem. Fixes: 8788370a1d4b ("pktgen: RCU-ify "if_list" to remove lock in next_to_run()") Reported-by: John Sperbeck <jsperbeck@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-15net: Add netdev all_adj_list refcnt propagation to fix panicAndrew Collins
[ Upstream commit 93409033ae653f1c9a949202fb537ab095b2092f ] This is a respin of a patch to fix a relatively easily reproducible kernel panic related to the all_adj_list handling for netdevs in recent kernels. The following sequence of commands will reproduce the issue: ip link add link eth0 name eth0.100 type vlan id 100 ip link add link eth0 name eth0.200 type vlan id 200 ip link add name testbr type bridge ip link set eth0.100 master testbr ip link set eth0.200 master testbr ip link add link testbr mac0 type macvlan ip link delete dev testbr This creates an upper/lower tree of (excuse the poor ASCII art): /---eth0.100-eth0 mac0-testbr- \---eth0.200-eth0 When testbr is deleted, the all_adj_lists are walked, and eth0 is deleted twice from the mac0 list. Unfortunately, during setup in __netdev_upper_dev_link, only one reference to eth0 is added, so this results in a panic. This change adds reference count propagation so things are handled properly. Matthias Schiffer reported a similar crash in batman-adv: https://github.com/freifunk-gluon/gluon/issues/680 https://www.open-mesh.org/issues/247 which this patch also seems to resolve. Signed-off-by: Andrew Collins <acollins@cradlepoint.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-11-15net: pktgen: fix pkt_sizePaolo Abeni
[ Upstream commit 63d75463c91a5b5be7c0aca11ceb45ea5a0ae81d ] The commit 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") increased the 'pkt_overhead' field value by LL_RESERVED_SPACE. As a side effect the generated packet size, computed as: /* Eth + IPh + UDPh + mpls */ datalen = pkt_dev->cur_pkt_size - 14 - 20 - 8 - pkt_dev->pkt_overhead; is decreased by the same value. The above changed slightly the behavior of existing pktgen users, and made the procfs interface somewhat inconsistent. Fix it by restoring the previous pkt_overhead value and using LL_RESERVED_SPACE as extralen in skb allocation. Also, change pktgen_alloc_skb() to only partially reserve the headroom to allow the caller to prefetch from ll header start. v1 -> v2: - fixed some typos in the comments Fixes: 879c7220e828 ("net: pktgen: Observe needed_headroom of the device") Suggested-by: Ben Greear <greearb@candelatech.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31tunnels: Don't apply GRO to multiple layers of encapsulation.Jesse Gross
commit fac8e0f579695a3ecbc4d3cac369139d7f819971 upstream. When drivers express support for TSO of encapsulated packets, they only mean that they can do it for one layer of encapsulation. Supporting additional levels would mean updating, at a minimum, more IP length fields and they are unaware of this. No encapsulation device expresses support for handling offloaded encapsulated packets, so we won't generate these types of frames in the transmit path. However, GRO doesn't have a check for multiple levels of encapsulation and will attempt to build them. UDP tunnel GRO actually does prevent this situation but it only handles multiple UDP tunnels stacked on top of each other. This generalizes that solution to prevent any kind of tunnel stacking that would cause problems. Fixes: bf5a755f ("net-gre-gro: Add GRE support to the GRO stack") Signed-off-by: Jesse Gross <jesse@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Juerg Haefliger <juerg.haefliger@hpe.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-30bonding: Fix bonding crashMahesh Bandewar
[ Upstream commit 24b27fc4cdf9e10c5e79e5923b6b7c2c5c95096c ] Following few steps will crash kernel - (a) Create bonding master > modprobe bonding miimon=50 (b) Create macvlan bridge on eth2 > ip link add link eth2 dev mvl0 address aa:0:0:0:0:01 \ type macvlan (c) Now try adding eth2 into the bond > echo +eth2 > /sys/class/net/bond0/bonding/slaves <crash> Bonding does lots of things before checking if the device enslaved is busy or not. In this case when the notifier call-chain sends notifications, the bond_netdev_event() assumes that the rx_handler /rx_handler_data is registered while the bond_enslave() hasn't progressed far enough to register rx_handler for the new slave. This patch adds a rx_handler check that can be performed right at the beginning of the enslave code to avoid getting into this situation. Signed-off-by: Mahesh Bandewar <maheshb@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-27net_sched: fix mirrored packets checksumWANG Cong
[ Upstream commit 82a31b9231f02d9c1b7b290a46999d517b0d312a ] Similar to commit 9b368814b336 ("net: fix bridge multicast packet checksum validation") we need to fixup the checksum for CHECKSUM_COMPLETE when pushing skb on RX path. Otherwise we get similar splats. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Tom Herbert <tom@herbertland.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-27packet: Use symmetric hash for PACKET_FANOUT_HASH.David S. Miller
[ Upstream commit eb70db8756717b90c01ccc765fdefc4dd969fc74 ] People who use PACKET_FANOUT_HASH want a symmetric hash, meaning that they want packets going in both directions on a flow to hash to the same bucket. The core kernel SKB hash became non-symmetric when the ipv6 flow label and other entities were incorporated into the standard flow hash order to increase entropy. But there are no users of PACKET_FANOUT_HASH who want an assymetric hash, they all want a symmetric one. Therefore, use the flow dissector to compute a flat symmetric hash over only the protocol, addresses and ports. This hash does not get installed into and override the normal skb hash, so this change has no effect whatsoever on the rest of the stack. Reported-by: Eric Leblond <eric@regit.org> Tested-by: Eric Leblond <eric@regit.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-11bpf: try harder on clones when writing into skbDaniel Borkmann
[ Upstream commit 3697649ff29e0f647565eed04b27a7779c646a22 ] When we're dealing with clones and the area is not writeable, try harder and get a copy via pskb_expand_head(). Replace also other occurences in tc actions with the new skb_try_make_writable(). Reported-by: Ashhad Sheikh <ashhadsheikh394@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-11neigh: Explicitly declare RCU-bh read side critical section in neigh_xmit()David Barroso
[ Upstream commit b560f03ddfb072bca65e9440ff0dc4f9b1d1f056 ] neigh_xmit() expects to be called inside an RCU-bh read side critical section, and while one of its two current callers gets this right, the other one doesn't. More specifically, neigh_xmit() has two callers, mpls_forward() and mpls_output(), and while both callers call neigh_xmit() under rcu_read_lock(), this provides sufficient protection for neigh_xmit() only in the case of mpls_forward(), as that is always called from softirq context and therefore doesn't need explicit BH protection, while mpls_output() can be called from process context with softirqs enabled. When mpls_output() is called from process context, with softirqs enabled, we can be preempted by a softirq at any time, and RCU-bh considers the completion of a softirq as signaling the end of any pending read-side critical sections, so if we do get a softirq while we are in the part of neigh_xmit() that expects to be run inside an RCU-bh read side critical section, we can end up with an unexpected RCU grace period running right in the middle of that critical section, making things go boom. This patch fixes this impedance mismatch in the callee, by making neigh_xmit() always take rcu_read_{,un}lock_bh() around the code that expects to be treated as an RCU-bh read side critical section, as this seems a safer option than fixing it in the callers. Fixes: 4fd3d7d9e868f ("neigh: Add helper function neigh_xmit") Signed-off-by: David Barroso <dbarroso@fastly.com> Signed-off-by: Lennert Buytenhek <lbuytenhek@fastly.com> Acked-by: David Ahern <dsa@cumulusnetworks.com> Acked-by: Robert Shearman <rshearma@brocade.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-18net: fix infoleak in rtnetlinkKangjie Lu
[ Upstream commit 5f8e44741f9f216e33736ea4ec65ca9ac03036e6 ] The stack object “map” has a total size of 32 bytes. Its last 4 bytes are padding generated by compiler. These padding bytes are not initialized and sent out via “nla_put”. Signed-off-by: Kangjie Lu <kjlu@gatech.edu> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-18vlan: pull on __vlan_insert_tag error path and fix csum correctionDaniel Borkmann
[ Upstream commit 9241e2df4fbc648a92ea0752918e05c26255649e ] When __vlan_insert_tag() fails from skb_vlan_push() path due to the skb_cow_head(), we need to undo the __skb_push() in the error path as well that was done earlier to move skb->data pointer to mac header. Moreover, I noticed that when in the non-error path the __skb_pull() is done and the original offset to mac header was non-zero, we fixup from a wrong skb->data offset in the checksum complete processing. So the skb_postpush_rcsum() really needs to be done before __skb_pull() where skb->data still points to the mac header start and thus operates under the same conditions as in __vlan_insert_tag(). Fixes: 93515d53b133 ("net: move vlan pop/push functions into common code") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-18net: use skb_postpush_rcsum instead of own implementationsDaniel Borkmann
[ Upstream commit 6b83d28a55a891a9d70fc61ccb1c138e47dcbe74 ] Replace individual implementations with the recently introduced skb_postpush_rcsum() helper. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Tom Herbert <tom@herbertland.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20tun, bpf: fix suspicious RCU usage in tun_{attach, detach}_filterDaniel Borkmann
[ Upstream commit 5a5abb1fa3b05dd6aa821525832644c1e7d2905f ] Sasha Levin reported a suspicious rcu_dereference_protected() warning found while fuzzing with trinity that is similar to this one: [ 52.765684] net/core/filter.c:2262 suspicious rcu_dereference_protected() usage! [ 52.765688] other info that might help us debug this: [ 52.765695] rcu_scheduler_active = 1, debug_locks = 1 [ 52.765701] 1 lock held by a.out/1525: [ 52.765704] #0: (rtnl_mutex){+.+.+.}, at: [<ffffffff816a64b7>] rtnl_lock+0x17/0x20 [ 52.765721] stack backtrace: [ 52.765728] CPU: 1 PID: 1525 Comm: a.out Not tainted 4.5.0+ #264 [...] [ 52.765768] Call Trace: [ 52.765775] [<ffffffff813e488d>] dump_stack+0x85/0xc8 [ 52.765784] [<ffffffff810f2fa5>] lockdep_rcu_suspicious+0xd5/0x110 [ 52.765792] [<ffffffff816afdc2>] sk_detach_filter+0x82/0x90 [ 52.765801] [<ffffffffa0883425>] tun_detach_filter+0x35/0x90 [tun] [ 52.765810] [<ffffffffa0884ed4>] __tun_chr_ioctl+0x354/0x1130 [tun] [ 52.765818] [<ffffffff8136fed0>] ? selinux_file_ioctl+0x130/0x210 [ 52.765827] [<ffffffffa0885ce3>] tun_chr_ioctl+0x13/0x20 [tun] [ 52.765834] [<ffffffff81260ea6>] do_vfs_ioctl+0x96/0x690 [ 52.765843] [<ffffffff81364af3>] ? security_file_ioctl+0x43/0x60 [ 52.765850] [<ffffffff81261519>] SyS_ioctl+0x79/0x90 [ 52.765858] [<ffffffff81003ba2>] do_syscall_64+0x62/0x140 [ 52.765866] [<ffffffff817d563f>] entry_SYSCALL64_slow_path+0x25/0x25 Same can be triggered with PROVE_RCU (+ PROVE_RCU_REPEATEDLY) enabled from tun_attach_filter() when user space calls ioctl(tun_fd, TUN{ATTACH, DETACH}FILTER, ...) for adding/removing a BPF filter on tap devices. Since the fix in f91ff5b9ff52 ("net: sk_{detach|attach}_filter() rcu fixes") sk_attach_filter()/sk_detach_filter() now dereferences the filter with rcu_dereference_protected(), checking whether socket lock is held in control path. Since its introduction in 994051625981 ("tun: socket filter support"), tap filters are managed under RTNL lock from __tun_chr_ioctl(). Thus the sock_owned_by_user(sk) doesn't apply in this specific case and therefore triggers the false positive. Extend the BPF API with __sk_attach_filter()/__sk_detach_filter() pair that is used by tap filters and pass in lockdep_rtnl_is_held() for the rcu_dereference_protected() checks instead. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20rtnl: fix msg size calculation in if_nlmsg_size()Nicolas Dichtel
[ Upstream commit c57c7a95da842807b475b823ed2e5435c42cb3b0 ] Size of the attribute IFLA_PHYS_PORT_NAME was missing. Fixes: db24a9044ee1 ("net: add support for phys_port_name") CC: David Ahern <dsahern@gmail.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-20net: fix bridge multicast packet checksum validationLinus Lüssing
[ Upstream commit 9b368814b336b0a1a479135eb2815edbc00efd3c ] We need to update the skb->csum after pulling the skb, otherwise an unnecessary checksum (re)computation can ocure for IGMP/MLD packets in the bridge code. Additionally this fixes the following splats for network devices / bridge ports with support for and enabled RX checksum offloading: [...] [ 43.986968] eth0: hw csum failure [ 43.990344] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.4.0 #2 [ 43.996193] Hardware name: BCM2709 [ 43.999647] [<800204e0>] (unwind_backtrace) from [<8001cf14>] (show_stack+0x10/0x14) [ 44.007432] [<8001cf14>] (show_stack) from [<801ab614>] (dump_stack+0x80/0x90) [ 44.014695] [<801ab614>] (dump_stack) from [<802e4548>] (__skb_checksum_complete+0x6c/0xac) [ 44.023090] [<802e4548>] (__skb_checksum_complete) from [<803a055c>] (ipv6_mc_validate_checksum+0x104/0x178) [ 44.032959] [<803a055c>] (ipv6_mc_validate_checksum) from [<802e111c>] (skb_checksum_trimmed+0x130/0x188) [ 44.042565] [<802e111c>] (skb_checksum_trimmed) from [<803a06e8>] (ipv6_mc_check_mld+0x118/0x338) [ 44.051501] [<803a06e8>] (ipv6_mc_check_mld) from [<803b2c98>] (br_multicast_rcv+0x5dc/0xd00) [ 44.060077] [<803b2c98>] (br_multicast_rcv) from [<803aa510>] (br_handle_frame_finish+0xac/0x51c) [...] Fixes: 9afd85c9e455 ("net: Export IGMP/MLD message validation code") Reported-by: Álvaro Fernández Rojas <noltari@gmail.com> Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03IFF_NO_QUEUE: Fix for drivers not calling ether_setup()Phil Sutter
[ Upstream commit a813104d923339144078939175faf4e66aca19b4 ] My implementation around IFF_NO_QUEUE driver flag assumed that leaving tx_queue_len untouched (specifically: not setting it to zero) by drivers would make it possible to assign a regular qdisc to them without having to worry about setting tx_queue_len to a useful value. This was only partially true: I overlooked that some drivers don't call ether_setup() and therefore not initialize tx_queue_len to the default value of 1000. Consequently, removing the workarounds in place for that case in qdisc implementations which cared about it (namely, pfifo, bfifo, gred, htb, plug and sfb) leads to problems with these specific interface types and qdiscs. Luckily, there's already a sanitization point for drivers setting tx_queue_len to zero, which can be reused to assign the fallback value most qdisc implementations used, which is 1. Fixes: 348e3435cbefa ("net: sched: drop all special handling of tx_queue_len == 0") Tested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Phil Sutter <phil@nwl.cc> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03flow_dissector: Fix unaligned access in __skb_flow_dissector when used by ↵Alexander Duyck
eth_get_headlen [ Upstream commit 461547f3158978c180d74484d58e82be9b8e7357 ] This patch fixes an issue with unaligned accesses when using eth_get_headlen on a page that was DMA aligned instead of being IP aligned. The fact is when trying to check the length we don't need to be looking at the flow label so we can reorder the checks to first check if we are supposed to gather the flow label and then make the call to actually get it. v2: Updated path so that either STOP_AT_FLOW_LABEL or KEY_FLOW_LABEL can cause us to check for the flow label. Reported-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03net: Copy inner L3 and L4 headers as unaligned on GRE TEBAlexander Duyck
[ Upstream commit 78565208d73ca9b654fb9a6b142214d52eeedfd1 ] This patch corrects the unaligned accesses seen on GRE TEB tunnels when generating hash keys. Specifically what this patch does is make it so that we force the use of skb_copy_bits when the GRE inner headers will be unaligned due to NET_IP_ALIGNED being a non-zero value. Signed-off-by: Alexander Duyck <aduyck@mirantis.com> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03net:Add sysctl_max_skb_fragsHans Westgaard Ry
[ Upstream commit 5f74f82ea34c0da80ea0b49192bb5ea06e063593 ] Devices may have limits on the number of fragments in an skb they support. Current codebase uses a constant as maximum for number of fragments one skb can hold and use. When enabling scatter/gather and running traffic with many small messages the codebase uses the maximum number of fragments and may thereby violate the max for certain devices. The patch introduces a global variable as max number of fragments. Signed-off-by: Hans Westgaard Ry <hans.westgaard.ry@oracle.com> Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03unix: correctly track in-flight fds in sending process user_structHannes Frederic Sowa
[ Upstream commit 415e3d3e90ce9e18727e8843ae343eda5a58fad6 ] The commit referenced in the Fixes tag incorrectly accounted the number of in-flight fds over a unix domain socket to the original opener of the file-descriptor. This allows another process to arbitrary deplete the original file-openers resource limit for the maximum of open files. Instead the sending processes and its struct cred should be credited. To do so, we add a reference counted struct user_struct pointer to the scm_fp_list and use it to account for the number of inflight unix fds. Fixes: 712f4aad406bb1 ("unix: properly account for FDs passed over unix sockets") Reported-by: David Herrmann <dh.herrmann@gmail.com> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Linus Torvalds <torvalds@linux-foundation.org> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-03gro: Make GRO aware of lightweight tunnels.Jesse Gross
[ Upstream commit ce87fc6ce3f9f4488546187e3757cf666d9d4a2a ] GRO is currently not aware of tunnel metadata generated by lightweight tunnels and stored in the dst. This leads to two possible problems: * Incorrectly merging two frames that have different metadata. * Leaking of allocated metadata from merged frames. This avoids those problems by comparing the tunnel information before merging, similar to how we handle other metadata (such as vlan tags), and releasing any state when we are done. Reported-by: John <john.phillips5@hpe.com> Fixes: 2e15ea39 ("ip_gre: Add support to collect tunnel metadata.") Signed-off-by: Jesse Gross <jesse@kernel.org> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31net: bpf: reject invalid shiftsRabin Vincent
[ Upstream commit 229394e8e62a4191d592842cf67e80c62a492937 ] On ARM64, a BUG() is triggered in the eBPF JIT if a filter with a constant shift that can't be encoded in the immediate field of the UBFM/SBFM instructions is passed to the JIT. Since these shifts amounts, which are negative or >= regsize, are invalid, reject them in the eBPF verifier and the classic BPF filter checker, for all architectures. Signed-off-by: Rabin Vincent <rabin@rab.in> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31net: preserve IP control block during GSO segmentationKonstantin Khlebnikov
[ Upstream commit 9207f9d45b0ad071baa128e846d7e7ed85016df3 ] Skb_gso_segment() uses skb control block during segmentation. This patch adds 32-bytes room for previous control block which will be copied into all resulting segments. This patch fixes kernel crash during fragmenting forwarded packets. Fragmentation requires valid IP CB in skb for clearing ip options. Also patch removes custom save/restore in ovs code, now it's redundant. Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Link: http://lkml.kernel.org/r/CALYGNiP-0MZ-FExV2HutTvE9U-QQtkKSoE--KN=JQE5STYsjAA@mail.gmail.com Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-31net: pktgen: fix null ptr deref in skb allocationJohn Fastabend
[ Upstream commit 3de03596dfeee48bc803c1d1a6daf60a459929f3 ] Fix possible null pointer dereference that may occur when calling skb_reserve() on a null skb. Fixes: 879c7220e82 ("net: pktgen: Observe needed_headroom of the device") Signed-off-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-06net: possible use after free in dst_releaseFrancesco Ruggeri
dst_release should not access dst->flags after decrementing __refcnt to 0. The dst_entry may be in dst_busy_list and dst_gc_task may dst_destroy it before dst_release gets a chance to access dst->flags. Fixes: d69bbf88c8d0 ("net: fix a race in dst_release()") Fixes: 27b75c95f10d ("net: avoid RCU for NOCACHE dst") Signed-off-by: Francesco Ruggeri <fruggeri@arista.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix uninitialized variable warnings in nfnetlink_queue, a lot of people reported this... From Arnd Bergmann. 2) Don't init mutex twice in i40e driver, from Jesse Brandeburg. 3) Fix spurious EBUSY in rhashtable, from Herbert Xu. 4) Missing DMA unmaps in mvpp2 driver, from Marcin Wojtas. 5) Fix race with work structure access in pppoe driver causing corruptions, from Guillaume Nault. 6) Fix OOPS due to sh_eth_rx() not checking whether netdev_alloc_skb() actually succeeded or not, from Sergei Shtylyov. 7) Don't lose flags when settifn IFA_F_OPTIMISTIC in ipv6 code, from Bjørn Mork. 8) VXLAN_HD_RCO defined incorrectly, fix from Jiri Benc. 9) Fix clock source used for cookies in SCTP, from Marcelo Ricardo Leitner. 10) aurora driver needs HAS_DMA dependency, from Geert Uytterhoeven. 11) ndo_fill_metadata_dst op of vxlan has to handle ipv6 tunneling properly as well, from Jiri Benc. 12) Handle request sockets properly in xfrm layer, from Eric Dumazet. 13) Double stats update in ipv6 geneve transmit path, fix from Pravin B Shelar. 14) sk->sk_policy[] needs RCU protection, and as a result xfrm_policy_destroy() needs to free policies using an RCU grace period, from Eric Dumazet. 15) SCTP needs to clone ipv6 tx options in order to avoid use after free, from Eric Dumazet. 16) Missing kbuild export if ila.h, from Stephen Hemminger. 17) Missing mdiobus_alloc() return value checking in mdio-mux.c, from Tobias Klauser. 18) Validate protocol value range in ->create() methods, from Hannes Frederic Sowa. 19) Fix early socket demux races that result in illegal dst reuse, from Eric Dumazet. 20) Validate socket address length in pptp code, from WANG Cong. 21) skb_reorder_vlan_header() uses incorrect offset and can corrupt packets, from Vlad Yasevich. 22) Fix memory leaks in nl80211 registry code, from Ola Olsson. 23) Timeout loop count handing fixes in mISDN, xgbe, qlge, sfc, and qlcnic. From Dan Carpenter. 24) msg.msg_iocb needs to be cleared in recvfrom() otherwise, for example, AF_ALG will interpret it as an async call. From Tadeusz Struk. 25) inetpeer_set_addr_v4 forgets to initialize the 'vif' field, from Eric Dumazet. 26) rhashtable enforces the minimum table size not early enough, breaking how we calculate the per-cpu lock allocations. From Herbert Xu. 27) Fix FCC port lockup in 82xx driver, from Martin Roth. 28) FOU sockets need to be freed using RCU, from Hannes Frederic Sowa. 29) Fix out-of-bounds access in __skb_complete_tx_timestamp() and sock_setsockopt() wrt. timestamp handling. From WANG Cong. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (117 commits) net: check both type and procotol for tcp sockets drivers: net: xgene: fix Tx flow control tcp: restore fastopen with no data in SYN packet af_unix: Revert 'lock_interruptible' in stream receive code fou: clean up socket with kfree_rcu 82xx: FCC: Fixing a bug causing to FCC port lock-up gianfar: Don't enable RX Filer if not supported net: fix warnings in 'make htmldocs' by moving macro definition out of field declaration rhashtable: Fix walker list corruption rhashtable: Enforce minimum size on initial hash table inet: tcp: fix inetpeer_set_addr_v4() ipv6: automatically enable stable privacy mode if stable_secret set net: fix uninitialized variable issue bluetooth: Validate socket address length in sco_sock_bind(). net_sched: make qdisc_tree_decrease_qlen() work for non mq ser_gigaset: remove unnecessary kfree() calls from release method ser_gigaset: fix deallocation of platform device structure ser_gigaset: turn nonsense checks into WARN_ON ser_gigaset: fix up NULL checks qlcnic: fix a timeout loop ...
2015-12-17net: check both type and procotol for tcp socketsWANG Cong
Dmitry reported the following out-of-bound access: Call Trace: [<ffffffff816cec2e>] __asan_report_load4_noabort+0x3e/0x40 mm/kasan/report.c:294 [<ffffffff84affb14>] sock_setsockopt+0x1284/0x13d0 net/core/sock.c:880 [< inline >] SYSC_setsockopt net/socket.c:1746 [<ffffffff84aed7ee>] SyS_setsockopt+0x1fe/0x240 net/socket.c:1729 [<ffffffff85c18c76>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185 This is because we mistake a raw socket as a tcp socket. We should check both sk->sk_type and sk->sk_protocol to ensure it is a tcp socket. Willem points out __skb_complete_tx_timestamp() needs to fix as well. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-15skbuff: Fix offset error in skb_reorder_vlan_headerVlad Yasevich
skb_reorder_vlan_header is called after the vlan header has been pulled. As a result the offset of the begining of the mac header has been incrased by 4 bytes (VLAN_HLEN). When moving the mac addresses, include this incrase in the offset calcualation so that the mac addresses are copied correctly. Fixes: a6e18ff1117 (vlan: Fix untag operations of stacked vlans with REORDER_HEADER off) CC: Nicolas Dichtel <nicolas.dichtel@6wind.com> CC: Patrick McHardy <kaber@trash.net> Signed-off-by: Vladislav Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-11xfrm: add rcu protection to sk->sk_policy[]Eric Dumazet
XFRM can deal with SYNACK messages, sent while listener socket is not locked. We add proper rcu protection to __xfrm_sk_clone_policy() and xfrm_sk_policy_lookup() This might serve as the first step to remove xfrm.xfrm_policy_lock use in fast path. Fixes: fa76ce7328b2 ("inet: get rid of central tcp/dccp listener timer") Signed-off-by: Eric Dumazet <edumazet@google.com> Acked-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-07Merge branch 'master' into for-4.4-fixesTejun Heo
The following commit which went into mainline through networking tree 3b13758f51de ("cgroups: Allow dynamically changing net_classid") conflicts in net/core/netclassid_cgroup.c with the following pending fix in cgroup/for-4.4-fixes. 1f7dd3e5a6e4 ("cgroup: fix handling of multi-destination migration from subtree_control enabling") The former separates out update_classid() from cgrp_attach() and updates it to walk all fds of all tasks in the target css so that it can be used from both migration and config change paths. The latter drops @css from cgrp_attach(). Resolve the conflict by making cgrp_attach() call update_classid() with the css from the first task. We can revive @tset walking in cgrp_attach() but given that net_cls is v1 only where there always is only one target css during migration, this is fine. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Nina Schiff <ninasc@fb.com>
2015-12-05sctp: update the netstamp_needed counter when copying socketsMarcelo Ricardo Leitner
Dmitry Vyukov reported that SCTP was triggering a WARN on socket destroy related to disabling sock timestamp. When SCTP accepts an association or peel one off, it copies sock flags but forgot to call net_enable_timestamp() if a packet timestamping flag was copied, leading to extra calls to net_disable_timestamp() whenever such clones were closed. The fix is to call net_enable_timestamp() whenever we copy a sock with that flag on, like tcp does. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03ipv6: kill sk_dst_lockEric Dumazet
While testing the np->opt RCU conversion, I found that UDP/IPv6 was using a mixture of xchg() and sk_dst_lock to protect concurrent changes to sk->sk_dst_cache, leading to possible corruptions and crashes. ip6_sk_dst_lookup_flow() uses sk_dst_check() anyway, so the simplest way to fix the mess is to remove sk_dst_lock completely, as we did for IPv4. __ip6_dst_store() and ip6_dst_store() share same implementation. sk_setup_caps() being called with socket lock being held or not, we have to use sk_dst_set() instead of __sk_dst_set() Note that I had to move the "np->dst_cookie = rt6_get_cookie(rt);" in ip6_dst_store() before the sk_setup_caps(sk, dst) call. This is because ip6_dst_store() can be called from process context, without any lock held. As soon as the dst is installed in sk->sk_dst_cache, dst can be freed from another cpu doing a concurrent ip6_dst_store() Doing the dst dereference before doing the install is needed to make sure no use after free would trigger. Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03cgroup: fix handling of multi-destination migration from subtree_control ↵Tejun Heo
enabling Consider the following v2 hierarchy. P0 (+memory) --- P1 (-memory) --- A \- B P0 has memory enabled in its subtree_control while P1 doesn't. If both A and B contain processes, they would belong to the memory css of P1. Now if memory is enabled on P1's subtree_control, memory csses should be created on both A and B and A's processes should be moved to the former and B's processes the latter. IOW, enabling controllers can cause atomic migrations into different csses. The core cgroup migration logic has been updated accordingly but the controller migration methods haven't and still assume that all tasks migrate to a single target css; furthermore, the methods were fed the css in which subtree_control was updated which is the parent of the target csses. pids controller depends on the migration methods to move charges and this made the controller attribute charges to the wrong csses often triggering the following warning by driving a counter negative. WARNING: CPU: 1 PID: 1 at kernel/cgroup_pids.c:97 pids_cancel.constprop.6+0x31/0x40() Modules linked in: CPU: 1 PID: 1 Comm: systemd Not tainted 4.4.0-rc1+ #29 ... ffffffff81f65382 ffff88007c043b90 ffffffff81551ffc 0000000000000000 ffff88007c043bc8 ffffffff810de202 ffff88007a752000 ffff88007a29ab00 ffff88007c043c80 ffff88007a1d8400 0000000000000001 ffff88007c043bd8 Call Trace: [<ffffffff81551ffc>] dump_stack+0x4e/0x82 [<ffffffff810de202>] warn_slowpath_common+0x82/0xc0 [<ffffffff810de2fa>] warn_slowpath_null+0x1a/0x20 [<ffffffff8118e031>] pids_cancel.constprop.6+0x31/0x40 [<ffffffff8118e0fd>] pids_can_attach+0x6d/0xf0 [<ffffffff81188a4c>] cgroup_taskset_migrate+0x6c/0x330 [<ffffffff81188e05>] cgroup_migrate+0xf5/0x190 [<ffffffff81189016>] cgroup_attach_task+0x176/0x200 [<ffffffff8118949d>] __cgroup_procs_write+0x2ad/0x460 [<ffffffff81189684>] cgroup_procs_write+0x14/0x20 [<ffffffff811854e5>] cgroup_file_write+0x35/0x1c0 [<ffffffff812e26f1>] kernfs_fop_write+0x141/0x190 [<ffffffff81265f88>] __vfs_write+0x28/0xe0 [<ffffffff812666fc>] vfs_write+0xac/0x1a0 [<ffffffff81267019>] SyS_write+0x49/0xb0 [<ffffffff81bcef32>] entry_SYSCALL_64_fastpath+0x12/0x76 This patch fixes the bug by removing @css parameter from the three migration methods, ->can_attach, ->cancel_attach() and ->attach() and updating cgroup_taskset iteration helpers also return the destination css in addition to the task being migrated. All controllers are updated accordingly. * Controllers which don't care whether there are one or multiple target csses can be converted trivially. cpu, io, freezer, perf, netclassid and netprio fall in this category. * cpuset's current implementation assumes that there's single source and destination and thus doesn't support v2 hierarchy already. The only change made by this patchset is how that single destination css is obtained. * memory migration path already doesn't do anything on v2. How the single destination css is obtained is updated and the prep stage of mem_cgroup_can_attach() is reordered to accomodate the change. * pids is the only controller which was affected by this bug. It now correctly handles multi-destination migrations and no longer causes counter underflow from incorrect accounting. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Cc: Aleksa Sarai <cyphar@cyphar.com>
2015-12-03net/neighbour: fix crash at dumping device-agnostic proxy entriesKonstantin Khlebnikov
Proxy entries could have null pointer to net-device. Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Fixes: 84920c1420e2 ("net: Allow ipv6 proxies and arp proxies be shown with iproute2") Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01net: fix sock_wake_async() rcu protectionEric Dumazet
Dmitry provided a syzkaller (http://github.com/google/syzkaller) triggering a fault in sock_wake_async() when async IO is requested. Said program stressed af_unix sockets, but the issue is generic and should be addressed in core networking stack. The problem is that by the time sock_wake_async() is called, we should not access the @flags field of 'struct socket', as the inode containing this socket might be freed without further notice, and without RCU grace period. We already maintain an RCU protected structure, "struct socket_wq" so moving SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA into it is the safe route. It also reduces number of cache lines needing dirtying, so might provide a performance improvement anyway. In followup patches, we might move remaining flags (SOCK_NOSPACE, SOCK_PASSCRED, SOCK_PASSSEC) to save 8 bytes and let 'struct socket' being mostly read and let it being shared between cpus. Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATAEric Dumazet
This patch is a cleanup to make following patch easier to review. Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA from (struct socket)->flags to a (struct socket_wq)->flags to benefit from RCU protection in sock_wake_async() To ease backports, we rename both constants. Two new helpers, sk_set_bit(int nr, struct sock *sk) and sk_clear_bit(int net, struct sock *sk) are added so that following patch can change their implementation. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-23cgroups: Allow dynamically changing net_classidNina Schiff
The classid of a process is changed either when a process is moved to or from a cgroup or when the net_cls.classid file is updated. Previously net_cls only supported propogating these changes to the cgroup's related sockets when a process was added or removed from the cgroup. This means it was neccessary to remove and re-add all processes to a cgroup in order to update its classid. This change introduces support for doing this dynamically - i.e. when the value is changed in the net_cls_classid file, this will also trigger an update to the classid associated with all sockets controlled by the cgroup. This mimics the behaviour of other cgroup subsystems. net_prio circumvents this issue by storing an index into a table with each socket (and so any updates to the table, don't require updating the value associated with the socket). net_cls, however, passes the socket the classid directly, and so this additional step is needed. Signed-off-by: Nina Schiff <ninasc@fb.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-22net, scm: fix PaX detected msg_controllen overflow in scm_detach_fdsDaniel Borkmann
David and HacKurx reported a following/similar size overflow triggered in a grsecurity kernel, thanks to PaX's gcc size overflow plugin: (Already fixed in later grsecurity versions by Brad and PaX Team.) [ 1002.296137] PAX: size overflow detected in function scm_detach_fds net/core/scm.c:314 cicus.202_127 min, count: 4, decl: msg_controllen; num: 0; context: msghdr; [ 1002.296145] CPU: 0 PID: 3685 Comm: scm_rights_recv Not tainted 4.2.3-grsec+ #7 [ 1002.296149] Hardware name: Apple Inc. MacBookAir5,1/Mac-66F35F19FE2A0D05, [...] [ 1002.296153] ffffffff81c27366 0000000000000000 ffffffff81c27375 ffffc90007843aa8 [ 1002.296162] ffffffff818129ba 0000000000000000 ffffffff81c27366 ffffc90007843ad8 [ 1002.296169] ffffffff8121f838 fffffffffffffffc fffffffffffffffc ffffc90007843e60 [ 1002.296176] Call Trace: [ 1002.296190] [<ffffffff818129ba>] dump_stack+0x45/0x57 [ 1002.296200] [<ffffffff8121f838>] report_size_overflow+0x38/0x60 [ 1002.296209] [<ffffffff816a979e>] scm_detach_fds+0x2ce/0x300 [ 1002.296220] [<ffffffff81791899>] unix_stream_read_generic+0x609/0x930 [ 1002.296228] [<ffffffff81791c9f>] unix_stream_recvmsg+0x4f/0x60 [ 1002.296236] [<ffffffff8178dc00>] ? unix_set_peek_off+0x50/0x50 [ 1002.296243] [<ffffffff8168fac7>] sock_recvmsg+0x47/0x60 [ 1002.296248] [<ffffffff81691522>] ___sys_recvmsg+0xe2/0x1e0 [ 1002.296257] [<ffffffff81693496>] __sys_recvmsg+0x46/0x80 [ 1002.296263] [<ffffffff816934fc>] SyS_recvmsg+0x2c/0x40 [ 1002.296271] [<ffffffff8181a3ab>] entry_SYSCALL_64_fastpath+0x12/0x85 Further investigation showed that this can happen when an *odd* number of fds are being passed over AF_UNIX sockets. In these cases CMSG_LEN(i * sizeof(int)) and CMSG_SPACE(i * sizeof(int)), where i is the number of successfully passed fds, differ by 4 bytes due to the extra CMSG_ALIGN() padding in CMSG_SPACE() to an 8 byte boundary on 64 bit. The padding is used to align subsequent cmsg headers in the control buffer. When the control buffer passed in from the receiver side *lacks* these 4 bytes (e.g. due to buggy/wrong API usage), then msg->msg_controllen will overflow in scm_detach_fds(): int cmlen = CMSG_LEN(i * sizeof(int)); <--- cmlen w/o tail-padding err = put_user(SOL_SOCKET, &cm->cmsg_level); if (!err) err = put_user(SCM_RIGHTS, &cm->cmsg_type); if (!err) err = put_user(cmlen, &cm->cmsg_len); if (!err) { cmlen = CMSG_SPACE(i * sizeof(int)); <--- cmlen w/ 4 byte extra tail-padding msg->msg_control += cmlen; msg->msg_controllen -= cmlen; <--- iff no tail-padding space here ... } ... wrap-around F.e. it will wrap to a length of 18446744073709551612 bytes in case the receiver passed in msg->msg_controllen of 20 bytes, and the sender properly transferred 1 fd to the receiver, so that its CMSG_LEN results in 20 bytes and CMSG_SPACE in 24 bytes. In case of MSG_CMSG_COMPAT (scm_detach_fds_compat()), I haven't seen an issue in my tests as alignment seems always on 4 byte boundary. Same should be in case of native 32 bit, where we end up with 4 byte boundaries as well. In practice, passing msg->msg_controllen of 20 to recvmsg() while receiving a single fd would mean that on successful return, msg->msg_controllen is being set by the kernel to 24 bytes instead, thus more than the input buffer advertised. It could f.e. become an issue if such application later on zeroes or copies the control buffer based on the returned msg->msg_controllen elsewhere. Maximum number of fds we can send is a hard upper limit SCM_MAX_FD (253). Going over the code, it seems like msg->msg_controllen is not being read after scm_detach_fds() in scm_recv() anymore by the kernel, good! Relevant recvmsg() handler are unix_dgram_recvmsg() (unix_seqpacket_recvmsg()) and unix_stream_recvmsg(). Both return back to their recvmsg() caller, and ___sys_recvmsg() places the updated length, that is, new msg_control - old msg_control pointer into msg->msg_controllen (hence the 24 bytes seen in the example). Long time ago, Wei Yongjun fixed something related in commit 1ac70e7ad24a ("[NET]: Fix function put_cmsg() which may cause usr application memory overflow"). RFC3542, section 20.2. says: The fields shown as "XX" are possible padding, between the cmsghdr structure and the data, and between the data and the next cmsghdr structure, if required by the implementation. While sending an application may or may not include padding at the end of last ancillary data in msg_controllen and implementations must accept both as valid. On receiving a portable application must provide space for padding at the end of the last ancillary data as implementations may copy out the padding at the end of the control message buffer and include it in the received msg_controllen. When recvmsg() is called if msg_controllen is too small for all the ancillary data items including any trailing padding after the last item an implementation may set MSG_CTRUNC. Since we didn't place MSG_CTRUNC for already quite a long time, just do the same as in 1ac70e7ad24a to avoid an overflow. Btw, even man-page author got this wrong :/ See db939c9b26e9 ("cmsg.3: Fix error in SCM_RIGHTS code sample"). Some people must have copied this (?), thus it got triggered in the wild (reported several times during boot by David and HacKurx). No Fixes tag this time as pre 2002 (that is, pre history tree). Reported-by: David Sterba <dave@jikos.cz> Reported-by: HacKurx <hackurx@gmail.com> Cc: PaX Team <pageexec@freemail.hu> Cc: Emese Revfy <re.emese@gmail.com> Cc: Brad Spengler <spender@grsecurity.net> Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Eric Dumazet <edumazet@google.com> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-17net/core: revert "net: fix __netdev_update_features return.." and add commentNikolay Aleksandrov
This reverts commit 00ee59271777 ("net: fix __netdev_update_features return on ndo_set_features failure") and adds a comment explaining why it's okay to return a value other than 0 upon error. Some drivers might actually change flags and return an error so it's better to fire a spurious notification rather than miss these. CC: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-17rtnetlink: fix frame size warning in rtnl_fill_ifinfoHannes Frederic Sowa
Fix the following warning: CC net/core/rtnetlink.o net/core/rtnetlink.c: In function ‘rtnl_fill_ifinfo’: net/core/rtnetlink.c:1308:1: warning: the frame size of 2864 bytes is larger than 2048 bytes [-Wframe-larger-than=] } ^ by splitting up the huge rtnl_fill_ifinfo into some smaller ones, so we don't have the huge frame allocations at the same time. Cc: Eric Dumazet <edumazet@google.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-17net: use skb_clone to avoid alloc_pages failure.Martin Zhang
1. new skb only need dst and ip address(v4 or v6). 2. skb_copy may need high order pages, which is very rare on long running server. Signed-off-by: Junwei Zhang <linggao.zjw@alibaba-inc.com> Signed-off-by: Martin Zhang <martinbj2008@gmail.com> Acked-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-17vlan: Fix untag operations of stacked vlans with REORDER_HEADER offVlad Yasevich
When we have multiple stacked vlan devices all of which have turned off REORDER_HEADER flag, the untag operation does not locate the ethernet addresses correctly for nested vlans. The reason is that in case of REORDER_HEADER flag being off, the outer vlan headers are put back and the mac_len is adjusted to account for the presense of the header. Then, the subsequent untag operation, for the next level vlan, always use VLAN_ETH_HLEN to locate the begining of the ethernet header and that ends up being a multiple of 4 bytes short of the actuall beginning of the mac header (the multiple depending on the how many vlan encapsulations ethere are). As a reslult, if there are multiple levles of vlan devices with REODER_HEADER being off, the recevied packets end up being dropped. To solve this, we use skb->mac_len as the offset. The value is always set on receive path and starts out as a ETH_HLEN. The value is also updated when the vlan header manupations occur so we know it will be correct. Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-16net/core: use netdev name in warning if no parentBjørn Mork
A recent flaw in the netdev feature setting resulted in warnings like this one from VLAN interfaces: WARNING: CPU: 1 PID: 4975 at net/core/dev.c:2419 skb_warn_bad_offload+0xbc/0xcb() : caps=(0x00000000001b5820, 0x00000000001b5829) len=2782 data_len=0 gso_size=1348 gso_type=16 ip_summed=3 The ":" is supposed to be preceded by a driver name, but in this case it is an empty string since the device has no parent. There are many types of network devices without a parent. The anonymous warnings for these devices can be hard to debug. Log the network device name instead in these cases to assist further debugging. This is mostly similar to how __netdev_printk() handles orphan devices. Signed-off-by: Bjørn Mork <bjorn@mork.no> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-16net: fix __netdev_update_features return on ndo_set_features failureNikolay Aleksandrov
If ndo_set_features fails __netdev_update_features() will return -1 but this is wrong because it is expected to return 0 if no features were changed (see netdev_update_features()), which will cause a netdev notifier to be called without any actual changes. Fix this by returning 0 if ndo_set_features fails. Fixes: 6cb6a27c45ce ("net: Call netdev_features_change() from netdev_update_features()") CC: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-16net: fix feature changes on devices without ndo_set_featuresNikolay Aleksandrov
When __netdev_update_features() was updated to ensure some features are disabled on new lower devices, an error was introduced for devices which don't have the ndo_set_features() method set. Before we'll just set the new features, but now we return an error and don't set them. Fix this by returning the old behaviour and setting err to 0 when ndo_set_features is not present. Fixes: e7868a85e1b2 ("net/core: ensure features get disabled on new lower devs") CC: Jarod Wilson <jarod@redhat.com> CC: Jiri Pirko <jiri@resnulli.us> CC: Ido Schimmel <idosch@mellanox.com> CC: Sander Eikelenboom <linux@eikelenboom.it> CC: Andy Gospodarek <gospo@cumulusnetworks.com> CC: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Reviewed-by: Andy Gospodarek <gospo@cumulusnetworks.com> Reviewed-by: Jarod Wilson <jarod@redhat.com> Tested-by: Florian Fainelli <f.fainelli@gmail.com> Tested-by: Dave Young <dyoung@redhat.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix null deref in xt_TEE netfilter module, from Eric Dumazet. 2) Several spots need to get to the original listner for SYN-ACK packets, most spots got this ok but some were not. Whilst covering the remaining cases, create a helper to do this. From Eric Dumazet. 3) Missiing check of return value from alloc_netdev() in CAIF SPI code, from Rasmus Villemoes. 4) Don't sleep while != TASK_RUNNING in macvtap, from Vlad Yasevich. 5) Use after free in mvneta driver, from Justin Maggard. 6) Fix race on dst->flags access in dst_release(), from Eric Dumazet. 7) Add missing ZLIB_INFLATE dependency for new qed driver. From Arnd Bergmann. 8) Fix multicast getsockopt deadlock, from WANG Cong. 9) Fix deadlock in btusb, from Kuba Pawlak. 10) Some ipv6_add_dev() failure paths were not cleaning up the SNMP6 counter state. From Sabrina Dubroca. 11) Fix packet_bind() race, which can cause lost notifications, from Francesco Ruggeri. 12) Fix MAC restoration in qlcnic driver during bonding mode changes, from Jarod Wilson. 13) Revert bridging forward delay change which broke libvirt and other userspace things, from Vlad Yasevich. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits) Revert "bridge: Allow forward delay to be cfgd when STP enabled" bpf_trace: Make dependent on PERF_EVENTS qed: select ZLIB_INFLATE net: fix a race in dst_release() net: mvneta: Fix memory use after free. net: Documentation: Fix default value tcp_limit_output_bytes macvtap: Resolve possible __might_sleep warning in macvtap_do_read() mvneta: add FIXED_PHY dependency net: caif: check return value of alloc_netdev net: hisilicon: NET_VENDOR_HISILICON should depend on HAS_DMA drivers: net: xgene: fix RGMII 10/100Mb mode netfilter: nft_meta: use skb_to_full_sk() helper net_sched: em_meta: use skb_to_full_sk() helper sched: cls_flow: use skb_to_full_sk() helper netfilter: xt_owner: use skb_to_full_sk() helper smack: use skb_to_full_sk() helper net: add skb_to_full_sk() helper and use it in selinux_netlbl_skbuff_setsid() bpf: doc: correct arch list for supported eBPF JIT dwc_eth_qos: Delete an unnecessary check before the function call "of_node_put" bonding: fix panic on non-ARPHRD_ETHER enslave failure ...
2015-11-09net: fix a race in dst_release()Eric Dumazet
Only cpu seeing dst refcount going to 0 can safely dereference dst->flags. Otherwise an other cpu might already have freed the dst. Fixes: 27b75c95f10d ("net: avoid RCU for NOCACHE dst") Reported-by: Greg Thelen <gthelen@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-06mm, page_alloc: distinguish between being unable to sleep, unwilling to ↵Mel Gorman
sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>