kernel/linux.git/net, branch v3.14.76

tcp: make challenge acks less predictable

2016-08-16T07:29:03+00:00

[ Upstream commit 75ff39ccc1bd5d3c455b6822ab09e533c551f758 ] Yue Cao claims that current host rate limiting of challenge ACKS (RFC 5961) could leak enough information to allow a patient attacker to hijack TCP sessions. He will soon provide details in an academic paper. This patch increases the default limit from 100 to 1000, and adds some randomization so that the attacker can no longer hijack sessions without spending a considerable amount of probes. Based on initial analysis and patch from Linus. Note that we also have per socket rate limiting, so it is tempting to remove the host limit in the future. v2: randomize the count of challenge acks per second, not the period. Fixes: 282f23c6ee34 ("tcp: implement RFC 5961 3.2") Reported-by: Yue Cao Signed-off-by: Eric Dumazet Suggested-by: Linus Torvalds Cc: Yuchung Cheng Cc: Neal Cardwell Acked-by: Neal Cardwell Acked-by: Yuchung Cheng Signed-off-by: David S. Miller

tcp: consider recv buf for the initial window scale

2016-08-16T07:29:03+00:00

[ Upstream commit f626300a3e776ccc9671b0dd94698fb3aa315966 ] tcp_select_initial_window() intends to advertise a window scaling for the maximum possible window size. To do so, it considers the maximum of net.ipv4.tcp_rmem[2] and net.core.rmem_max as the only possible upper-bounds. However, users with CAP_NET_ADMIN can use SO_RCVBUFFORCE to set the socket's receive buffer size to values larger than net.ipv4.tcp_rmem[2] and net.core.rmem_max. Thus, SO_RCVBUFFORCE is effectively ignored by tcp_select_initial_window(). To fix this, consider the maximum of net.ipv4.tcp_rmem[2], net.core.rmem_max and socket's initial buffer space. Fixes: b0573dea1fb3 ("[NET]: Introduce SO_{SND,RCV}BUFFORCE socket options") Signed-off-by: Soheil Hassas Yeganeh Suggested-by: Neal Cardwell Acked-by: Neal Cardwell Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net/irda: fix NULL pointer dereference on memory allocation failure

2016-08-16T07:29:03+00:00

[ Upstream commit d3e6952cfb7ba5f4bfa29d4803ba91f96ce1204d ] I ran into this: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 2 PID: 2012 Comm: trinity-c3 Not tainted 4.7.0-rc7+ #19 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff8800b745f2c0 ti: ffff880111740000 task.ti: ffff880111740000 RIP: 0010:[] [] irttp_connect_request+0x36/0x710 RSP: 0018:ffff880111747bb8 EFLAGS: 00010286 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000069dd8358 RDX: 0000000000000009 RSI: 0000000000000027 RDI: 0000000000000048 RBP: ffff880111747c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000069dd8358 R11: 1ffffffff0759723 R12: 0000000000000000 R13: ffff88011a7e4780 R14: 0000000000000027 R15: 0000000000000000 FS: 00007fc738404700(0000) GS:ffff88011af00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc737fdfb10 CR3: 0000000118087000 CR4: 00000000000006e0 Stack: 0000000000000200 ffff880111747bd8 ffffffff810ee611 ffff880119f1f220 ffff880119f1f4f8 ffff880119f1f4f0 ffff88011a7e4780 ffff880119f1f232 ffff880119f1f220 ffff880111747d58 ffffffff82bca542 0000000000000000 Call Trace: [] irda_connect+0x562/0x1190 [] SYSC_connect+0x202/0x2a0 [] SyS_connect+0x9/0x10 [] do_syscall_64+0x19c/0x410 [] entry_SYSCALL64_slow_path+0x25/0x25 Code: 41 89 ca 48 89 e5 41 57 41 56 41 55 41 54 41 89 d7 53 48 89 fb 48 83 c7 48 48 89 fa 41 89 f6 48 c1 ea 03 48 83 ec 20 4c 8b 65 10 <0f> b6 04 02 84 c0 74 08 84 c0 0f 8e 4c 04 00 00 80 7b 48 00 74 RIP [] irttp_connect_request+0x36/0x710 RSP ---[ end trace 4cda2588bc055b30 ]--- The problem is that irda_open_tsap() can fail and leave self->tsap = NULL, and then irttp_connect_request() almost immediately dereferences it. Cc: stable@vger.kernel.org Signed-off-by: Vegard Nossum Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: Prevent soft lockup when sctp_accept() is called during a timeout event

2016-08-16T07:29:02+00:00

commit 635682a14427d241bab7bbdeebb48a7d7b91638e upstream. A case can occur when sctp_accept() is called by the user during a heartbeat timeout event after the 4-way handshake. Since sctp_assoc_migrate() changes both assoc->base.sk and assoc->ep, the bh_sock_lock in sctp_generate_heartbeat_event() will be taken with the listening socket but released with the new association socket. The result is a deadlock on any future attempts to take the listening socket lock. Note that this race can occur with other SCTP timeouts that take the bh_lock_sock() in the event sctp_accept() is called. BUG: soft lockup - CPU#9 stuck for 67s! [swapper:0] ... RIP: 0010:[] [] _spin_lock+0x1e/0x30 RSP: 0018:ffff880028323b20 EFLAGS: 00000206 RAX: 0000000000000002 RBX: ffff880028323b20 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff880028323be0 RDI: ffff8804632c4b48 RBP: ffffffff8100bb93 R08: 0000000000000000 R09: 0000000000000000 R10: ffff880610662280 R11: 0000000000000100 R12: ffff880028323aa0 R13: ffff8804383c3880 R14: ffff880028323a90 R15: ffffffff81534225 FS: 0000000000000000(0000) GS:ffff880028320000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 00000000006df528 CR3: 0000000001a85000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process swapper (pid: 0, threadinfo ffff880616b70000, task ffff880616b6cab0) Stack: ffff880028323c40 ffffffffa01c2582 ffff880614cfb020 0000000000000000 0100000000000000 00000014383a6c44 ffff8804383c3880 ffff880614e93c00 ffff880614e93c00 0000000000000000 ffff8804632c4b00 ffff8804383c38b8 Call Trace: [] ? sctp_rcv+0x492/0xa10 [sctp] [] ? nf_iterate+0x69/0xb0 [] ? ip_local_deliver_finish+0x0/0x2d0 [] ? nf_hook_slow+0x76/0x120 [] ? ip_local_deliver_finish+0x0/0x2d0 [] ? ip_local_deliver_finish+0xdd/0x2d0 [] ? ip_local_deliver+0x98/0xa0 [] ? ip_rcv_finish+0x12d/0x440 [] ? ip_rcv+0x275/0x350 [] ? __netif_receive_skb+0x4ab/0x750 ... With lockdep debugging: ===================================== [ BUG: bad unlock balance detected! ] ------------------------------------- CslRx/12087 is trying to release lock (slock-AF_INET) at: [] sctp_generate_timeout_event+0x40/0xe0 [sctp] but there are no more locks to release! other info that might help us debug this: 2 locks held by CslRx/12087: #0: (&asoc->timers[i]){+.-...}, at: [] run_timer_softirq+0x16f/0x3e0 #1: (slock-AF_INET){+.-...}, at: [] sctp_generate_timeout_event+0x23/0xe0 [sctp] Ensure the socket taken is also the same one that is released by saving a copy of the socket before entering the timeout event critical section. Signed-off-by: Karl Heiss Signed-off-by: David S. Miller Cc: Ben Hutchings Signed-off-by: Luis Henriques (cherry picked from commit 013dd9e038723bbd2aa67be51847384b75be8253) Signed-off-by: Chas Williams <3chas3@gmail.com> Signed-off-by: Greg Kroah-Hartman

libceph: apply new_state before new_up_client on incrementals

2016-08-10T08:21:04+00:00

commit 930c532869774ebf8af9efe9484c597f896a7d46 upstream. Currently, osd_weight and osd_state fields are updated in the encoding order. This is wrong, because an incremental map may look like e.g. new_up_client: { osd=6, addr=... } # set osd_state and addr new_state: { osd=6, xorstate=EXISTS } # clear osd_state Suppose osd6's current osd_state is EXISTS (i.e. osd6 is down). After applying new_up_client, osd_state is changed to EXISTS | UP. Carrying on with the new_state update, we flip EXISTS and leave osd6 in a weird "!EXISTS but UP" state. A non-existent OSD is considered down by the mapping code 2087 for (i = 0; i < pg->pg_temp.len; i++) { 2088 if (ceph_osd_is_down(osdmap, pg->pg_temp.osds[i])) { 2089 if (ceph_can_shift_osds(pi)) 2090 continue; 2091 2092 temp->osds[temp->size++] = CRUSH_ITEM_NONE; and so requests get directed to the second OSD in the set instead of the first, resulting in OSD-side errors like: [WRN] : client.4239 192.168.122.21:0/2444980242 misdirected client.4239.1:2827 pg 2.5df899f2 to osd.4 not [1,4,6] in e680/680 and hung rbds on the client: [ 493.566367] rbd: rbd0: write 400000 at 11cc00000 (0) [ 493.566805] rbd: rbd0: result -6 xferred 400000 [ 493.567011] blk_update_request: I/O error, dev rbd0, sector 9330688 The fix is to decouple application from the decoding and: - apply new_weight first - apply new_state before new_up_client - twiddle osd_state flags if marking in - clear out some of the state if osd is destroyed Fixes: http://tracker.ceph.com/issues/14901 Signed-off-by: Ilya Dryomov Reviewed-by: Josh Durgin [idryomov@gmail.com: backport to 3.10-3.14: strip primary-affinity] Signed-off-by: Greg Kroah-Hartman

mac80211: mesh: flush mesh paths unconditionally

2016-07-27T16:55:48+00:00

commit fe7a7c57629e8dcbc0e297363a9b2366d67a6dc5 upstream. Currently, the mesh paths associated with a nexthop station are cleaned up in the following code path: __sta_info_destroy_part1 synchronize_net() __sta_info_destroy_part2 -> cleanup_single_sta -> mesh_sta_cleanup -> mesh_plink_deactivate -> mesh_path_flush_by_nexthop However, there are a couple of problems here: 1) the paths aren't flushed at all if the MPM is running in userspace (e.g. when using wpa_supplicant or authsae) 2) there is no synchronize_rcu between removing the path and readers accessing the nexthop, which means the following race is possible: CPU0 CPU1 ~~~~ ~~~~ sta_info_destroy_part1() synchronize_net() rcu_read_lock() mesh_nexthop_resolve() mpath = mesh_path_lookup() [...] -> mesh_path_flush_by_nexthop() sta = rcu_dereference( mpath->next_hop) kfree(sta) access sta <-- CRASH Fix both of these by unconditionally flushing paths before destroying the sta, and by adding a synchronize_net() after path flush to ensure no active readers can still dereference the sta. Fixes this crash: [ 348.529295] BUG: unable to handle kernel paging request at 00020040 [ 348.530014] IP: [] ieee80211_mps_set_frame_flags+0x40/0xaa [mac80211] [ 348.530014] *pde = 00000000 [ 348.530014] Oops: 0000 [#1] PREEMPT [ 348.530014] Modules linked in: drbg ansi_cprng ctr ccm ppp_generic slhc ipt_MASQUERADE nf_nat_masquerade_ipv4 8021q ] [ 348.530014] CPU: 0 PID: 20597 Comm: wget Tainted: G O 4.6.0-rc5-wt=V1 #1 [ 348.530014] Hardware name: To Be Filled By O.E.M./To be filled by O.E.M., BIOS 080016 11/07/2014 [ 348.530014] task: f64fa280 ti: f4f9c000 task.ti: f4f9c000 [ 348.530014] EIP: 0060:[] EFLAGS: 00010246 CPU: 0 [ 348.530014] EIP is at ieee80211_mps_set_frame_flags+0x40/0xaa [mac80211] [ 348.530014] EAX: f4ce63e0 EBX: 00000088 ECX: f3788416 EDX: 00020008 [ 348.530014] ESI: 00000000 EDI: 00000088 EBP: f6409a4c ESP: f6409a40 [ 348.530014] DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 [ 348.530014] CR0: 80050033 CR2: 00020040 CR3: 33190000 CR4: 00000690 [ 348.530014] Stack: [ 348.530014] 00000000 f4ce63e0 f5f9bd80 f6409a64 f9291d80 0000ce67 f5d51e00 f4ce63e0 [ 348.530014] f3788416 f6409a80 f9291dc1 f4ce8320 f4ce63e0 f5d51e00 f4ce63e0 f4ce8320 [ 348.530014] f6409a98 f9277f6f 00000000 00000000 0000007c 00000000 f6409b2c f9278dd1 [ 348.530014] Call Trace: [ 348.530014] [] mesh_nexthop_lookup+0xbb/0xc8 [mac80211] [ 348.530014] [] mesh_nexthop_resolve+0x34/0xd8 [mac80211] [ 348.530014] [] ieee80211_xmit+0x92/0xc1 [mac80211] [ 348.530014] [] __ieee80211_subif_start_xmit+0x807/0x83c [mac80211] [ 348.530014] [] ? sch_direct_xmit+0xd7/0x1b3 [ 348.530014] [] ? __local_bh_enable_ip+0x5d/0x7b [ 348.530014] [] ? nf_nat_ipv4_out+0x4c/0xd0 [nf_nat_ipv4] [ 348.530014] [] ? iptable_nat_ipv4_fn+0xf/0xf [iptable_nat] [ 348.530014] [] ? netif_skb_features+0x14d/0x30a [ 348.530014] [] ieee80211_subif_start_xmit+0xa/0xe [mac80211] [ 348.530014] [] dev_hard_start_xmit+0x1f8/0x267 [ 348.530014] [] ? validate_xmit_skb.isra.120.part.121+0x10/0x253 [ 348.530014] [] sch_direct_xmit+0x8b/0x1b3 [ 348.530014] [] __dev_queue_xmit+0x2c8/0x513 [ 348.530014] [] dev_queue_xmit+0xa/0xc [ 348.530014] [] batadv_send_skb_packet+0xd6/0xec [batman_adv] [ 348.530014] [] batadv_send_unicast_skb+0x15/0x4a [batman_adv] [ 348.530014] [] batadv_dat_send_data+0x27e/0x310 [batman_adv] [ 348.530014] [] ? batadv_tt_global_hash_find.isra.11+0x8/0xa [batman_adv] [ 348.530014] [] batadv_dat_snoop_outgoing_arp_request+0x208/0x23d [batman_adv] [ 348.530014] [] batadv_interface_tx+0x206/0x385 [batman_adv] [ 348.530014] [] dev_hard_start_xmit+0x1f8/0x267 [ 348.530014] [] ? validate_xmit_skb.isra.120.part.121+0x10/0x253 [ 348.530014] [] sch_direct_xmit+0x8b/0x1b3 [ 348.530014] [] __dev_queue_xmit+0x2c8/0x513 [ 348.530014] [] ? igb_xmit_frame+0x57/0x72 [igb] [ 348.530014] [] dev_queue_xmit+0xa/0xc [ 348.530014] [] br_dev_queue_push_xmit+0xeb/0xfb [bridge] [ 348.530014] [] br_forward_finish+0x29/0x74 [bridge] [ 348.530014] [] ? deliver_clone+0x3b/0x3b [bridge] [ 348.530014] [] __br_forward+0x89/0xe7 [bridge] [ 348.530014] [] ? br_dev_queue_push_xmit+0xfb/0xfb [bridge] [ 348.530014] [] deliver_clone+0x34/0x3b [bridge] [ 348.530014] [] ? br_flood+0x95/0x95 [bridge] [ 348.530014] [] br_flood+0x77/0x95 [bridge] [ 348.530014] [] br_flood_forward+0x13/0x1a [bridge] [ 348.530014] [] ? br_flood+0x95/0x95 [bridge] [ 348.530014] [] br_handle_frame_finish+0x392/0x3db [bridge] [ 348.530014] [] ? nf_iterate+0x2b/0x6b [ 348.530014] [] br_handle_frame+0x1e6/0x240 [bridge] [ 348.530014] [] ? br_handle_local_finish+0x6a/0x6a [bridge] [ 348.530014] [] __netif_receive_skb_core+0x43a/0x66b [ 348.530014] [] ? br_handle_frame_finish+0x3db/0x3db [bridge] [ 348.530014] [] ? resched_curr+0x19/0x37 [ 348.530014] [] ? check_preempt_wakeup+0xbf/0xfe [ 348.530014] [] ? ktime_get_with_offset+0x5c/0xfc [ 348.530014] [] __netif_receive_skb+0x47/0x55 [ 348.530014] [] netif_receive_skb_internal+0x40/0x5a [ 348.530014] [] napi_gro_receive+0x3a/0x94 [ 348.530014] [] igb_poll+0x6fd/0x9ad [igb] [ 348.530014] [] ? swake_up_locked+0x14/0x26 [ 348.530014] [] net_rx_action+0xde/0x250 [ 348.530014] [] __do_softirq+0x8a/0x163 [ 348.530014] [] ? __hrtimer_tasklet_trampoline+0x19/0x19 [ 348.530014] [] do_softirq_own_stack+0x26/0x2c [ 348.530014] [ 348.530014] [] irq_exit+0x31/0x6f [ 348.530014] [] do_IRQ+0x8d/0xa0 [ 348.530014] [] common_interrupt+0x2c/0x40 [ 348.530014] Code: e7 8c 00 66 81 ff 88 00 75 12 85 d2 75 0e b2 c3 b8 83 e9 29 f9 e8 a7 5f f9 c6 eb 74 66 81 e3 8c 005 [ 348.530014] EIP: [] ieee80211_mps_set_frame_flags+0x40/0xaa [mac80211] SS:ESP 0068:f6409a40 [ 348.530014] CR2: 0000000000020040 [ 348.530014] ---[ end trace 48556ac26779732e ]--- [ 348.530014] Kernel panic - not syncing: Fatal exception in interrupt [ 348.530014] Kernel Offset: disabled Reported-by: Fred Veldini Tested-by: Fred Veldini Signed-off-by: Bob Copeland Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman

ipmr/ip6mr: Initialize the last assert time of mfc entries.

2016-07-27T16:55:47+00:00

[ Upstream commit 70a0dec45174c976c64b4c8c1d0898581f759948 ] This fixes wrong-interface signaling on 32-bit platforms for entries created when jiffies > 2^31 + MFC_ASSERT_THRESH. Signed-off-by: Tom Goff Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sit: correct IP protocol used in ipip6_err

2016-07-27T16:55:47+00:00

[ Upstream commit d5d8760b78d0cfafe292f965f599988138b06a70 ] Since 32b8a8e59c9c ("sit: add IPv4 over IPv4 support") ipip6_err() may be called for packets whose IP protocol is IPPROTO_IPIP as well as those whose IP protocol is IPPROTO_IPV6. In the case of IPPROTO_IPIP packets the correct protocol value is not passed to ipv4_update_pmtu() or ipv4_redirect(). This patch resolves this problem by using the IP protocol of the packet rather than a hard-coded value. This appears to be consistent with the usage of the protocol of a packet by icmp_socket_deliver() the caller of ipip6_err(). I was able to exercise the redirect case by using a setup where an ICMP redirect was received for the destination of the encapsulated packet. However, it appears that although incorrect the protocol field is not used in this case and thus no problem manifests. On inspection it does not appear that a problem will manifest in the fragmentation needed/update pmtu case either. In short I believe this is a cosmetic fix. None the less, the use of IPPROTO_IPV6 seems wrong and confusing. Reviewed-by: Dinan Gunawardena Signed-off-by: Simon Horman Acked-by: YOSHIFUJI Hideaki Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netfilter: x_tables: introduce and use xt_copy_counters_from_user

2016-06-24T17:15:31+00:00

commit d7591f0c41ce3e67600a982bab6989ef0f07b3ce upstream The three variants use same copy&pasted code, condense this into a helper and use that. Make sure info.name is 0-terminated. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

Revert "netfilter: ensure number of counters is >0 in do_replace()"

2016-06-24T17:15:31+00:00

commit d26e2c9ffa385dd1b646f43c1397ba12af9ed431 upstream. This partially reverts commit 1086bbe97a07 ("netfilter: ensure number of counters is >0 in do_replace()") in net/bridge/netfilter/ebtables.c. Setting rules with ebtables does not work any more with 1086bbe97a07 place. There is an error message and no rules set in the end. e.g. ~# ebtables -t nat -A POSTROUTING --src 12:34:56:78:9a:bc -j DROP Unable to update the kernel. Two possible causes: 1. Multiple ebtables programs were executing simultaneously. The ebtables userspace tool doesn't by default support multiple ebtables programs running Reverting the ebtables part of 1086bbe97a07 makes this work again. Signed-off-by: Bernhard Thaler Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman