Skip to content

L
linux
Switch branch/tag
  1. 17 Dec, 2018 10 commits
    • Edward Cree's avatar
      net: use skb_list_del_init() to remove from RX sublists · 7fafda16
      Edward Cree authored 
      [ Upstream commit 22f6bbb7 ]

list_del() leaves the skb->next pointer poisoned, which can then lead to
 a crash in e.g. OVS forwarding.  For example, setting up an OVS VXLAN
 forwarding bridge on sfc as per:

========
$ ovs-vsctl show
5dfd9c47-f04b-4aaa-aa96-4fbb0a522a30
    Bridge "br0"
        Port "br0"
            Interface "br0"
                type: internal
        Port "enp6s0f0"
            Interface "enp6s0f0"
        Port "vxlan0"
            Interface "vxlan0"
                type: vxlan
                options: {key="1", local_ip="10.0.0.5", remote_ip="10.0.0.4"}
    ovs_version: "2.5.0"
========
(where 10.0.0.5 is an address on enp6s0f1)
and sending traffic across it will lead to the following panic:
========
general protection fault: 0000 [#1] SMP PTI
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.20.0-rc3-ehc+ #701
Hardware name: Dell Inc. PowerEdge R710/0M233H, BIOS 6.4.0 07/23/2013
RIP: 0010:dev_hard_start_xmit+0x38/0x200
Code: 53 48 89 fb 48 83 ec 20 48 85 ff 48 89 54 24 08 48 89 4c 24 18 0f 84 ab 01 00 00 48 8d 86 90 00 00 00 48 89 f5 48 89 44 24 10 <4c> 8b 33 48 c7 03 00 00 00 00 48 8b 05 c7 d1 b3 00 4d 85 f6 0f 95
RSP: 0018:ffff888627b437e0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: dead000000000100 RCX: ffff88862279c000
RDX: ffff888614a342c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888618a88000 R08: 0000000000000001 R09: 00000000000003e8
R10: 0000000000000000 R11: ffff888614a34140 R12: 0000000000000000
R13: 0000000000000062 R14: dead000000000100 R15: ffff888616430000
FS:  0000000000000000(0000) GS:ffff888627b40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6d2bc6d000 CR3: 000000000200a000 CR4: 00000000000006e0
Call Trace:
 <IRQ>
 __dev_queue_xmit+0x623/0x870
 ? masked_flow_lookup+0xf7/0x220 [openvswitch]
 ? ep_poll_callback+0x101/0x310
 do_execute_actions+0xaba/0xaf0 [openvswitch]
 ? __wake_up_common+0x8a/0x150
 ? __wake_up_common_lock+0x87/0xc0
 ? queue_userspace_packet+0x31c/0x5b0 [openvswitch]
 ovs_execute_actions+0x47/0x120 [openvswitch]
 ovs_dp_process_packet+0x7d/0x110 [openvswitch]
 ovs_vport_receive+0x6e/0xd0 [openvswitch]
 ? dst_alloc+0x64/0x90
 ? rt_dst_alloc+0x50/0xd0
 ? ip_route_input_slow+0x19a/0x9a0
 ? __udp_enqueue_schedule_skb+0x198/0x1b0
 ? __udp4_lib_rcv+0x856/0xa30
 ? __udp4_lib_rcv+0x856/0xa30
 ? cpumask_next_and+0x19/0x20
 ? find_busiest_group+0x12d/0xcd0
 netdev_frame_hook+0xce/0x150 [openvswitch]
 __netif_receive_skb_core+0x205/0xae0
 __netif_receive_skb_list_core+0x11e/0x220
 netif_receive_skb_list+0x203/0x460
 ? __efx_rx_packet+0x335/0x5e0 [sfc]
 efx_poll+0x182/0x320 [sfc]
 net_rx_action+0x294/0x3c0
 __do_softirq+0xca/0x297
 irq_exit+0xa6/0xb0
 do_IRQ+0x54/0xd0
 common_interrupt+0xf/0xf
 </IRQ>
========
So, in all listified-receive handling, instead pull skbs off the lists with
 skb_list_del_init().

Fixes: 9af86f93 ("net: core: fix use-after-free in __netif_receive_skb_list_core")
Fixes: 7da517a3 ("net: core: Another step of skb receive list processing")
Fixes: a4ca8b7d ("net: ipv4: fix drop handling in ip_list_rcv() and ip_list_rcv_finish()")
Fixes: d8269e2c ("net: ipv6: listify ipv6_rcv() and ip6_rcv_finish()")
Signed-off-by: default avatarEdward Cree <ecree@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7fafda16
    • Christoph Paasch's avatar
      net: Prevent invalid access to skb->prev in __qdisc_drop_all · 16218638
      Christoph Paasch authored 
      [ Upstream commit 9410d386 ]

__qdisc_drop_all() accesses skb->prev to get to the tail of the
segment-list.

With commit 68d2f84a ("net: gro: properly remove skb from list")
the skb-list handling has been changed to set skb->next to NULL and set
the list-poison on skb->prev.

With that change, __qdisc_drop_all() will panic when it tries to
dereference skb->prev.

Since commit 992cba7e ("net: Add and use skb_list_del_init().")
__list_del_entry is used, leaving skb->prev unchanged (thus,
pointing to the list-head if it's the first skb of the list).
This will make __qdisc_drop_all modify the next-pointer of the list-head
and result in a panic later on:

[   34.501053] general protection fault: 0000 [#1] SMP KASAN PTI
[   34.501968] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.20.0-rc2.mptcp #108
[   34.502887] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.5.1 01/01/2011
[   34.504074] RIP: 0010:dev_gro_receive+0x343/0x1f90
[   34.504751] Code: e0 48 c1 e8 03 42 80 3c 30 00 0f 85 4a 1c 00 00 4d 8b 24 24 4c 39 65 d0 0f 84 0a 04 00 00 49 8d 7c 24 38 48 89 f8 48 c1 e8 03 <42> 0f b6 04 30 84 c0 74 08 3c 04
[   34.507060] RSP: 0018:ffff8883af507930 EFLAGS: 00010202
[   34.507761] RAX: 0000000000000007 RBX: ffff8883970b2c80 RCX: 1ffff11072e165a6
[   34.508640] RDX: 1ffff11075867008 RSI: ffff8883ac338040 RDI: 0000000000000038
[   34.509493] RBP: ffff8883af5079d0 R08: ffff8883970b2d40 R09: 0000000000000062
[   34.510346] R10: 0000000000000034 R11: 0000000000000000 R12: 0000000000000000
[   34.511215] R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8883ac338008
[   34.512082] FS:  0000000000000000(0000) GS:ffff8883af500000(0000) knlGS:0000000000000000
[   34.513036] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   34.513741] CR2: 000055ccc3e9d020 CR3: 00000003abf32000 CR4: 00000000000006e0
[   34.514593] Call Trace:
[   34.514893]  <IRQ>
[   34.515157]  napi_gro_receive+0x93/0x150
[   34.515632]  receive_buf+0x893/0x3700
[   34.516094]  ? __netif_receive_skb+0x1f/0x1a0
[   34.516629]  ? virtnet_probe+0x1b40/0x1b40
[   34.517153]  ? __stable_node_chain+0x4d0/0x850
[   34.517684]  ? kfree+0x9a/0x180
[   34.518067]  ? __kasan_slab_free+0x171/0x190
[   34.518582]  ? detach_buf+0x1df/0x650
[   34.519061]  ? lapic_next_event+0x5a/0x90
[   34.519539]  ? virtqueue_get_buf_ctx+0x280/0x7f0
[   34.520093]  virtnet_poll+0x2df/0xd60
[   34.520533]  ? receive_buf+0x3700/0x3700
[   34.521027]  ? qdisc_watchdog_schedule_ns+0xd5/0x140
[   34.521631]  ? htb_dequeue+0x1817/0x25f0
[   34.522107]  ? sch_direct_xmit+0x142/0xf30
[   34.522595]  ? virtqueue_napi_schedule+0x26/0x30
[   34.523155]  net_rx_action+0x2f6/0xc50
[   34.523601]  ? napi_complete_done+0x2f0/0x2f0
[   34.524126]  ? kasan_check_read+0x11/0x20
[   34.524608]  ? _raw_spin_lock+0x7d/0xd0
[   34.525070]  ? _raw_spin_lock_bh+0xd0/0xd0
[   34.525563]  ? kvm_guest_apic_eoi_write+0x6b/0x80
[   34.526130]  ? apic_ack_irq+0x9e/0xe0
[   34.526567]  __do_softirq+0x188/0x4b5
[   34.527015]  irq_exit+0x151/0x180
[   34.527417]  do_IRQ+0xdb/0x150
[   34.527783]  common_interrupt+0xf/0xf
[   34.528223]  </IRQ>

This patch makes sure that skb->prev is set to NULL when entering
netem_enqueue.

Cc: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: 68d2f84a ("net: gro: properly remove skb from list")
Suggested-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarChristoph Paasch <cpaasch@apple.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      16218638
    • Heiner Kallweit's avatar
      net: phy: don't allow __set_phy_supported to add unsupported modes · ac1fb97e
      Heiner Kallweit authored 
      [ Upstream commit d2a36971 ]

Currently __set_phy_supported allows to add modes w/o checking whether
the PHY supports them. This is wrong, it should never add modes but
only remove modes we don't want to support.

The commit marked as fixed didn't do anything wrong, it just copied
existing functionality to the helper which is being fixed now.

Fixes: f3a6bd39 ("phylib: Add phy_set_max_speed helper")
Signed-off-by: default avatarHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ac1fb97e
    • Eran Ben Elisha's avatar
      net/mlx4_en: Change min MTU size to ETH_MIN_MTU · 70727c00
      Eran Ben Elisha authored 
      [ Upstream commit 24be19e4 ]

NIC driver minimal MTU size shall be set to ETH_MIN_MTU, as defined in
the RFC791 and in the network stack. Remove old mlx4_en only define for
it, which was set to wrong value.

Fixes: b80f71f5 ("ethernet/mellanox: use core min/max MTU checking")
Signed-off-by: default avatarEran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: default avatarTariq Toukan <tariqt@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      70727c00
    • Tarick Bedeir's avatar
      net/mlx4_core: Correctly set PFC param if global pause is turned off. · 1fa276e9
      Tarick Bedeir authored 
      [ Upstream commit bd5122cd ]

rx_ppp and tx_ppp can be set between 0 and 255, so don't clamp to 1.

Fixes: 6e8814ce ("net/mlx4_en: Fix mixed PFC and Global pause user control requests")
Signed-off-by: default avatarTarick Bedeir <tarick@google.com>
Reviewed-by: default avatarEran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1fa276e9
    • Su Yanjun's avatar
      net: 8139cp: fix a BUG triggered by changing mtu with network traffic · ec5d7ced
      Su Yanjun authored 
      [ Upstream commit a5d4a892 ]

When changing mtu many times with traffic, a bug is triggered:

[ 1035.684037] kernel BUG at lib/dynamic_queue_limits.c:26!
[ 1035.684042] invalid opcode: 0000 [#1] SMP
[ 1035.684049] Modules linked in: loop binfmt_misc 8139cp(OE) macsec
tcp_diag udp_diag inet_diag unix_diag af_packet_diag netlink_diag tcp_lp
fuse uinput xt_CHECKSUM iptable_mangle ipt_MASQUERADE
nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4
nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun
bridge stp llc ebtable_filter ebtables ip6table_filter devlink
ip6_tables iptable_filter sunrpc snd_hda_codec_generic snd_hda_intel
snd_hda_codec snd_hda_core snd_hwdep ppdev snd_seq iosf_mbi crc32_pclmul
parport_pc snd_seq_device ghash_clmulni_intel parport snd_pcm
aesni_intel joydev lrw snd_timer virtio_balloon sg gf128mul glue_helper
ablk_helper cryptd snd soundcore i2c_piix4 pcspkr ip_tables xfs
libcrc32c sr_mod sd_mod cdrom crc_t10dif crct10dif_generic ata_generic
[ 1035.684102]  pata_acpi virtio_console qxl drm_kms_helper syscopyarea
sysfillrect sysimgblt floppy fb_sys_fops crct10dif_pclmul
crct10dif_common ttm crc32c_intel serio_raw ata_piix drm libata 8139too
virtio_pci drm_panel_orientation_quirks virtio_ring virtio mii dm_mirror
dm_region_hash dm_log dm_mod [last unloaded: 8139cp]
[ 1035.684132] CPU: 9 PID: 25140 Comm: if-mtu-change Kdump: loaded
Tainted: G           OE  ------------ T 3.10.0-957.el7.x86_64 #1
[ 1035.684134] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 1035.684136] task: ffff8f59b1f5a080 ti: ffff8f5a2e32c000 task.ti:
ffff8f5a2e32c000
[ 1035.684149] RIP: 0010:[<ffffffffba3a40d0>]  [<ffffffffba3a40d0>]
dql_completed+0x180/0x190
[ 1035.684162] RSP: 0000:ffff8f5a75483e50  EFLAGS: 00010093
[ 1035.684162] RAX: 00000000000000c2 RBX: ffff8f5a6f91c000 RCX:
0000000000000000
[ 1035.684162] RDX: 0000000000000000 RSI: 0000000000000184 RDI:
ffff8f599fea3ec0
[ 1035.684162] RBP: ffff8f5a75483ea8 R08: 00000000000000c2 R09:
0000000000000000
[ 1035.684162] R10: 00000000000616ef R11: ffff8f5a75483b56 R12:
ffff8f599fea3e00
[ 1035.684162] R13: 0000000000000001 R14: 0000000000000000 R15:
0000000000000184
[ 1035.684162] FS:  00007fa8434de740(0000) GS:ffff8f5a75480000(0000)
knlGS:0000000000000000
[ 1035.684162] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1035.684162] CR2: 00000000004305d0 CR3: 000000024eb66000 CR4:
00000000001406e0
[ 1035.684162] Call Trace:
[ 1035.684162]  <IRQ>
[ 1035.684162]  [<ffffffffc08cbaf8>] ? cp_interrupt+0x478/0x580 [8139cp]
[ 1035.684162]  [<ffffffffba14a294>]
__handle_irq_event_percpu+0x44/0x1c0
[ 1035.684162]  [<ffffffffba14a442>] handle_irq_event_percpu+0x32/0x80
[ 1035.684162]  [<ffffffffba14a4cc>] handle_irq_event+0x3c/0x60
[ 1035.684162]  [<ffffffffba14db29>] handle_fasteoi_irq+0x59/0x110
[ 1035.684162]  [<ffffffffba02e554>] handle_irq+0xe4/0x1a0
[ 1035.684162]  [<ffffffffba7795dd>] do_IRQ+0x4d/0xf0
[ 1035.684162]  [<ffffffffba76b362>] common_interrupt+0x162/0x162
[ 1035.684162]  <EOI>
[ 1035.684162]  [<ffffffffba0c2ae4>] ? __wake_up_bit+0x24/0x70
[ 1035.684162]  [<ffffffffba1e46f5>] ? do_set_pte+0xd5/0x120
[ 1035.684162]  [<ffffffffba1b64fb>] unlock_page+0x2b/0x30
[ 1035.684162]  [<ffffffffba1e4879>] do_read_fault.isra.61+0x139/0x1b0
[ 1035.684162]  [<ffffffffba1e9134>] handle_pte_fault+0x2f4/0xd10
[ 1035.684162]  [<ffffffffba1ebc6d>] handle_mm_fault+0x39d/0x9b0
[ 1035.684162]  [<ffffffffba76f5e3>] __do_page_fault+0x203/0x500
[ 1035.684162]  [<ffffffffba76f9c6>] trace_do_page_fault+0x56/0x150
[ 1035.684162]  [<ffffffffba76ef42>] do_async_page_fault+0x22/0xf0
[ 1035.684162]  [<ffffffffba76b788>] async_page_fault+0x28/0x30
[ 1035.684162] Code: 54 c7 47 54 ff ff ff ff 44 0f 49 ce 48 8b 35 48 2f
9c 00 48 89 77 58 e9 fe fe ff ff 0f 1f 80 00 00 00 00 41 89 d1 e9 ef fe
ff ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 55 8d 42 ff 48
[ 1035.684162] RIP  [<ffffffffba3a40d0>] dql_completed+0x180/0x190
[ 1035.684162]  RSP <ffff8f5a75483e50>

It's not the same as in 7fe0ee09 patch described.
As 8139cp uses shared irq mode, other device irq will trigger
cp_interrupt to execute.

cp_change_mtu
 -> cp_close
 -> cp_open

In cp_close routine  just before free_irq(), some interrupt may occur.
In my environment, cp_interrupt exectutes and IntrStatus is 0x4,
exactly TxOk. That will cause cp_tx to wake device queue.

As device queue is started, cp_start_xmit and cp_open will run at same
time which will cause kernel BUG.

For example:
[#] for tx descriptor

At start:

[#][#][#]
num_queued=3

After cp_init_hw->cp_start_hw->netdev_reset_queue:

[#][#][#]
num_queued=0

When 8139cp starts to work then cp_tx will check
num_queued mismatchs the complete_bytes.

The patch will check IntrMask before check IntrStatus in cp_interrupt.
When 8139cp interrupt is disabled, just return.
Signed-off-by: default avatarSu Yanjun <suyj.fnst@cn.fujitsu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ec5d7ced
    • Shmulik Ladkani's avatar
      ipv6: sr: properly initialize flowi6 prior passing to ip6_route_output · c4ec6a9a
      Shmulik Ladkani authored 
      [ Upstream commit 1b4e5ad5 ]

In 'seg6_output', stack variable 'struct flowi6 fl6' was missing
initialization.

Fixes: 6c8702c6 ("ipv6: sr: add support for SRH encapsulation and injection with lwtunnels")
Signed-off-by: default avatarShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c4ec6a9a
    • Stefano Brivio's avatar
      neighbour: Avoid writing before skb->head in neigh_hh_output() · 0e96b903
      Stefano Brivio authored 
      [ Upstream commit e6ac64d4 ]

While skb_push() makes the kernel panic if the skb headroom is less than
the unaligned hardware header size, it will proceed normally in case we
copy more than that because of alignment, and we'll silently corrupt
adjacent slabs.

In the case fixed by the previous patch,
"ipv6: Check available headroom in ip6_xmit() even without options", we
end up in neigh_hh_output() with 14 bytes headroom, 14 bytes hardware
header and write 16 bytes, starting 2 bytes before the allocated buffer.

Always check we're not writing before skb->head and, if the headroom is
not enough, warn and drop the packet.

v2:
 - instead of panicking with BUG_ON(), WARN_ON_ONCE() and drop the packet
   (Eric Dumazet)
 - if we avoid the panic, though, we need to explicitly check the headroom
   before the memcpy(), otherwise we'll have corrupted slabs on a running
   kernel, after we warn
 - use __skb_push() instead of skb_push(), as the headroom check is
   already implemented here explicitly (Eric Dumazet)
Signed-off-by: default avatarStefano Brivio <sbrivio@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0e96b903
    • Stefano Brivio's avatar
      ipv6: Check available headroom in ip6_xmit() even without options · fd018cb3
      Stefano Brivio authored 
      [ Upstream commit 66033f47 ]

Even if we send an IPv6 packet without options, MAX_HEADER might not be
enough to account for the additional headroom required by alignment of
hardware headers.

On a configuration without HYPERV_NET, WLAN, AX25, and with IPV6_TUNNEL,
sending short SCTP packets over IPv4 over L2TP over IPv6, we start with
100 bytes of allocated headroom in sctp_packet_transmit(), end up with 54
bytes after l2tp_xmit_skb(), and 14 bytes in ip6_finish_output2().

Those would be enough to append our 14 bytes header, but we're going to
align that to 16 bytes, and write 2 bytes out of the allocated slab in
neigh_hh_output().

KASan says:

[  264.967848] ==================================================================
[  264.967861] BUG: KASAN: slab-out-of-bounds in ip6_finish_output2+0x1aec/0x1c70
[  264.967866] Write of size 16 at addr 000000006af1c7fe by task netperf/6201
[  264.967870]
[  264.967876] CPU: 0 PID: 6201 Comm: netperf Not tainted 4.20.0-rc4+ #1
[  264.967881] Hardware name: IBM 2827 H43 400 (z/VM 6.4.0)
[  264.967887] Call Trace:
[  264.967896] ([<00000000001347d6>] show_stack+0x56/0xa0)
[  264.967903]  [<00000000017e379c>] dump_stack+0x23c/0x290
[  264.967912]  [<00000000007bc594>] print_address_description+0xf4/0x290
[  264.967919]  [<00000000007bc8fc>] kasan_report+0x13c/0x240
[  264.967927]  [<000000000162f5e4>] ip6_finish_output2+0x1aec/0x1c70
[  264.967935]  [<000000000163f890>] ip6_finish_output+0x430/0x7f0
[  264.967943]  [<000000000163fe44>] ip6_output+0x1f4/0x580
[  264.967953]  [<000000000163882a>] ip6_xmit+0xfea/0x1ce8
[  264.967963]  [<00000000017396e2>] inet6_csk_xmit+0x282/0x3f8
[  264.968033]  [<000003ff805fb0ba>] l2tp_xmit_skb+0xe02/0x13e0 [l2tp_core]
[  264.968037]  [<000003ff80631192>] l2tp_eth_dev_xmit+0xda/0x150 [l2tp_eth]
[  264.968041]  [<0000000001220020>] dev_hard_start_xmit+0x268/0x928
[  264.968069]  [<0000000001330e8e>] sch_direct_xmit+0x7ae/0x1350
[  264.968071]  [<000000000122359c>] __dev_queue_xmit+0x2b7c/0x3478
[  264.968075]  [<00000000013d2862>] ip_finish_output2+0xce2/0x11a0
[  264.968078]  [<00000000013d9b14>] ip_finish_output+0x56c/0x8c8
[  264.968081]  [<00000000013ddd1e>] ip_output+0x226/0x4c0
[  264.968083]  [<00000000013dbd6c>] __ip_queue_xmit+0x894/0x1938
[  264.968100]  [<000003ff80bc3a5c>] sctp_packet_transmit+0x29d4/0x3648 [sctp]
[  264.968116]  [<000003ff80b7bf68>] sctp_outq_flush_ctrl.constprop.5+0x8d0/0xe50 [sctp]
[  264.968131]  [<000003ff80b7c716>] sctp_outq_flush+0x22e/0x7d8 [sctp]
[  264.968146]  [<000003ff80b35c68>] sctp_cmd_interpreter.isra.16+0x530/0x6800 [sctp]
[  264.968161]  [<000003ff80b3410a>] sctp_do_sm+0x222/0x648 [sctp]
[  264.968177]  [<000003ff80bbddac>] sctp_primitive_ASSOCIATE+0xbc/0xf8 [sctp]
[  264.968192]  [<000003ff80b93328>] __sctp_connect+0x830/0xc20 [sctp]
[  264.968208]  [<000003ff80bb11ce>] sctp_inet_connect+0x2e6/0x378 [sctp]
[  264.968212]  [<0000000001197942>] __sys_connect+0x21a/0x450
[  264.968215]  [<000000000119aff8>] sys_socketcall+0x3d0/0xb08
[  264.968218]  [<000000000184ea7a>] system_call+0x2a2/0x2c0

[...]

Just like ip_finish_output2() does for IPv4, check that we have enough
headroom in ip6_xmit(), and reallocate it if we don't.

This issue is older than git history.
Reported-by: default avatarJianlin Shi <jishi@redhat.com>
Signed-off-by: default avatarStefano Brivio <sbrivio@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fd018cb3
    • Jiri Wiesner's avatar
      ipv4: ipv6: netfilter: Adjust the frag mem limit when truesize changes · ffe5754d
      Jiri Wiesner authored 
      [ Upstream commit ebaf39e6 ]

The *_frag_reasm() functions are susceptible to miscalculating the byte
count of packet fragments in case the truesize of a head buffer changes.
The truesize member may be changed by the call to skb_unclone(), leaving
the fragment memory limit counter unbalanced even if all fragments are
processed. This miscalculation goes unnoticed as long as the network
namespace which holds the counter is not destroyed.

Should an attempt be made to destroy a network namespace that holds an
unbalanced fragment memory limit counter the cleanup of the namespace
never finishes. The thread handling the cleanup gets stuck in
inet_frags_exit_net() waiting for the percpu counter to reach zero. The
thread is usually in running state with a stacktrace similar to:

 PID: 1073   TASK: ffff880626711440  CPU: 1   COMMAND: "kworker/u48:4"
  #5 [ffff880621563d48] _raw_spin_lock at ffffffff815f5480
  #6 [ffff880621563d48] inet_evict_bucket at ffffffff8158020b
  #7 [ffff880621563d80] inet_frags_exit_net at ffffffff8158051c
  #8 [ffff880621563db0] ops_exit_list at ffffffff814f5856
  #9 [ffff880621563dd8] cleanup_net at ffffffff814f67c0
 #10 [ffff880621563e38] process_one_work at ffffffff81096f14

It is not possible to create new network namespaces, and processes
that call unshare() end up being stuck in uninterruptible sleep state
waiting to acquire the net_mutex.

The bug was observed in the IPv6 netfilter code by Per Sundstrom.
I thank him for his analysis of the problem. The parts of this patch
that apply to IPv4 and IPv6 fragment reassembly are preemptive measures.
Signed-off-by: default avatarJiri Wiesner <jwiesner@suse.com>
Reported-by: default avatarPer Sundstrom <per.sundstrom@redqube.se>
Acked-by: default avatarPeter Oskolkov <posk@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      ffe5754d
  3. 13 Dec, 2018 30 commits
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7