Commit Graph

1468 Commits

Author SHA1 Message Date
Sven Eckelmann
c5f261825f batman-adv: Hold rtnl lock during MTU update via netlink
commit 987aae75fc1041072941ffb622b45ce2359a99b9 upstream.

The automatic recalculation of the maximum allowed MTU is usually triggered
by code sections which are already rtnl lock protected by callers outside
of batman-adv. But when the fragmentation setting is changed via
batman-adv's own batadv genl family, then the rtnl lock is not yet taken.

But dev_set_mtu requires that the caller holds the rtnl lock because it
uses netdevice notifiers. And this code will then fail the check for this
lock:

  RTNL: assertion failed at net/core/dev.c (1953)

Cc: stable@vger.kernel.org
Reported-by: syzbot+f8812454d9b3ac00d282@syzkaller.appspotmail.com
Fixes: c6a953cce8d0 ("batman-adv: Trigger events for auto adjusted MTU")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230821-batadv-missing-mtu-rtnl-lock-v1-1-1c5a7bfe861e@narfation.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-30 16:27:25 +02:00
Remi Pommarel
61b71562be batman-adv: Fix batadv_v_ogm_aggr_send memory leak
commit 421d467dc2d483175bad4fb76a31b9e5a3d744cf upstream.

When batadv_v_ogm_aggr_send is called for an inactive interface, the skb
is silently dropped by batadv_v_ogm_send_to_if() but never freed causing
the following memory leak:

  unreferenced object 0xffff00000c164800 (size 512):
    comm "kworker/u8:1", pid 2648, jiffies 4295122303 (age 97.656s)
    hex dump (first 32 bytes):
      00 80 af 09 00 00 ff ff e1 09 00 00 75 01 60 83  ............u.`.
      1f 00 00 00 b8 00 00 00 15 00 05 00 da e3 d3 64  ...............d
    backtrace:
      [<0000000007ad20f6>] __kmalloc_track_caller+0x1a8/0x310
      [<00000000d1029e55>] kmalloc_reserve.constprop.0+0x70/0x13c
      [<000000008b9d4183>] __alloc_skb+0xec/0x1fc
      [<00000000c7af5051>] __netdev_alloc_skb+0x48/0x23c
      [<00000000642ee5f5>] batadv_v_ogm_aggr_send+0x50/0x36c
      [<0000000088660bd7>] batadv_v_ogm_aggr_work+0x24/0x40
      [<0000000042fc2606>] process_one_work+0x3b0/0x610
      [<000000002f2a0b1c>] worker_thread+0xa0/0x690
      [<0000000059fae5d4>] kthread+0x1fc/0x210
      [<000000000c587d3a>] ret_from_fork+0x10/0x20

Free the skb in that case to fix this leak.

Cc: stable@vger.kernel.org
Fixes: 0da0035942 ("batman-adv: OGMv2 - add basic infrastructure")
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-30 16:27:25 +02:00
Remi Pommarel
5fb1a21337 batman-adv: Fix TT global entry leak when client roamed back
commit d25ddb7e788d34cf27ff1738d11a87cb4b67d446 upstream.

When a client roamed back to a node before it got time to destroy the
pending local entry (i.e. within the same originator interval) the old
global one is directly removed from hash table and left as such.

But because this entry had an extra reference taken at lookup (i.e using
batadv_tt_global_hash_find) there is no way its memory will be reclaimed
at any time causing the following memory leak:

  unreferenced object 0xffff0000073c8000 (size 18560):
    comm "softirq", pid 0, jiffies 4294907738 (age 228.644s)
    hex dump (first 32 bytes):
      06 31 ac 12 c7 7a 05 00 01 00 00 00 00 00 00 00  .1...z..........
      2c ad be 08 00 80 ff ff 6c b6 be 08 00 80 ff ff  ,.......l.......
    backtrace:
      [<00000000ee6e0ffa>] kmem_cache_alloc+0x1b4/0x300
      [<000000000ff2fdbc>] batadv_tt_global_add+0x700/0xe20
      [<00000000443897c7>] _batadv_tt_update_changes+0x21c/0x790
      [<000000005dd90463>] batadv_tt_update_changes+0x3c/0x110
      [<00000000a2d7fc57>] batadv_tt_tvlv_unicast_handler_v1+0xafc/0xe10
      [<0000000011793f2a>] batadv_tvlv_containers_process+0x168/0x2b0
      [<00000000b7cbe2ef>] batadv_recv_unicast_tvlv+0xec/0x1f4
      [<0000000042aef1d8>] batadv_batman_skb_recv+0x25c/0x3a0
      [<00000000bbd8b0a2>] __netif_receive_skb_core.isra.0+0x7a8/0xe90
      [<000000004033d428>] __netif_receive_skb_one_core+0x64/0x74
      [<000000000f39a009>] __netif_receive_skb+0x48/0xe0
      [<00000000f2cd8888>] process_backlog+0x174/0x344
      [<00000000507d6564>] __napi_poll+0x58/0x1f4
      [<00000000b64ef9eb>] net_rx_action+0x504/0x590
      [<00000000056fa5e4>] _stext+0x1b8/0x418
      [<00000000878879d6>] run_ksoftirqd+0x74/0xa4
  unreferenced object 0xffff00000bae1a80 (size 56):
    comm "softirq", pid 0, jiffies 4294910888 (age 216.092s)
    hex dump (first 32 bytes):
      00 78 b1 0b 00 00 ff ff 0d 50 00 00 00 00 00 00  .x.......P......
      00 00 00 00 00 00 00 00 50 c8 3c 07 00 00 ff ff  ........P.<.....
    backtrace:
      [<00000000ee6e0ffa>] kmem_cache_alloc+0x1b4/0x300
      [<00000000d9aaa49e>] batadv_tt_global_add+0x53c/0xe20
      [<00000000443897c7>] _batadv_tt_update_changes+0x21c/0x790
      [<000000005dd90463>] batadv_tt_update_changes+0x3c/0x110
      [<00000000a2d7fc57>] batadv_tt_tvlv_unicast_handler_v1+0xafc/0xe10
      [<0000000011793f2a>] batadv_tvlv_containers_process+0x168/0x2b0
      [<00000000b7cbe2ef>] batadv_recv_unicast_tvlv+0xec/0x1f4
      [<0000000042aef1d8>] batadv_batman_skb_recv+0x25c/0x3a0
      [<00000000bbd8b0a2>] __netif_receive_skb_core.isra.0+0x7a8/0xe90
      [<000000004033d428>] __netif_receive_skb_one_core+0x64/0x74
      [<000000000f39a009>] __netif_receive_skb+0x48/0xe0
      [<00000000f2cd8888>] process_backlog+0x174/0x344
      [<00000000507d6564>] __napi_poll+0x58/0x1f4
      [<00000000b64ef9eb>] net_rx_action+0x504/0x590
      [<00000000056fa5e4>] _stext+0x1b8/0x418
      [<00000000878879d6>] run_ksoftirqd+0x74/0xa4

Releasing the extra reference from batadv_tt_global_hash_find even at
roam back when batadv_tt_global_free is called fixes this memory leak.

Cc: stable@vger.kernel.org
Fixes: 068ee6e204 ("batman-adv: roaming handling mechanism redesign")
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Signed-off-by; Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-30 16:27:25 +02:00
Remi Pommarel
e6e9d78081 batman-adv: Do not get eth header before batadv_check_management_packet
commit eac27a41ab641de074655d2932fc7f8cdb446881 upstream.

If received skb in batadv_v_elp_packet_recv or batadv_v_ogm_packet_recv
is either cloned or non linearized then its data buffer will be
reallocated by batadv_check_management_packet when skb_cow or
skb_linearize get called. Thus geting ethernet header address inside
skb data buffer before batadv_check_management_packet had any chance to
reallocate it could lead to the following kernel panic:

  Unable to handle kernel paging request at virtual address ffffff8020ab069a
  Mem abort info:
    ESR = 0x96000007
    EC = 0x25: DABT (current EL), IL = 32 bits
    SET = 0, FnV = 0
    EA = 0, S1PTW = 0
    FSC = 0x07: level 3 translation fault
  Data abort info:
    ISV = 0, ISS = 0x00000007
    CM = 0, WnR = 0
  swapper pgtable: 4k pages, 39-bit VAs, pgdp=0000000040f45000
  [ffffff8020ab069a] pgd=180000007fffa003, p4d=180000007fffa003, pud=180000007fffa003, pmd=180000007fefe003, pte=0068000020ab0706
  Internal error: Oops: 96000007 [#1] SMP
  Modules linked in: ahci_mvebu libahci_platform libahci dvb_usb_af9035 dvb_usb_dib0700 dib0070 dib7000m dibx000_common ath11k_pci ath10k_pci ath10k_core mwl8k_new nf_nat_sip nf_conntrack_sip xhci_plat_hcd xhci_hcd nf_nat_pptp nf_conntrack_pptp at24 sbsa_gwdt
  CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.15.42-00066-g3242268d425c-dirty #550
  Hardware name: A8k (DT)
  pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : batadv_is_my_mac+0x60/0xc0
  lr : batadv_v_ogm_packet_recv+0x98/0x5d0
  sp : ffffff8000183820
  x29: ffffff8000183820 x28: 0000000000000001 x27: ffffff8014f9af00
  x26: 0000000000000000 x25: 0000000000000543 x24: 0000000000000003
  x23: ffffff8020ab0580 x22: 0000000000000110 x21: ffffff80168ae880
  x20: 0000000000000000 x19: ffffff800b561000 x18: 0000000000000000
  x17: 0000000000000000 x16: 0000000000000000 x15: 00dc098924ae0032
  x14: 0f0405433e0054b0 x13: ffffffff00000080 x12: 0000004000000001
  x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
  x8 : 0000000000000000 x7 : ffffffc076dae000 x6 : ffffff8000183700
  x5 : ffffffc00955e698 x4 : ffffff80168ae000 x3 : ffffff80059cf000
  x2 : ffffff800b561000 x1 : ffffff8020ab0696 x0 : ffffff80168ae880
  Call trace:
   batadv_is_my_mac+0x60/0xc0
   batadv_v_ogm_packet_recv+0x98/0x5d0
   batadv_batman_skb_recv+0x1b8/0x244
   __netif_receive_skb_core.isra.0+0x440/0xc74
   __netif_receive_skb_one_core+0x14/0x20
   netif_receive_skb+0x68/0x140
   br_pass_frame_up+0x70/0x80
   br_handle_frame_finish+0x108/0x284
   br_handle_frame+0x190/0x250
   __netif_receive_skb_core.isra.0+0x240/0xc74
   __netif_receive_skb_list_core+0x6c/0x90
   netif_receive_skb_list_internal+0x1f4/0x310
   napi_complete_done+0x64/0x1d0
   gro_cell_poll+0x7c/0xa0
   __napi_poll+0x34/0x174
   net_rx_action+0xf8/0x2a0
   _stext+0x12c/0x2ac
   run_ksoftirqd+0x4c/0x7c
   smpboot_thread_fn+0x120/0x210
   kthread+0x140/0x150
   ret_from_fork+0x10/0x20
  Code: f9403844 eb03009f 54fffee1 f94

Thus ethernet header address should only be fetched after
batadv_check_management_packet has been called.

Fixes: 0da0035942 ("batman-adv: OGMv2 - add basic infrastructure")
Cc: stable@vger.kernel.org
Signed-off-by: Remi Pommarel <repk@triplefau.lt>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-30 16:27:25 +02:00
Sven Eckelmann
c97442e098 batman-adv: Don't increase MTU when set by user
commit d8e42a2b0addf238be8b3b37dcd9795a5c1be459 upstream.

If the user set an MTU value, it usually means that there are special
requirements for the MTU. But if an interface gots activated, the MTU was
always recalculated and then the user set value was overwritten.

The only reason why this user set value has to be overwritten, is when the
MTU has to be decreased because batman-adv is not able to transfer packets
with the user specified size.

Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Cc: stable@vger.kernel.org
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-30 16:27:25 +02:00
Sven Eckelmann
22288ea6be batman-adv: Trigger events for auto adjusted MTU
commit c6a953cce8d0438391e6da48c8d0793d3fbfcfa6 upstream.

If an interface changes the MTU, it is expected that an NETDEV_PRECHANGEMTU
and NETDEV_CHANGEMTU notification events is triggered. This worked fine for
.ndo_change_mtu based changes because core networking code took care of it.
But for auto-adjustments after hard-interfaces changes, these events were
simply missing.

Due to this problem, non-batman-adv components weren't aware of MTU changes
and thus couldn't perform their own tasks correctly.

Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Cc: stable@vger.kernel.org
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-30 16:27:25 +02:00
Vladislav Efanov
a3a99a069e batman-adv: Broken sync while rescheduling delayed work
commit abac3ac97fe8734b620e7322a116450d7f90aa43 upstream.

Syzkaller got a lot of crashes like:
KASAN: use-after-free Write in *_timers*

All of these crashes point to the same memory area:

The buggy address belongs to the object at ffff88801f870000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 5320 bytes inside of
 8192-byte region [ffff88801f870000, ffff88801f872000)

This area belongs to :
        batadv_priv->batadv_priv_dat->delayed_work->timer_list

The reason for these issues is the lack of synchronization. Delayed
work (batadv_dat_purge) schedules new timer/work while the device
is being deleted. As the result new timer/delayed work is set after
cancel_delayed_work_sync() was called. So after the device is freed
the timer list contains pointer to already freed memory.

Found by Linux Verification Center (linuxtesting.org) with syzkaller.

Cc: stable@kernel.org
Fixes: 2f1dfbe185 ("batman-adv: Distributed ARP Table - implement local storage")
Signed-off-by: Vladislav Efanov <VEfanov@ispras.ru>
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14 10:59:56 +02:00
Sven Eckelmann
3915341a93 batman-adv: Don't skb_split skbuffs with frag_list
[ Upstream commit a063f2fba3fa633a599253b62561051ac185fa99 ]

The receiving interface might have used GRO to receive more fragments than
MAX_SKB_FRAGS fragments. In this case, these will not be stored in
skb_shinfo(skb)->frags but merged into the frag list.

batman-adv relies on the function skb_split to split packets up into
multiple smaller packets which are not larger than the MTU on the outgoing
interface. But this function cannot handle frag_list entries and is only
operating on skb_shinfo(skb)->frags. If it is still trying to split such an
skb and xmit'ing it on an interface without support for NETIF_F_FRAGLIST,
then validate_xmit_skb() will try to linearize it. But this fails due to
inconsistent information. And __pskb_pull_tail will trigger a BUG_ON after
skb_copy_bits() returns an error.

In case of entries in frag_list, just linearize the skb before operating on
it with skb_split().

Reported-by: Felix Kaechele <felix@kaechele.ca>
Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Tested-by: Felix Kaechele <felix@kaechele.ca>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-05-18 09:47:24 +02:00
Eric Dumazet
fbb7b03320 ipv6: make mc_forwarding atomic
[ Upstream commit 145c7a793838add5e004e7d49a67654dc7eba147 ]

This fixes minor data-races in ip6_mc_input() and
batadv_mcast_mla_rtr_flags_softif_get_ipv6()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-15 14:18:32 +02:00
Sven Eckelmann
ed05368024 batman-adv: Don't expect inter-netns unique iflink indices
commit 6c1f41afc1dbe59d9d3c8bb0d80b749c119aa334 upstream.

The ifindex doesn't have to be unique for multiple network namespaces on
the same machine.

  $ ip netns add test1
  $ ip -net test1 link add dummy1 type dummy
  $ ip netns add test2
  $ ip -net test2 link add dummy2 type dummy

  $ ip -net test1 link show dev dummy1
  6: dummy1: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 96:81:55:1e:dd:85 brd ff:ff:ff:ff:ff:ff
  $ ip -net test2 link show dev dummy2
  6: dummy2: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
      link/ether 5a:3c:af:35:07:c3 brd ff:ff:ff:ff:ff:ff

But the batman-adv code to walk through the various layers of virtual
interfaces uses this assumption because dev_get_iflink handles it
internally and doesn't return the actual netns of the iflink. And
dev_get_iflink only documents the situation where ifindex == iflink for
physical devices.

But only checking for dev->netdev_ops->ndo_get_iflink is also not an option
because ipoib_get_iflink implements it even when it sometimes returns an
iflink != ifindex and sometimes iflink == ifindex. The caller must
therefore make sure itself to check both netns and iflink + ifindex for
equality. Only when they are equal, a "physical" interface was detected
which should stop the traversal. On the other hand, vxcan_get_iflink can
also return 0 in case there was currently no valid peer. In this case, it
is still necessary to stop.

Fixes: b7eddd0b39 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Fixes: 5ed4a460a1 ("batman-adv: additional checks for virtual interfaces on top of WiFi")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:07:47 +01:00
Sven Eckelmann
8639532271 batman-adv: Request iflink once in batadv_get_real_netdevice
commit 6116ba09423f7d140f0460be6a1644dceaad00da upstream.

There is no need to call dev_get_iflink multiple times for the same
net_device in batadv_get_real_netdevice. And since some of the
ndo_get_iflink callbacks are dynamic (for example via RCUs like in
vxcan_get_iflink), it could easily happen that the returned values are not
stable. The pre-checks before __dev_get_by_index are then of course bogus.

Fixes: 5ed4a460a1 ("batman-adv: additional checks for virtual interfaces on top of WiFi")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:07:47 +01:00
Sven Eckelmann
a1ccea6183 batman-adv: Request iflink once in batadv-on-batadv check
commit 690bb6fb64f5dc7437317153902573ecad67593d upstream.

There is no need to call dev_get_iflink multiple times for the same
net_device in batadv_is_on_batman_iface. And since some of the
.ndo_get_iflink callbacks are dynamic (for example via RCUs like in
vxcan_get_iflink), it could easily happen that the returned values are not
stable. The pre-checks before __dev_get_by_index are then of course bogus.

Fixes: b7eddd0b39 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-08 19:07:47 +01:00
Linus Lüssing
c7e4004b38 batman-adv: allow netlink usage in unprivileged containers
[ Upstream commit 9057d6c23e7388ee9d037fccc9a7bc8557ce277b ]

Currently, creating a batman-adv interface in an unprivileged LXD
container and attaching secondary interfaces to it with "ip" or "batctl"
works fine. However all batctl debug and configuration commands
fail:

  root@container:~# batctl originators
  Error received: Operation not permitted
  root@container:~# batctl orig_interval
  1000
  root@container:~# batctl orig_interval 2000
  root@container:~# batctl orig_interval
  1000

To fix this change the generic netlink permissions from GENL_ADMIN_PERM
to GENL_UNS_ADMIN_PERM. This way a batman-adv interface is fully
maintainable as root from within a user namespace, from an unprivileged
container.

All except one batman-adv netlink setting are per interface and do not
leak information or change settings from the host system and are
therefore save to retrieve or modify as root from within an unprivileged
container.

"batctl routing_algo" / BATADV_CMD_GET_ROUTING_ALGOS is the only
exception: It provides the batman-adv kernel module wide default routing
algorithm. However it is read-only from netlink and an unprivileged
container is still not allowed to modify
/sys/module/batman_adv/parameters/routing_algo. Instead it is advised to
use the newly introduced "batctl if create routing_algo RA_NAME" /
IFLA_BATADV_ALGO_NAME to set the routing algorithm on interface
creation, which already works fine in an unprivileged container.

Cc: Tycho Andersen <tycho@tycho.pizza>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-01-27 09:19:41 +01:00
Linus Lüssing
bcbfc77800 batman-adv: mcast: don't send link-local multicast to mcast routers
commit 938f2e0b57ffe8a6df71e1e177b2978b1b33fe5e upstream.

The addition of routable multicast TX handling introduced a
bug/regression for packets with a link-local multicast destination:
These packets would be sent to all batman-adv nodes with a multicast
router and to all batman-adv nodes with an old version without multicast
router detection.

This even disregards the batman-adv multicast fanout setting, which can
potentially lead to an unwanted, high number of unicast transmissions or
even congestion.

Fixing this by avoiding to send link-local multicast packets to nodes in
the multicast router list.

Fixes: 11d458c1cb ("batman-adv: mcast: apply optimizations for routable packets, too")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-01-11 15:23:32 +01:00
Sven Eckelmann
56a32c8276 batman-adv: Don't always reallocate the fragmentation skb head
commit 992b03b88e36254e26e9a4977ab948683e21bd9f upstream.

When a packet is fragmented by batman-adv, the original batman-adv header
is not modified. Only a new fragmentation is inserted between the original
one and the ethernet header. The code must therefore make sure that it has
a writable region of this size in the skbuff head.

But it is not useful to always reallocate the skbuff by this size even when
there would be more than enough headroom still in the skb. The reallocation
is just to costly during in this codepath.

Fixes: ee75ed8887 ("batman-adv: Fragment and send skbs larger than mtu")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26 10:47:22 +01:00
Sven Eckelmann
08bceb1e30 batman-adv: Reserve needed_*room for fragments
commit c5cbfc87558168ef4c3c27ce36eba6b83391db19 upstream.

The batadv net_device is trying to propagate the needed_headroom and
needed_tailroom from the lower devices. This is needed to avoid cost
intensive reallocations using pskb_expand_head during the transmission.

But the fragmentation code split the skb's without adding extra room at the
end/beginning of the various fragments. This reduced the performance of
transmissions over complex scenarios (batadv on vxlan on wireguard) because
the lower devices had to perform the reallocations at least once.

Fixes: ee75ed8887 ("batman-adv: Fragment and send skbs larger than mtu")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26 10:47:22 +01:00
Sven Eckelmann
374c55d416 batman-adv: Consider fragmentation for needed_headroom
commit 4ca23e2c2074465bff55ea14221175fecdf63c5f upstream.

If a batman-adv packets has to be fragmented, then the original batman-adv
packet header is not stripped away. Instead, only a new header is added in
front of the packet after it was split.

This size must be considered to avoid cost intensive reallocations during
the transmission through the various device layers.

Fixes: 7bca68c784 ("batman-adv: Add lower layer needed_(head|tail)room to own ones")
Reported-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-26 10:47:22 +01:00
Pavel Skripkin
6422e84718 net: batman-adv: fix error handling
commit 6f68cd634856f8ca93bafd623ba5357e0f648c68 upstream.

Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was
in wrong error handling in batadv_mesh_init().

Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case
of any batadv_*_init() calls failure. This approach may work well, when
there is some kind of indicator, which can tell which parts of batadv are
initialized; but there isn't any.

All written above lead to cleaning up uninitialized fields. Even if we hide
ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit
GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1]

To fix these bugs we can unwind batadv_*_init() calls one by one.
It is good approach for 2 reasons: 1) It fixes bugs on error handling
path 2) It improves the performance, since we won't call unneeded
batadv_*_free() functions.

So, this patch makes all batadv_*_init() clean up all allocated memory
before returning with an error to no call correspoing batadv_*_free()
and open-codes batadv_mesh_free() with proper order to avoid touching
uninitialized fields.

Link: https://lore.kernel.org/netdev/000000000000c87fbd05cef6bcb0@google.com/ [1]
Reported-and-tested-by: syzbot+28b0702ada0bf7381f58@syzkaller.appspotmail.com
Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-11-02 19:46:14 +01:00
Sven Eckelmann
e7fbd8184f batman-adv: Avoid WARN_ON timing related checks
[ Upstream commit 9f460ae31c4435fd022c443a6029352217a16ac1 ]

The soft/batadv interface for a queued OGM can be changed during the time
the OGM was queued for transmission and when the OGM is actually
transmitted by the worker.

But WARN_ON must be used to denote kernel bugs and not to print simple
warnings. A warning can simply be printed using pr_warn.

Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzbot+c0b807de416427ff3dd1@syzkaller.appspotmail.com
Fixes: ef0a937f7a ("batman-adv: consider outgoing interface in OGM sending")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-06-23 14:41:23 +02:00
Tetsuo Handa
9de1caa110 batman-adv: initialize "struct batadv_tvlv_tt_vlan_data"->reserved field
commit 08c27f3322fec11950b8f1384aa0f3b11d028528 upstream.

KMSAN found uninitialized value at batadv_tt_prepare_tvlv_local_data()
[1], for commit ced72933a5 ("batman-adv: use CRC32C instead of CRC16
in TT code") inserted 'reserved' field into "struct batadv_tvlv_tt_data"
and commit 7ea7b4a142 ("batman-adv: make the TT CRC logic VLAN
specific") moved that field to "struct batadv_tvlv_tt_vlan_data" but left
that field uninitialized.

[1] https://syzkaller.appspot.com/bug?id=07f3e6dba96f0eb3cabab986adcd8a58b9bdbe9d

Reported-by: syzbot <syzbot+50ee810676e6a089487b@syzkaller.appspotmail.com>
Tested-by: syzbot <syzbot+50ee810676e6a089487b@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: ced72933a5 ("batman-adv: use CRC32C instead of CRC16 in TT code")
Fixes: 7ea7b4a142 ("batman-adv: make the TT CRC logic VLAN specific")
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-14 08:24:11 +02:00
Taehee Yoo
95b1f32631 batman-adv: set .owner to THIS_MODULE
[ Upstream commit 14a2e551faea53d45bc11629a9dac88f88950ca7 ]

If THIS_MODULE is not set, the module would be removed while debugfs is
being used.
It eventually makes kernel panic.

Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-12-02 08:49:50 +01:00
Linus Lüssing
d9fadccbf2 batman-adv: mcast: fix duplicate mcast packets from BLA backbone to mesh
[ Upstream commit 2369e827046920ef0599e6a36b975ac5c0a359c2 ]

Scenario:
* Multicast frame send from BLA backbone gateways (multiple nodes
  with their bat0 bridged together, with BLA enabled) sharing the same
  LAN to nodes in the mesh

Issue:
* Nodes receive the frame multiple times on bat0 from the mesh,
  once from each foreign BLA backbone gateway which shares the same LAN
  with another

For multicast frames via batman-adv broadcast packets coming from the
same BLA backbone but from different backbone gateways duplicates are
currently detected via a CRC history of previously received packets.

However this CRC so far was not performed for multicast frames received
via batman-adv unicast packets. Fixing this by appyling the same check
for such packets, too.

Room for improvements in the future: Ideally we would introduce the
possibility to not only claim a client, but a complete originator, too.
This would allow us to only send a multicast-in-unicast packet from a BLA
backbone gateway claiming the node and by that avoid potential redundant
transmissions in the first place.

Fixes: 279e89b2281a ("batman-adv: add broadcast duplicate check")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:18:19 +02:00
Linus Lüssing
5d87744928 batman-adv: mcast: fix duplicate mcast packets in BLA backbone from mesh
[ Upstream commit 74c09b7275126da1b642b90c9cdc3ae8b729ad4b ]

Scenario:
* Multicast frame send from mesh to a BLA backbone (multiple nodes
  with their bat0 bridged together, with BLA enabled)

Issue:
* BLA backbone nodes receive the frame multiple times on bat0,
  once from mesh->bat0 and once from each backbone_gw from LAN

For unicast, a node will send only to the best backbone gateway
according to the TQ. However for multicast we currently cannot determine
if multiple destination nodes share the same backbone if they don't share
the same backbone with us. So we need to keep sending the unicasts to
all backbone gateways and let the backbone gateways decide which one
will forward the frame. We can use the CLAIM mechanism to make this
decision.

One catch: The batman-adv gateway feature for DHCP packets potentially
sends multicast packets in the same batman-adv unicast header as the
multicast optimizations code. And we are not allowed to drop those even
if we did not claim the source address of the sender, as for such
packets there is only this one multicast-in-unicast packet.

How can we distinguish the two cases?

The gateway feature uses a batman-adv unicast 4 address header. While
the multicast-to-unicasts feature uses a simple, 3 address batman-adv
unicast header. So let's use this to distinguish.

Fixes: fe2da6ff27 ("batman-adv: check incoming packet type for bla")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:18:19 +02:00
Linus Lüssing
24e5e941d8 batman-adv: mcast: fix duplicate mcast packets in BLA backbone from LAN
[ Upstream commit 3236d215ad38a3f5372e65cd1e0a52cf93d3c6a2 ]

Scenario:
* Multicast frame send from a BLA backbone (multiple nodes with
  their bat0 bridged together, with BLA enabled)

Issue:
* BLA backbone nodes receive the frame multiple times on bat0

For multicast frames received via batman-adv broadcast packets the
originator of the broadcast packet is checked before decapsulating and
forwarding the frame to bat0 (batadv_bla_is_backbone_gw()->
batadv_recv_bcast_packet()). If it came from a node which shares the
same BLA backbone with us then it is not forwarded to bat0 to avoid a
loop.

When sending a multicast frame in a non-4-address batman-adv unicast
packet we are currently missing this check - and cannot do so because
the batman-adv unicast packet has no originator address field.

However, we can simply fix this on the sender side by only sending the
multicast frame via unicasts to interested nodes which do not share the
same BLA backbone with us. This also nicely avoids some unnecessary
transmissions on mesh side.

Note that no infinite loop was observed, probably because of dropping
via batadv_interface_tx()->batadv_bla_tx(). However the duplicates still
utterly confuse switches/bridges, ICMPv6 duplicate address detection and
neighbor discovery and therefore leads to long delays before being able
to establish TCP connections, for instance. And it also leads to the Linux
bridge printing messages like:
"br-lan: received packet on eth1 with own address as source address ..."

Fixes: 2d3f6ccc4e ("batman-adv: Modified forwarding behaviour for multicast packets")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:18:19 +02:00
Sven Eckelmann
8c6ba1878a batman-adv: Add missing include for in_interrupt()
[ Upstream commit 4bba9dab86b6ac15ca560ef1f2b5aa4529cbf784 ]

The fix for receiving (internally generated) bla packets outside the
interrupt context introduced the usage of in_interrupt(). But this
functionality is only defined in linux/preempt.h which was not included
with the same patch.

Fixes: 279e89b2281a ("batman-adv: bla: use netif_rx_ni when not in interrupt context")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:18:19 +02:00
Linus Lüssing
b6112ff05f batman-adv: mcast/TT: fix wrongly dropped or rerouted packets
[ Upstream commit 7dda5b3384121181c4e79f6eaeac2b94c0622c8d ]

The unicast packet rerouting code makes several assumptions. For
instance it assumes that there is always exactly one destination in the
TT. This breaks for multicast frames in a unicast packets in several ways:

For one thing if there is actually no TT entry and the destination node
was selected due to the multicast tvlv flags it announced. Then an
intermediate node will wrongly drop the packet.

For another thing if there is a TT entry but the TTVN of this entry is
newer than the originally addressed destination node: Then the
intermediate node will wrongly redirect the packet, leading to
duplicated multicast packets at a multicast listener and missing
packets at other multicast listeners or multicast routers.

Fixing this by not applying the unicast packet rerouting to batman-adv
unicast packets with a multicast payload. We are not able to detect a
roaming multicast listener at the moment and will just continue to send
the multicast frame to both the new and old destination for a while in
case of such a roaming multicast listener.

Fixes: a73105b8d4 ("batman-adv: improved client announcement mechanism")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:18:17 +02:00
Linus Lüssing
e0117ad11b batman-adv: bla: fix type misuse for backbone_gw hash indexing
[ Upstream commit 097930e85f90f252c44dc0d084598265dd44ca48 ]

It seems that due to a copy & paste error the void pointer
in batadv_choose_backbone_gw() is cast to the wrong type.

Fixing this by using "struct batadv_bla_backbone_gw" instead of "struct
batadv_bla_claim" which better matches the caller's side.

For now it seems that we were lucky because the two structs both have
their orig/vid and addr/vid in the beginning. However I stumbled over
this issue when I was trying to add some debug variables in front of
"orig" in batadv_backbone_gw, which caused hash lookups to fail.

Fixes: 07568d0369 ("batman-adv: don't rely on positions in struct for hashing")
Signed-off-by: Linus Lüssing <ll@simonwunderlich.de>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-10-01 13:18:16 +02:00
Jussi Kivilinna
2f2786bb9d batman-adv: bla: use netif_rx_ni when not in interrupt context
[ Upstream commit 279e89b2281af3b1a9f04906e157992c19c9f163 ]

batadv_bla_send_claim() gets called from worker thread context through
batadv_bla_periodic_work(), thus netif_rx_ni needs to be used in that
case. This fixes "NOHZ: local_softirq_pending 08" log messages seen
when batman-adv is enabled.

Fixes: 23721387c4 ("batman-adv: add basic bridge loop avoidance code")
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@haltian.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-09 19:12:23 +02:00
Linus Lüssing
fd8b3ef644 batman-adv: Fix own OGM check in aggregated OGMs
[ Upstream commit d8bf0c01642275c7dca1e5d02c34e4199c200b1f ]

The own OGM check is currently misplaced and can lead to the following
issues:

For one thing we might receive an aggregated OGM from a neighbor node
which has our own OGM in the first place. We would then not only skip
our own OGM but erroneously also any other, following OGM in the
aggregate.

For another, we might receive an OGM aggregate which has our own OGM in
a place other then the first one. Then we would wrongly not skip this
OGM, leading to populating the orginator and gateway table with ourself.

Fixes: 9323158ef9 ("batman-adv: OGMv2 - implement originators logic")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-09 19:12:23 +02:00
Sven Eckelmann
2344f2f186 batman-adv: Avoid uninitialized chaddr when handling DHCP
[ Upstream commit 303216e76dcab6049c9d42390b1032f0649a8206 ]

The gateway client code can try to optimize the delivery of DHCP packets to
avoid broadcasting them through the whole mesh. But also transmissions to
the client can be optimized by looking up the destination via the chaddr of
the DHCP packet.

But the chaddr is currently only done when chaddr is fully inside the
non-paged area of the skbuff. Otherwise it will not be initialized and the
unoptimized path should have been taken.

But the implementation didn't handle this correctly. It didn't retrieve the
correct chaddr but still tried to perform the TT lookup with this
uninitialized memory.

Reported-by: syzbot+ab16e463b903f5a37036@syzkaller.appspotmail.com
Fixes: 6c413b1c22 ("batman-adv: send every DHCP packet as bat-unicast")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-09-09 19:12:23 +02:00
Sven Eckelmann
f503e7fe30 batman-adv: Revert "disable ethtool link speed detection when auto negotiation off"
[ Upstream commit 9ad346c90509ebd983f60da7d082f261ad329507 ]

The commit 8c46fcd783 ("batman-adv: disable ethtool link speed detection
when auto negotiation off") disabled the usage of ethtool's link_ksetting
when auto negotation was enabled due to invalid values when used with
tun/tap virtual net_devices. According to the patch, automatic measurements
should be used for these kind of interfaces.

But there are major flaws with this argumentation:

* automatic measurements are not implemented
* auto negotiation has nothing to do with the validity of the retrieved
  values

The first point has to be fixed by a longer patch series. The "validity"
part of the second point must be addressed in the same patch series by
dropping the usage of ethtool's link_ksetting (thus always doing automatic
measurements over ethernet).

Drop the patch again to have more default values for various net_device
types/configurations. The user can still overwrite them using the
batadv_hardif's BATADV_ATTR_THROUGHPUT_OVERRIDE.

Reported-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-22 09:30:56 +02:00
Xiyu Yang
d8eb5a1cde batman-adv: Fix refcnt leak in batadv_v_ogm_process
commit 6f91a3f7af4186099dd10fa530dd7e0d9c29747d upstream.

batadv_v_ogm_process() invokes batadv_hardif_neigh_get(), which returns
a reference of the neighbor object to "hardif_neigh" with increased
refcount.

When batadv_v_ogm_process() returns, "hardif_neigh" becomes invalid, so
the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling paths of
batadv_v_ogm_process(). When batadv_v_ogm_orig_get() fails to get the
orig node and returns NULL, the refcnt increased by
batadv_hardif_neigh_get() is not decreased, causing a refcnt leak.

Fix this issue by jumping to "out" label when batadv_v_ogm_orig_get()
fails to get the orig node.

Fixes: 9323158ef9 ("batman-adv: OGMv2 - implement originators logic")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-14 07:58:28 +02:00
Xiyu Yang
13f968c8b7 batman-adv: Fix refcnt leak in batadv_store_throughput_override
commit 6107c5da0fca8b50b4d3215e94d619d38cc4a18c upstream.

batadv_show_throughput_override() invokes batadv_hardif_get_by_netdev(),
which gets a batadv_hard_iface object from net_dev with increased refcnt
and its reference is assigned to a local pointer 'hard_iface'.

When batadv_store_throughput_override() returns, "hard_iface" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The issue happens in one error path of
batadv_store_throughput_override(). When batadv_parse_throughput()
returns NULL, the refcnt increased by batadv_hardif_get_by_netdev() is
not decreased, causing a refcnt leak.

Fix this issue by jumping to "out" label when batadv_parse_throughput()
returns NULL.

Fixes: 0b5ecc6811 ("batman-adv: add throughput override attribute to hard_ifaces")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-14 07:58:28 +02:00
Xiyu Yang
b713481058 batman-adv: Fix refcnt leak in batadv_show_throughput_override
commit f872de8185acf1b48b954ba5bd8f9bc0a0d14016 upstream.

batadv_show_throughput_override() invokes batadv_hardif_get_by_netdev(),
which gets a batadv_hard_iface object from net_dev with increased refcnt
and its reference is assigned to a local pointer 'hard_iface'.

When batadv_show_throughput_override() returns, "hard_iface" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The issue happens in the normal path of
batadv_show_throughput_override(), which forgets to decrease the refcnt
increased by batadv_hardif_get_by_netdev() before the function returns,
causing a refcnt leak.

Fix this issue by calling batadv_hardif_put() before the
batadv_show_throughput_override() returns in the normal path.

Fixes: 0b5ecc6811 ("batman-adv: add throughput override attribute to hard_ifaces")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-14 07:58:27 +02:00
George Spelvin
bee7e9da58 batman-adv: fix batadv_nc_random_weight_tq
commit fd0c42c4dea54335967c5a86f15fc064235a2797 upstream.

and change to pseudorandom numbers, as this is a traffic dithering
operation that doesn't need crypto-grade.

The previous code operated in 4 steps:

1. Generate a random byte 0 <= rand_tq <= 255
2. Multiply it by BATADV_TQ_MAX_VALUE - tq
3. Divide by 255 (= BATADV_TQ_MAX_VALUE)
4. Return BATADV_TQ_MAX_VALUE - rand_tq

This would apperar to scale (BATADV_TQ_MAX_VALUE - tq) by a random
value between 0/255 and 255/255.

But!  The intermediate value between steps 3 and 4 is stored in a u8
variable.  So it's truncated, and most of the time, is less than 255, after
which the division produces 0.  Specifically, if tq is odd, the product is
always even, and can never be 255.  If tq is even, there's exactly one
random byte value that will produce a product byte of 255.

Thus, the return value is 255 (511/512 of the time) or 254 (1/512
of the time).

If we assume that the truncation is a bug, and the code is meant to scale
the input, a simpler way of looking at it is that it's returning a random
value between tq and BATADV_TQ_MAX_VALUE, inclusive.

Well, we have an optimized function for doing just that.

Fixes: 3c12de9a5c ("batman-adv: network coding - code and transmit packets if possible")
Signed-off-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-05-14 07:58:27 +02:00
Sven Eckelmann
130bd50d00 batman-adv: Don't schedule OGM for disabled interface
commit 8e8ce08198de193e3d21d42e96945216e3d9ac7f upstream.

A transmission scheduling for an interface which is currently dropped by
batadv_iv_ogm_iface_disable could still be in progress. The B.A.T.M.A.N. V
is simply cancelling the workqueue item in an synchronous way but this is
not possible with B.A.T.M.A.N. IV because the OGM submissions are
intertwined.

Instead it has to stop submitting the OGM when it detect that the buffer
pointer is set to NULL.

Reported-by: syzbot+a98f2016f40b9cd3818a@syzkaller.appspotmail.com
Reported-by: syzbot+ac36b6a33c28a491e929@syzkaller.appspotmail.com
Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-18 07:17:54 +01:00
Sven Eckelmann
7c69f6a227 batman-adv: Fix DAT candidate selection on little endian systems
commit 4cc4a1708903f404d2ca0dfde30e71e052c6cbc9 upstream.

The distributed arp table is using a DHT to store and retrieve MAC address
information for an IP address. This is done using unicast messages to
selected peers. The potential peers are looked up using the IP address and
the VID.

While the IP address is always stored in big endian byte order, this is not
the case of the VID. It can (depending on the host system) either be big
endian or little endian. The host must therefore always convert it to big
endian to ensure that all devices calculate the same peers for the same
lookup data.

Fixes: be1db4f661 ("batman-adv: make the Distributed ARP Table vlan aware")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23 08:22:49 +01:00
David S. Miller
55793d2a43 Here are two batman-adv bugfixes:
* Fix free/alloc race for OGM and OGMv2, by Sven Eckelmann (2 patches)
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Merge tag 'batadv-net-for-davem-20191025' of git://git.open-mesh.org/linux-merge

Simon Wunderlich says:

====================
Here are two batman-adv bugfixes:

 * Fix free/alloc race for OGM and OGMv2, by Sven Eckelmann (2 patches)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-28 16:39:07 -07:00
Taehee Yoo
ab92d68fc2 net: core: add generic lockdep keys
Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
   - qdisc_running, xmit, addr_list, qdisc_busylock
   - these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
   - alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
   - free_netdev()
d) Add generic lockdep key helper function
   - netdev_register_lockdep_key()
   - netdev_unregister_lockdep_key()
   - netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-24 14:53:48 -07:00
Sven Eckelmann
40e220b421 batman-adv: Avoid free/alloc race when handling OGM buffer
Each slave interface of an B.A.T.M.A.N. IV virtual interface has an OGM
packet buffer which is initialized using data from netdevice notifier and
other rtnetlink related hooks. It is sent regularly via various slave
interfaces of the batadv virtual interface and in this process also
modified (realloced) to integrate additional state information via TVLV
containers.

It must be avoided that the worker item is executed without a common lock
with the netdevice notifier/rtnetlink helpers. Otherwise it can either
happen that half modified/freed data is sent out or functions modifying the
OGM buffer try to access already freed memory regions.

Reported-by: syzbot+0cc629f19ccb8534935b@syzkaller.appspotmail.com
Fixes: c6c8fea297 ("net: Add batman-adv meshing protocol")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-10-13 21:00:07 +02:00
Sven Eckelmann
a8d23cbbf6 batman-adv: Avoid free/alloc race when handling OGM2 buffer
A B.A.T.M.A.N. V virtual interface has an OGM2 packet buffer which is
initialized using data from the netdevice notifier and other rtnetlink
related hooks. It is sent regularly via various slave interfaces of the
batadv virtual interface and in this process also modified (realloced) to
integrate additional state information via TVLV containers.

It must be avoided that the worker item is executed without a common lock
with the netdevice notifier/rtnetlink helpers. Otherwise it can either
happen that half modified data is sent out or the functions modifying the
OGM2 buffer try to access already freed memory regions.

Fixes: 0da0035942 ("batman-adv: OGMv2 - add basic infrastructure")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-10-13 20:36:39 +02:00
Florian Westphal
895b5c9f20 netfilter: drop bridge nf reset from nf_reset
commit 174e23810c
("sk_buff: drop all skb extensions on free and skb scrubbing") made napi
recycle always drop skb extensions.  The additional skb_ext_del() that is
performed via nf_reset on napi skb recycle is not needed anymore.

Most nf_reset() calls in the stack are there so queued skb won't block
'rmmod nf_conntrack' indefinitely.

This removes the skb_ext_del from nf_reset, and renames it to a more
fitting nf_reset_ct().

In a few selected places, add a call to skb_ext_reset to make sure that
no active extensions remain.

I am submitting this for "net", because we're still early in the release
cycle.  The patch applies to net-next too, but I think the rename causes
needless divergence between those trees.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-01 18:42:15 +02:00
Krzysztof Kozlowski
bf69abad27 net: Fix Kconfig indentation
Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
    $ sed -e 's/^        /\t/' -i */Kconfig

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-26 08:56:17 +02:00
David S. Miller
765b7590c9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
r8152 conflicts are the NAPI fixes in 'net' overlapping with
some tasklet stuff in net-next

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-02 11:20:17 -07:00
David S. Miller
68aaf44595 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor conflict in r8169, bug fix had two versions in net
and net-next, take the net-next hunks.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-27 14:23:31 -07:00
Sven Eckelmann
0ff0f15a32 batman-adv: Only read OGM2 tvlv_len after buffer len check
Multiple batadv_ogm2_packet can be stored in an skbuff. The functions
batadv_v_ogm_send_to_if() uses batadv_v_ogm_aggr_packet() to check if there
is another additional batadv_ogm2_packet in the skb or not before they
continue processing the packet.

The length for such an OGM2 is BATADV_OGM2_HLEN +
batadv_ogm2_packet->tvlv_len. The check must first check that at least
BATADV_OGM2_HLEN bytes are available before it accesses tvlv_len (which is
part of the header. Otherwise it might try read outside of the currently
available skbuff to get the content of tvlv_len.

Fixes: 9323158ef9 ("batman-adv: OGMv2 - implement originators logic")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-08-23 18:20:31 +02:00
Sven Eckelmann
a15d56a607 batman-adv: Only read OGM tvlv_len after buffer len check
Multiple batadv_ogm_packet can be stored in an skbuff. The functions
batadv_iv_ogm_send_to_if()/batadv_iv_ogm_receive() use
batadv_iv_ogm_aggr_packet() to check if there is another additional
batadv_ogm_packet in the skb or not before they continue processing the
packet.

The length for such an OGM is BATADV_OGM_HLEN +
batadv_ogm_packet->tvlv_len. The check must first check that at least
BATADV_OGM_HLEN bytes are available before it accesses tvlv_len (which is
part of the header. Otherwise it might try read outside of the currently
available skbuff to get the content of tvlv_len.

Fixes: ef26157747 ("batman-adv: tvlv - basic infrastructure")
Reported-by: syzbot+355cab184197dbbfa384@syzkaller.appspotmail.com
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-08-23 18:20:17 +02:00
David S. Miller
446bf64b61 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge conflict of mlx5 resolved using instructions in merge
commit 9566e650bf.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-19 11:54:03 -07:00
Eric Dumazet
3ee1bb7aae batman-adv: fix uninit-value in batadv_netlink_get_ifindex()
batadv_netlink_get_ifindex() needs to make sure user passed
a correct u32 attribute.

syzbot reported :
BUG: KMSAN: uninit-value in batadv_netlink_dump_hardif+0x70d/0x880 net/batman-adv/netlink.c:968
CPU: 1 PID: 11705 Comm: syz-executor888 Not tainted 5.1.0+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x191/0x1f0 lib/dump_stack.c:113
 kmsan_report+0x130/0x2a0 mm/kmsan/kmsan.c:622
 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310
 batadv_netlink_dump_hardif+0x70d/0x880 net/batman-adv/netlink.c:968
 genl_lock_dumpit+0xc6/0x130 net/netlink/genetlink.c:482
 netlink_dump+0xa84/0x1ab0 net/netlink/af_netlink.c:2253
 __netlink_dump_start+0xa3a/0xb30 net/netlink/af_netlink.c:2361
 genl_family_rcv_msg net/netlink/genetlink.c:550 [inline]
 genl_rcv_msg+0xfc1/0x1a40 net/netlink/genetlink.c:627
 netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2486
 genl_rcv+0x63/0x80 net/netlink/genetlink.c:638
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x127e/0x12f0 net/netlink/af_netlink.c:1926
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:661 [inline]
 ___sys_sendmsg+0xcc6/0x1200 net/socket.c:2260
 __sys_sendmsg net/socket.c:2298 [inline]
 __do_sys_sendmsg net/socket.c:2307 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2305
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2305
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x440209

Fixes: b60620cf56 ("batman-adv: netlink: hardif query")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-08-14 19:27:07 +02:00
Linus Lüssing
9cb9a17813 batman-adv: BATMAN_V: aggregate OGMv2 packets
Instead of transmitting individual OGMv2 packets from the aggregation
queue merge those OGMv2 packets into a single one and transmit this
aggregate instead.

This reduces overhead as it saves an ethernet header and a transmission
per aggregated OGMv2 packet.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
2019-08-04 22:22:00 +02:00