linux-stable.git/net/core, branch v4.19.48

jump_label: move 'asm goto' support test to Kconfig

2019-06-04T06:02:34+00:00

commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream.

Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".

The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:

  #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
  # define HAVE_JUMP_LABEL
  #endif

We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.

Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.

Signed-off-by: Masahiro Yamada 
Acked-by: Michael Ellerman  (powerpc)
Tested-by: Sedat Dilek 
[nc: Fix trivial conflicts in 4.19
     arch/xtensa/kernel/jump_label.c doesn't exist yet
     Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently
     eliminated]
Signed-off-by: Nathan Chancellor 
Signed-off-by: Greg Kroah-Hartman

net-gro: fix use-after-free read in napi_gro_frags()

2019-06-04T06:02:32+00:00

[ Upstream commit a4270d6795b0580287453ea55974d948393e66ef ]

If a network driver provides to napi_gro_frags() an
skb with a page fragment of exactly 14 bytes, the call
to gro_pull_from_frag0() will 'consume' the fragment
by calling skb_frag_unref(skb, 0), and the page might
be freed and reused.

Reading eth->h_proto at the end of napi_frags_skb() might
read mangled data, or crash under specific debugging features.

BUG: KASAN: use-after-free in napi_frags_skb net/core/dev.c:5833 [inline]
BUG: KASAN: use-after-free in napi_gro_frags+0xc6f/0xd10 net/core/dev.c:5841
Read of size 2 at addr ffff88809366840c by task syz-executor599/8957

CPU: 1 PID: 8957 Comm: syz-executor599 Not tainted 5.2.0-rc1+ #32
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+0x172/0x1f0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188
 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 kasan_report+0x12/0x20 mm/kasan/common.c:614
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/generic_report.c:142
 napi_frags_skb net/core/dev.c:5833 [inline]
 napi_gro_frags+0xc6f/0xd10 net/core/dev.c:5841
 tun_get_user+0x2f3c/0x3ff0 drivers/net/tun.c:1991
 tun_chr_write_iter+0xbd/0x156 drivers/net/tun.c:2037
 call_write_iter include/linux/fs.h:1872 [inline]
 do_iter_readv_writev+0x5f8/0x8f0 fs/read_write.c:693
 do_iter_write fs/read_write.c:970 [inline]
 do_iter_write+0x184/0x610 fs/read_write.c:951
 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1015
 do_writev+0x15b/0x330 fs/read_write.c:1058

Fixes: a50e233c50db ("net-gro: restore frag0 optimization")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

bpf: add bpf_jit_limit knob to restrict unpriv allocations

2019-05-31T13:46:03+00:00

commit ede95a63b5e84ddeea6b0c473b36ab8bfd8c6ce3 upstream.

Rick reported that the BPF JIT could potentially fill the entire module
space with BPF programs from unprivileged users which would prevent later
attempts to load normal kernel modules or privileged BPF programs, for
example. If JIT was enabled but unsuccessful to generate the image, then
before commit 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config")
we would always fall back to the BPF interpreter. Nowadays in the case
where the CONFIG_BPF_JIT_ALWAYS_ON could be set, then the load will abort
with a failure since the BPF interpreter was compiled out.

Add a global limit and enforce it for unprivileged users such that in case
of BPF interpreter compiled out we fail once the limit has been reached
or we fall back to BPF interpreter earlier w/o using module mem if latter
was compiled in. In a next step, fair share among unprivileged users can
be resolved in particular for the case where we would fail hard once limit
is reached.

Fixes: 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config")
Fixes: 0a14842f5a3c ("net: filter: Just In Time compiler for x86-64")
Co-Developed-by: Rick Edgecombe 
Signed-off-by: Daniel Borkmann 
Acked-by: Alexei Starovoitov 
Cc: Eric Dumazet 
Cc: Jann Horn 
Cc: Kees Cook 
Cc: LKML 
Signed-off-by: Alexei Starovoitov 
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

rtnetlink: always put IFLA_LINK for links with a link-netnsid

2019-05-25T16:23:21+00:00

[ Upstream commit feadc4b6cf42a53a8a93c918a569a0b7e62bd350 ]

Currently, nla_put_iflink() doesn't put the IFLA_LINK attribute when
iflink == ifindex.

In some cases, a device can be created in a different netns with the
same ifindex as its parent. That device will not dump its IFLA_LINK
attribute, which can confuse some userspace software that expects it.
For example, if the last ifindex created in init_net and foo are both
8, these commands will trigger the issue:

    ip link add parent type dummy                   # ifindex 9
    ip link add link parent netns foo type macvlan  # ifindex 9 in ns foo

So, in case a device puts the IFLA_LINK_NETNSID attribute in a dump,
always put the IFLA_LINK attribute as well.

Thanks to Dan Winship for analyzing the original OpenShift bug down to
the missing netlink attribute.

v2: change Fixes tag, it's been here forever, as Nicolas Dichtel said
    add Nicolas' ack
v3: change Fixes tag
    fix subject typo, spotted by Edward Cree

Analyzed-by: Dan Winship 
Fixes: d8a5ec672768 ("[NET]: netlink support for moving devices between network namespaces.")
Signed-off-by: Sabrina Dubroca 
Acked-by: Nicolas Dichtel 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: avoid weird emergency message

2019-05-25T16:23:19+00:00

[ Upstream commit d7c04b05c9ca14c55309eb139430283a45c4c25f ]

When host is under high stress, it is very possible thread
running netdev_wait_allrefs() returns from msleep(250)
10 seconds late.

This leads to these messages in the syslog :

[...] unregister_netdevice: waiting for syz_tun to become free. Usage count = 0

If the device refcount is zero, the wait is over.

Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

fib_rules: return 0 directly if an exactly same rule exists when NLM_F_EXCL not supplied

2019-05-16T17:41:29+00:00

[ Upstream commit e9919a24d3022f72bcadc407e73a6ef17093a849 ]

With commit 153380ec4b9 ("fib_rules: Added NLM_F_EXCL support to
fib_nl_newrule") we now able to check if a rule already exists. But this
only works with iproute2. For other tools like libnl, NetworkManager,
it still could add duplicate rules with only NLM_F_CREATE flag, like

[localhost ~ ]# ip rule
0:      from all lookup local
32766:  from all lookup main
32767:  from all lookup default
100000: from 192.168.7.5 lookup 5
100000: from 192.168.7.5 lookup 5

As it doesn't make sense to create two duplicate rules, let's just return
0 if the rule exists.

Fixes: 153380ec4b9 ("fib_rules: Added NLM_F_EXCL support to fib_nl_newrule")
Reported-by: Thomas Haller 
Signed-off-by: Hangbin Liu 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Fix missing meta data in skb with vlan packet

2019-04-27T07:36:30+00:00

[ Upstream commit d85e8be2a5a02869f815dd0ac2d743deb4cd7957 ]

skb_reorder_vlan_header() should move XDP meta data with ethernet header
if XDP meta data exists.

Fixes: de8f3a83b0a0 ("bpf: add meta pointer for direct access")
Signed-off-by: Yuya Kusakabe 
Signed-off-by: Takeru Hayasaka 
Co-developed-by: Takeru Hayasaka 
Reviewed-by: Toshiaki Makita 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

failover: allow name change on IFF_UP slave interfaces

2019-04-27T07:36:30+00:00

[ Upstream commit 8065a779f17e94536a1c4dcee4f9d88011672f97 ]

When a netdev appears through hot plug then gets enslaved by a failover
master that is already up and running, the slave will be opened
right away after getting enslaved. Today there's a race that userspace
(udev) may fail to rename the slave if the kernel (net_failover)
opens the slave earlier than when the userspace rename happens.
Unlike bond or team, the primary slave of failover can't be renamed by
userspace ahead of time, since the kernel initiated auto-enslavement is
unable to, or rather, is never meant to be synchronized with the rename
request from userspace.

As the failover slave interfaces are not designed to be operated
directly by userspace apps: IP configuration, filter rules with
regard to network traffic passing and etc., should all be done on master
interface. In general, userspace apps only care about the
name of master interface, while slave names are less important as long
as admin users can see reliable names that may carry
other information describing the netdev. For e.g., they can infer that
"ens3nsby" is a standby slave of "ens3", while for a
name like "eth0" they can't tell which master it belongs to.

Historically the name of IFF_UP interface can't be changed because
there might be admin script or management software that is already
relying on such behavior and assumes that the slave name can't be
changed once UP. But failover is special: with the in-kernel
auto-enslavement mechanism, the userspace expectation for device
enumeration and bring-up order is already broken. Previously initramfs
and various userspace config tools were modified to bypass failover
slaves because of auto-enslavement and duplicate MAC address. Similarly,
in case that users care about seeing reliable slave name, the new type
of failover slaves needs to be taken care of specifically in userspace
anyway.

It's less risky to lift up the rename restriction on failover slave
which is already UP. Although it's possible this change may potentially
break userspace component (most likely configuration scripts or
management software) that assumes slave name can't be changed while
UP, it's relatively a limited and controllable set among all userspace
components, which can be fixed specifically to listen for the rename
events on failover slaves. Userspace component interacting with slaves
is expected to be changed to operate on failover master interface
instead, as the failover slave is dynamic in nature which may come and
go at any point.  The goal is to make the role of failover slaves less
relevant, and userspace components should only deal with failover master
in the long run.

Fixes: 30c8bd5aa8b2 ("net: Introduce generic failover module")
Signed-off-by: Si-Wei Liu 
Reviewed-by: Liran Alon 
Acked-by: Sridhar Samudrala 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: core: netif_receive_skb_list: unlist skb before passing to pt->func

2019-04-17T06:38:43+00:00

[ Upstream commit 9a5a90d167b0e5fe3d47af16b68fd09ce64085cd ]

__netif_receive_skb_list_ptype() leaves skb->next poisoned before passing
it to pt_prev->func handler, what may produce (in certain cases, e.g. DSA
setup) crashes like:

[ 88.606777] CPU 0 Unable to handle kernel paging request at virtual address 0000000e, epc == 80687078, ra == 8052cc7c
[ 88.618666] Oops[#1]:
[ 88.621196] CPU: 0 PID: 0 Comm: swapper Not tainted 5.1.0-rc2-dlink-00206-g4192a172-dirty #1473
[ 88.630885] $ 0 : 00000000 10000400 00000002 864d7850
[ 88.636709] $ 4 : 87c0ddf0 864d7800 87c0ddf0 00000000
[ 88.642526] $ 8 : 00000000 49600000 00000001 00000001
[ 88.648342] $12 : 00000000 c288617b dadbee27 25d17c41
[ 88.654159] $16 : 87c0ddf0 85cff080 80790000 fffffffd
[ 88.659975] $20 : 80797b20 ffffffff 00000001 864d7800
[ 88.665793] $24 : 00000000 8011e658
[ 88.671609] $28 : 80790000 87c0dbc0 87cabf00 8052cc7c
[ 88.677427] Hi : 00000003
[ 88.680622] Lo : 7b5b4220
[ 88.683840] epc : 80687078 vlan_dev_hard_start_xmit+0x1c/0x1a0
[ 88.690532] ra : 8052cc7c dev_hard_start_xmit+0xac/0x188
[ 88.696734] Status: 10000404	IEp
[ 88.700422] Cause : 50000008 (ExcCode 02)
[ 88.704874] BadVA : 0000000e
[ 88.708069] PrId : 0001a120 (MIPS interAptiv (multi))
[ 88.713005] Modules linked in:
[ 88.716407] Process swapper (pid: 0, threadinfo=(ptrval), task=(ptrval), tls=00000000)
[ 88.725219] Stack : 85f61c28 00000000 0000000e 80780000 87c0ddf0 85cff080 80790000 8052cc7c
[ 88.734529] 87cabf00 00000000 00000001 85f5fb40 807b0000 864d7850 87cabf00 807d0000
[ 88.743839] 864d7800 8655f600 00000000 85cff080 87c1c000 0000006a 00000000 8052d96c
[ 88.753149] 807a0000 8057adb8 87c0dcc8 87c0dc50 85cfff08 00000558 87cabf00 85f58c50
[ 88.762460] 00000002 85f58c00 864d7800 80543308 fffffff4 00000001 85f58c00 864d7800
[ 88.771770] ...
[ 88.774483] Call Trace:
[ 88.777199] [<80687078>] vlan_dev_hard_start_xmit+0x1c/0x1a0
[ 88.783504] [<8052cc7c>] dev_hard_start_xmit+0xac/0x188
[ 88.789326] [<8052d96c>] __dev_queue_xmit+0x6e8/0x7d4
[ 88.794955] [<805a8640>] ip_finish_output2+0x238/0x4d0
[ 88.800677] [<805ab6a0>] ip_output+0xc8/0x140
[ 88.805526] [<805a68f4>] ip_forward+0x364/0x560
[ 88.810567] [<805a4ff8>] ip_rcv+0x48/0xe4
[ 88.815030] [<80528d44>] __netif_receive_skb_one_core+0x44/0x58
[ 88.821635] [<8067f220>] dsa_switch_rcv+0x108/0x1ac
[ 88.827067] [<80528f80>] __netif_receive_skb_list_core+0x228/0x26c
[ 88.833951] [<8052ed84>] netif_receive_skb_list+0x1d4/0x394
[ 88.840160] [<80355a88>] lunar_rx_poll+0x38c/0x828
[ 88.845496] [<8052fa78>] net_rx_action+0x14c/0x3cc
[ 88.850835] [<806ad300>] __do_softirq+0x178/0x338
[ 88.856077] [<8012a2d4>] irq_exit+0xbc/0x100
[ 88.860846] [<802f8b70>] plat_irq_dispatch+0xc0/0x144
[ 88.866477] [<80105974>] handle_int+0x14c/0x158
[ 88.871516] [<806acfb0>] r4k_wait+0x30/0x40
[ 88.876462] Code: afb10014 8c8200a0 00803025 <9443000c> 94a20468 00000000 10620042 00a08025 9605046a
[ 88.887332]
[ 88.888982] ---[ end trace eb863d007da11cf1 ]---
[ 88.894122] Kernel panic - not syncing: Fatal exception in interrupt
[ 88.901202] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---

Fix this by pulling skb off the sublist and zeroing skb->next pointer
before calling ptype callback.

Fixes: 88eb1944e18c ("net: core: propagate SKB lists through packet_type lookup")
Reviewed-by: Edward Cree 
Signed-off-by: Alexander Lobakin 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

netns: provide pure entropy for net_hash_mix()

2019-04-17T06:38:40+00:00

[ Upstream commit 355b98553789b646ed97ad801a619ff898471b92 ]

net_hash_mix() currently uses kernel address of a struct net,
and is used in many places that could be used to reveal this
address to a patient attacker, thus defeating KASLR, for
the typical case (initial net namespace, &init_net is
not dynamically allocated)

I believe the original implementation tried to avoid spending
too many cycles in this function, but security comes first.

Also provide entropy regardless of CONFIG_NET_NS.

Fixes: 0b4419162aa6 ("netns: introduce the net_hash_mix "salt" for hashes")
Signed-off-by: Eric Dumazet 
Reported-by: Amit Klein 
Reported-by: Benny Pinkas 
Cc: Pavel Emelyanov 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin