Commit Graph

13324 Commits

Author SHA1 Message Date
Pablo Neira Ayuso
eb014de4fd netfilter: nf_tables: autoload modules from the abort path
This patch introduces a list of pending module requests. This new module
list is composed of nft_module_request objects that contain the module
name and one status field that tells if the module has been already
loaded (the 'done' field).

In the first pass, from the preparation phase, the netlink command finds
that a module is missing on this list. Then, a module request is
allocated and added to this list and nft_request_module() returns
-EAGAIN. This triggers the abort path with the autoload parameter set on
from nfnetlink, request_module() is called and the module request enters
the 'done' state. Since the mutex is released when loading modules from
the abort phase, the module list is zapped so this is iteration occurs
over a local list. Therefore, the request_module() calls happen when
object lists are in consistent state (after fulling aborting the
transaction) and the commit list is empty.

On the second pass, the netlink command will find that it already tried
to load the module, so it does not request it again and
nft_request_module() returns 0. Then, there is a look up to find the
object that the command was missing. If the module was successfully
loaded, the command proceeds normally since it finds the missing object
in place, otherwise -ENOENT is reported to userspace.

This patch also updates nfnetlink to include the reason to enter the
abort phase, which is required for this new autoload module rationale.

Fixes: ec7470b834 ("netfilter: nf_tables: store transaction list locally while requesting module")
Reported-by: syzbot+29125d208b3dae9a7019@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-01-24 20:54:29 +01:00
David S. Miller
3981f955eb Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2020-01-15

The following pull-request contains BPF updates for your *net* tree.

We've added 12 non-merge commits during the last 9 day(s) which contain
a total of 13 files changed, 95 insertions(+), 43 deletions(-).

The main changes are:

1) Fix refcount leak for TCP time wait and request sockets for socket lookup
   related BPF helpers, from Lorenz Bauer.

2) Fix wrong verification of ARSH instruction under ALU32, from Daniel Borkmann.

3) Batch of several sockmap and related TLS fixes found while operating
   more complex BPF programs with Cilium and OpenSSL, from John Fastabend.

4) Fix sockmap to read psock's ingress_msg queue before regular sk_receive_queue()
   to avoid purging data upon teardown, from Lingpeng Chen.

5) Fix printing incorrect pointer in bpftool's btf_dump_ptr() in order to properly
   dump a BPF map's value with BTF, from Martin KaFai Lau.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-16 10:04:40 +01:00
John Fastabend
33bfe20dd7 bpf: Sockmap/tls, push write_space updates through ulp updates
When sockmap sock with TLS enabled is removed we cleanup bpf/psock state
and call tcp_update_ulp() to push updates to TLS ULP on top. However, we
don't push the write_space callback up and instead simply overwrite the
op with the psock stored previous op. This may or may not be correct so
to ensure we don't overwrite the TLS write space hook pass this field to
the ULP and have it fixup the ctx.

This completes a previous fix that pushed the ops through to the ULP
but at the time missed doing this for write_space, presumably because
write_space TLS hook was added around the same time.

Fixes: 95fa145479 ("bpf: sockmap/tls, close can race with map free")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20200111061206.8028-4-john.fastabend@gmail.com
2020-01-15 23:26:13 +01:00
David S. Miller
eb507906fe Merge tag 'mac80211-for-net-2020-01-15' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211
Johannes Berg says:

====================
A few fixes:
 * -O3 enablement fallout, thanks to Arnd who ran this
 * fixes for a few leaks, thanks to Felix
 * channel 12 regulatory fix for custom regdomains
 * check for a crash reported by syzbot
   (NULL function is called on drivers that don't have it)
 * fix TKIP replay protection after setup with some APs
   (from Jouni)
 * restrict obtaining some mesh data to avoid WARN_ONs
 * fix deadlocks with auto-disconnect (socket owner)
 * fix radar detection events with multiple devices
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-15 04:12:00 -08:00
Orr Mazor
26ec17a1dc cfg80211: Fix radar event during another phy CAC
In case a radar event of CAC_FINISHED or RADAR_DETECTED
happens during another phy is during CAC we might need
to cancel that CAC.

If we got a radar in a channel that another phy is now
doing CAC on then the CAC should be canceled there.

If, for example, 2 phys doing CAC on the same channels,
or on comptable channels, once on of them will finish his
CAC the other might need to cancel his CAC, since it is no
longer relevant.

To fix that the commit adds an callback and implement it in
mac80211 to end CAC.
This commit also adds a call to said callback if after a radar
event we see the CAC is no longer relevant

Signed-off-by: Orr Mazor <Orr.Mazor@tandemg.com>
Reviewed-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20191222145449.15792-1-Orr.Mazor@tandemg.com
[slightly reformat/reword commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2020-01-15 09:50:48 +01:00
Jacob Keller
b0efcae5e1 devlink: correct misspelling of snapshot
The function to obtain a unique snapshot id was mistakenly typo'd as
devlink_region_shapshot_id_get. Fix this typo by renaming the function
and all of its users.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-11 14:30:24 -08:00
David S. Miller
b73a65610b Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Missing netns context in arp_tables, from Florian Westphal.

2) Underflow in flowtable reference counter, from wenxu.

3) Fix incorrect ethernet destination address in flowtable offload,
   from wenxu.

4) Check for status of neighbour entry, from wenxu.

5) Fix NAT port mangling, from wenxu.

6) Unbind callbacks from destroy path to cleanup hardware properly
   on flowtable removal.

7) Fix missing casting statistics timestamp, add nf_flowtable_time_stamp
   and use it.

8) NULL pointer exception when timeout argument is null in conntrack
   dccp and sctp protocol helpers, from Florian Westphal.

9) Possible nul-dereference in ipset with IPSET_ATTR_LINENO, also from
   Florian.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-08 15:22:41 -08:00
Pablo Neira Ayuso
fb46f1b780 netfilter: flowtable: add nf_flowtable_time_stamp
This patch adds nf_flowtable_time_stamp and updates the existing code to
use it.

This patch is also implicitly fixing up hardware statistic fetching via
nf_flow_offload_stats() where casting to u32 is missing. Use
nf_flow_timeout_delta() to fix this.

Fixes: c29f74e0df ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: wenxu <wenxu@ucloud.cn>
2020-01-06 10:30:46 +01:00
Davide Caratti
a5b72a083d net/sched: add delete_empty() to filters and use it in cls_flower
Revert "net/sched: cls_u32: fix refcount leak in the error path of
u32_change()", and fix the u32 refcount leak in a more generic way that
preserves the semantic of rule dumping.
On tc filters that don't support lockless insertion/removal, there is no
need to guard against concurrent insertion when a removal is in progress.
Therefore, for most of them we can avoid a full walk() when deleting, and
just decrease the refcount, like it was done on older Linux kernels.
This fixes situations where walk() was wrongly detecting a non-empty
filter, like it happened with cls_u32 in the error path of change(), thus
leading to failures in the following tdc selftests:

 6aa7: (filter, u32) Add/Replace u32 with source match and invalid indev
 6658: (filter, u32) Add/Replace u32 with custom hash table and invalid handle
 74c2: (filter, u32) Add/Replace u32 filter with invalid hash table id

On cls_flower, and on (future) lockless filters, this check is necessary:
move all the check_empty() logic in a callback so that each filter
can have its own implementation. For cls_flower, it's sufficient to check
if no IDRs have been allocated.

This reverts commit 275c44aa19.

Changes since v1:
 - document the need for delete_empty() when TCF_PROTO_OPS_DOIT_UNLOCKED
   is used, thanks to Vlad Buslov
 - implement delete_empty() without doing fl_walk(), thanks to Vlad Buslov
 - squash revert and new fix in a single patch, to be nice with bisect
   tests that run tdc on u32 filter, thanks to Dave Miller

Fixes: 275c44aa19 ("net/sched: cls_u32: fix refcount leak in the error path of u32_change()")
Fixes: 6676d5e416 ("net: sched: set dedicated tcf_walker flag when tp is empty")
Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Suggested-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Vlad Buslov <vladbu@mellanox.com>
Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-30 20:35:19 -08:00
Hangbin Liu
f081042d12 net/dst: do not confirm neighbor for vxlan and geneve pmtu update
When do IPv6 tunnel PMTU update and calls __ip6_rt_update_pmtu() in the end,
we should not call dst_confirm_neigh() as there is no two-way communication.

So disable the neigh confirm for vxlan and geneve pmtu update.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
    dst_ops.update_pmtu to control whether we should do neighbor confirm.
    Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Fixes: a93bf0ff44 ("vxlan: update skb dst pmtu on tx path")
Fixes: 52a589d51f ("geneve: update skb dst pmtu on tx path")
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Tested-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24 22:28:55 -08:00
Hangbin Liu
07dc35c6e3 net/dst: add new function skb_dst_update_pmtu_no_confirm
Add a new function skb_dst_update_pmtu_no_confirm() for callers who need
update pmtu but should not do neighbor confirm.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
    dst_ops.update_pmtu to control whether we should do neighbor confirm.
    Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24 22:28:54 -08:00
Hangbin Liu
bd085ef678 net: add bool confirm_neigh parameter for dst_ops.update_pmtu
The MTU update code is supposed to be invoked in response to real
networking events that update the PMTU. In IPv6 PMTU update function
__ip6_rt_update_pmtu() we called dst_confirm_neigh() to update neighbor
confirmed time.

But for tunnel code, it will call pmtu before xmit, like:
  - tnl_update_pmtu()
    - skb_dst_update_pmtu()
      - ip6_rt_update_pmtu()
        - __ip6_rt_update_pmtu()
          - dst_confirm_neigh()

If the tunnel remote dst mac address changed and we still do the neigh
confirm, we will not be able to update neigh cache and ping6 remote
will failed.

So for this ip_tunnel_xmit() case, _EVEN_ if the MTU is changed, we
should not be invoking dst_confirm_neigh() as we have no evidence
of successful two-way communication at this point.

On the other hand it is also important to keep the neigh reachability fresh
for TCP flows, so we cannot remove this dst_confirm_neigh() call.

To fix the issue, we have to add a new bool parameter for dst_ops.update_pmtu
to choose whether we should do neigh update or not. I will add the parameter
in this patch and set all the callers to true to comply with the previous
way, and fix the tunnel code one by one on later patches.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
    dst_ops.update_pmtu to control whether we should do neighbor confirm.
    Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Suggested-by: David Miller <davem@davemloft.net>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24 22:28:54 -08:00
Linus Torvalds
78bac77b52 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:

 1) Several nf_flow_table_offload fixes from Pablo Neira Ayuso,
    including adding a missing ipv6 match description.

 2) Several heap overflow fixes in mwifiex from qize wang and Ganapathi
    Bhat.

 3) Fix uninit value in bond_neigh_init(), from Eric Dumazet.

 4) Fix non-ACPI probing of nxp-nci, from Stephan Gerhold.

 5) Fix use after free in tipc_disc_rcv(), from Tuong Lien.

 6) Enforce limit of 33 tail calls in mips and riscv JIT, from Paul
    Chaignon.

 7) Multicast MAC limit test is off by one in qede, from Manish Chopra.

 8) Fix established socket lookup race when socket goes from
    TCP_ESTABLISHED to TCP_LISTEN, because there lacks an intervening
    RCU grace period. From Eric Dumazet.

 9) Don't send empty SKBs from tcp_write_xmit(), also from Eric Dumazet.

10) Fix active backup transition after link failure in bonding, from
    Mahesh Bandewar.

11) Avoid zero sized hash table in gtp driver, from Taehee Yoo.

12) Fix wrong interface passed to ->mac_link_up(), from Russell King.

13) Fix DSA egress flooding settings in b53, from Florian Fainelli.

14) Memory leak in gmac_setup_txqs(), from Navid Emamdoost.

15) Fix double free in dpaa2-ptp code, from Ioana Ciornei.

16) Reject invalid MTU values in stmmac, from Jose Abreu.

17) Fix refcount leak in error path of u32 classifier, from Davide
    Caratti.

18) Fix regression causing iwlwifi firmware crashes on boot, from Anders
    Kaseorg.

19) Fix inverted return value logic in llc2 code, from Chan Shu Tak.

20) Disable hardware GRO when XDP is attached to qede, frm Manish
    Chopra.

21) Since we encode state in the low pointer bits, dst metrics must be
    at least 4 byte aligned, which is not necessarily true on m68k. Add
    annotations to fix this, from Geert Uytterhoeven.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (160 commits)
  sfc: Include XDP packet headroom in buffer step size.
  sfc: fix channel allocation with brute force
  net: dst: Force 4-byte alignment of dst_metrics
  selftests: pmtu: fix init mtu value in description
  hv_netvsc: Fix unwanted rx_table reset
  net: phy: ensure that phy IDs are correctly typed
  mod_devicetable: fix PHY module format
  qede: Disable hardware gro when xdp prog is installed
  net: ena: fix issues in setting interrupt moderation params in ethtool
  net: ena: fix default tx interrupt moderation interval
  net/smc: unregister ib devices in reboot_event
  net: stmmac: platform: Fix MDIO init for platforms without PHY
  llc2: Fix return statement of llc_stat_ev_rx_null_dsap_xid_c (and _test_c)
  net: hisilicon: Fix a BUG trigered by wrong bytes_compl
  net: dsa: ksz: use common define for tag len
  s390/qeth: don't return -ENOTSUPP to userspace
  s390/qeth: fix promiscuous mode after reset
  s390/qeth: handle error due to unsupported transport mode
  cxgb4: fix refcount init for TC-MQPRIO offload
  tc-testing: initial tdc selftests for cls_u32
  ...
2019-12-22 09:54:33 -08:00
Geert Uytterhoeven
258a980d1e net: dst: Force 4-byte alignment of dst_metrics
When storing a pointer to a dst_metrics structure in dst_entry._metrics,
two flags are added in the least significant bits of the pointer value.
Hence this assumes all pointers to dst_metrics structures have at least
4-byte alignment.

However, on m68k, the minimum alignment of 32-bit values is 2 bytes, not
4 bytes.  Hence in some kernel builds, dst_default_metrics may be only
2-byte aligned, leading to obscure boot warnings like:

    WARNING: CPU: 0 PID: 7 at lib/refcount.c:28 refcount_warn_saturate+0x44/0x9a
    refcount_t: underflow; use-after-free.
    Modules linked in:
    CPU: 0 PID: 7 Comm: ksoftirqd/0 Tainted: G        W         5.5.0-rc2-atari-01448-g114a1a1038af891d-dirty #261
    Stack from 10835e6c:
	    10835e6c 0038134f 00023fa6 00394b0f 0000001c 00000009 00321560 00023fea
	    00394b0f 0000001c 001a70f8 00000009 00000000 10835eb4 00000001 00000000
	    04208040 0000000a 00394b4a 10835ed4 00043aa8 001a70f8 00394b0f 0000001c
	    00000009 00394b4a 0026aba8 003215a4 00000003 00000000 0026d5a8 00000001
	    003215a4 003a4361 003238d6 000001f0 00000000 003215a4 10aa3b00 00025e84
	    003ddb00 10834000 002416a8 10aa3b00 00000000 00000080 000aa038 0004854a
    Call Trace: [<00023fa6>] __warn+0xb2/0xb4
     [<00023fea>] warn_slowpath_fmt+0x42/0x64
     [<001a70f8>] refcount_warn_saturate+0x44/0x9a
     [<00043aa8>] printk+0x0/0x18
     [<001a70f8>] refcount_warn_saturate+0x44/0x9a
     [<0026aba8>] refcount_sub_and_test.constprop.73+0x38/0x3e
     [<0026d5a8>] ipv4_dst_destroy+0x5e/0x7e
     [<00025e84>] __local_bh_enable_ip+0x0/0x8e
     [<002416a8>] dst_destroy+0x40/0xae

Fix this by forcing 4-byte alignment of all dst_metrics structures.

Fixes: e5fd387ad5 ("ipv6: do not overwrite inetpeer metrics prematurely")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-20 21:54:00 -08:00
Eric Dumazet
7c68fa2bdd net: annotate lockless accesses to sk->sk_pacing_shift
sk->sk_pacing_shift can be read and written without lock
synchronization. This patch adds annotations to
document this fact and avoid future syzbot complains.

This might also avoid unexpected false sharing
in sk_pacing_shift_update(), as the compiler
could remove the conditional check and always
write over sk->sk_pacing_shift :

if (sk->sk_pacing_shift != val)
	sk->sk_pacing_shift = val;

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17 22:09:52 -08:00
Eric Dumazet
ee2aabd3fc tcp: refine tcp_write_queue_empty() implementation
Due to how tcp_sendmsg() is implemented, we can have an empty
skb at the tail of the write queue.

Most [1] tcp_write_queue_empty() callers want to know if there is
anything to send (payload and/or FIN)

Instead of checking if the sk_write_queue is empty, we need
to test if tp->write_seq == tp->snd_nxt

[1] tcp_send_fin() was the only caller that expected to
 see if an skb was in the write queue, I have changed the code
 to reuse the tcp_write_queue_tail() result.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-12-13 21:58:40 -08:00
Eric Dumazet
8dbd76e79a tcp/dccp: fix possible race __inet_lookup_established()
Michal Kubecek and Firo Yang did a very nice analysis of crashes
happening in __inet_lookup_established().

Since a TCP socket can go from TCP_ESTABLISH to TCP_LISTEN
(via a close()/socket()/listen() cycle) without a RCU grace period,
I should not have changed listeners linkage in their hash table.

They must use the nulls protocol (Documentation/RCU/rculist_nulls.txt),
so that a lookup can detect a socket in a hash list was moved in
another one.

Since we added code in commit d296ba60d8 ("soreuseport: Resolve
merge conflict for v4/v6 ordering fix"), we have to add
hlist_nulls_add_tail_rcu() helper.

Fixes: 3b24d854cb ("tcp/dccp: do not touch listener sk_refcnt under synflood")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Reported-by: Firo Yang <firo.yang@suse.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Link: https://lore.kernel.org/netdev/20191120083919.GH27852@unicorn.suse.cz/
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-12-13 21:40:49 -08:00
Pankaj Bharadiya
c593642c8b treewide: Use sizeof_field() macro
Replace all the occurrences of FIELD_SIZEOF() with sizeof_field() except
at places where these are defined. Later patches will remove the unused
definition of FIELD_SIZEOF().

This patch is generated using following script:

EXCLUDE_FILES="include/linux/stddef.h|include/linux/kernel.h"

git grep -l -e "\bFIELD_SIZEOF\b" | while read file;
do

	if [[ "$file" =~ $EXCLUDE_FILES ]]; then
		continue
	fi
	sed -i  -e 's/\bFIELD_SIZEOF\b/sizeof_field/g' $file;
done

Signed-off-by: Pankaj Bharadiya <pankaj.laxminarayan.bharadiya@intel.com>
Link: https://lore.kernel.org/r/20190924105839.110713-3-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David Miller <davem@davemloft.net> # for net
2019-12-09 10:36:44 -08:00
Martin Schiller
f8fc57e8d7 net/x25: add new state X25_STATE_5
This is needed, because if the flag X25_ACCPT_APPRV_FLAG is not set on a
socket (manual call confirmation) and the channel is cleared by remote
before the manual call confirmation was sent, this situation needs to
be handled.

Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-09 10:28:43 -08:00
Eric Dumazet
f394722fb0 neighbour: remove neigh_cleanup() method
neigh_cleanup() has not been used for seven years, and was a wrong design.

Messing with shared pointer in bond_neigh_init() without proper
memory barriers would at least trigger syzbot complains eventually.

It is time to remove this stuff.

Fixes: b63b70d877 ("IPoIB: Use a private hash table for path lookup in xmit path")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-09 09:48:47 -08:00
Eric Dumazet
501a90c945 inet: protect against too small mtu values.
syzbot was once again able to crash a host by setting a very small mtu
on loopback device.

Let's make inetdev_valid_mtu() available in include/net/ip.h,
and use it in ip_setup_cork(), so that we protect both ip_append_page()
and __ip_append_data()

Also add a READ_ONCE() when the device mtu is read.

Pairs this lockless read with one WRITE_ONCE() in __dev_set_mtu(),
even if other code paths might write over this field.

Add a big comment in include/linux/netdevice.h about dev->mtu
needing READ_ONCE()/WRITE_ONCE() annotations.

Hopefully we will add the missing ones in followup patches.

[1]

refcount_t: saturated; leaking memory.
WARNING: CPU: 0 PID: 9464 at lib/refcount.c:22 refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9464 Comm: syz-executor850 Not tainted 5.4.0-syzkaller #0
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+0x197/0x210 lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:221
 __warn.cold+0x2f/0x3e kernel/panic.c:582
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:refcount_warn_saturate+0x138/0x1f0 lib/refcount.c:22
Code: 06 31 ff 89 de e8 c8 f5 e6 fd 84 db 0f 85 6f ff ff ff e8 7b f4 e6 fd 48 c7 c7 e0 71 4f 88 c6 05 56 a6 a4 06 01 e8 c7 a8 b7 fd <0f> 0b e9 50 ff ff ff e8 5c f4 e6 fd 0f b6 1d 3d a6 a4 06 31 ff 89
RSP: 0018:ffff88809689f550 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815e4336 RDI: ffffed1012d13e9c
RBP: ffff88809689f560 R08: ffff88809c50a3c0 R09: fffffbfff15d31b1
R10: fffffbfff15d31b0 R11: ffffffff8ae98d87 R12: 0000000000000001
R13: 0000000000040100 R14: ffff888099041104 R15: ffff888218d96e40
 refcount_add include/linux/refcount.h:193 [inline]
 skb_set_owner_w+0x2b6/0x410 net/core/sock.c:1999
 sock_wmalloc+0xf1/0x120 net/core/sock.c:2096
 ip_append_page+0x7ef/0x1190 net/ipv4/ip_output.c:1383
 udp_sendpage+0x1c7/0x480 net/ipv4/udp.c:1276
 inet_sendpage+0xdb/0x150 net/ipv4/af_inet.c:821
 kernel_sendpage+0x92/0xf0 net/socket.c:3794
 sock_sendpage+0x8b/0xc0 net/socket.c:936
 pipe_to_sendpage+0x2da/0x3c0 fs/splice.c:458
 splice_from_pipe_feed fs/splice.c:512 [inline]
 __splice_from_pipe+0x3ee/0x7c0 fs/splice.c:636
 splice_from_pipe+0x108/0x170 fs/splice.c:671
 generic_splice_sendpage+0x3c/0x50 fs/splice.c:842
 do_splice_from fs/splice.c:861 [inline]
 direct_splice_actor+0x123/0x190 fs/splice.c:1035
 splice_direct_to_actor+0x3b4/0xa30 fs/splice.c:990
 do_splice_direct+0x1da/0x2a0 fs/splice.c:1078
 do_sendfile+0x597/0xd00 fs/read_write.c:1464
 __do_sys_sendfile64 fs/read_write.c:1525 [inline]
 __se_sys_sendfile64 fs/read_write.c:1511 [inline]
 __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441409
Code: e8 ac e8 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffb64c4f78 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441409
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000005
RBP: 0000000000073b8a R08: 0000000000000010 R09: 0000000000000010
R10: 0000000000010001 R11: 0000000000000246 R12: 0000000000402180
R13: 0000000000402210 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fixes: 1470ddf7f8 ("inet: Remove explicit write references to sk/inet in ip_append_data")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-07 11:55:11 -08:00
Guillaume Nault
721c8dafad tcp: Protect accesses to .ts_recent_stamp with {READ,WRITE}_ONCE()
Syncookies borrow the ->rx_opt.ts_recent_stamp field to store the
timestamp of the last synflood. Protect them with READ_ONCE() and
WRITE_ONCE() since reads and writes aren't serialised.

Use of .rx_opt.ts_recent_stamp for storing the synflood timestamp was
introduced by a0f82f64e2 ("syncookies: remove last_synq_overflow from
struct tcp_sock"). But unprotected accesses were already there when
timestamp was stored in .last_synq_overflow.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-06 21:05:14 -08:00
Guillaume Nault
cb44a08f86 tcp: tighten acceptance of ACKs not matching a child socket
When no synflood occurs, the synflood timestamp isn't updated.
Therefore it can be so old that time_after32() can consider it to be
in the future.

That's a problem for tcp_synq_no_recent_overflow() as it may report
that a recent overflow occurred while, in fact, it's just that jiffies
has grown past 'last_overflow' + TCP_SYNCOOKIE_VALID + 2^31.

Spurious detection of recent overflows lead to extra syncookie
verification in cookie_v[46]_check(). At that point, the verification
should fail and the packet dropped. But we should have dropped the
packet earlier as we didn't even send a syncookie.

Let's refine tcp_synq_no_recent_overflow() to report a recent overflow
only if jiffies is within the
[last_overflow, last_overflow + TCP_SYNCOOKIE_VALID] interval. This
way, no spurious recent overflow is reported when jiffies wraps and
'last_overflow' becomes in the future from the point of view of
time_after32().

However, if jiffies wraps and enters the
[last_overflow, last_overflow + TCP_SYNCOOKIE_VALID] interval (with
'last_overflow' being a stale synflood timestamp), then
tcp_synq_no_recent_overflow() still erroneously reports an
overflow. In such cases, we have to rely on syncookie verification
to drop the packet. We unfortunately have no way to differentiate
between a fresh and a stale syncookie timestamp.

In practice, using last_overflow as lower bound is problematic.
If the synflood timestamp is concurrently updated between the time
we read jiffies and the moment we store the timestamp in
'last_overflow', then 'now' becomes smaller than 'last_overflow' and
tcp_synq_no_recent_overflow() returns true, potentially dropping a
valid syncookie.

Reading jiffies after loading the timestamp could fix the problem,
but that'd require a memory barrier. Let's just accommodate for
potential timestamp growth instead and extend the interval using
'last_overflow - HZ' as lower bound.

Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-06 21:05:14 -08:00
Guillaume Nault
04d26e7b15 tcp: fix rejected syncookies due to stale timestamps
If no synflood happens for a long enough period of time, then the
synflood timestamp isn't refreshed and jiffies can advance so much
that time_after32() can't accurately compare them any more.

Therefore, we can end up in a situation where time_after32(now,
last_overflow + HZ) returns false, just because these two values are
too far apart. In that case, the synflood timestamp isn't updated as
it should be, which can trick tcp_synq_no_recent_overflow() into
rejecting valid syncookies.

For example, let's consider the following scenario on a system
with HZ=1000:

  * The synflood timestamp is 0, either because that's the timestamp
    of the last synflood or, more commonly, because we're working with
    a freshly created socket.

  * We receive a new SYN, which triggers synflood protection. Let's say
    that this happens when jiffies == 2147484649 (that is,
    'synflood timestamp' + HZ + 2^31 + 1).

  * Then tcp_synq_overflow() doesn't update the synflood timestamp,
    because time_after32(2147484649, 1000) returns false.
    With:
      - 2147484649: the value of jiffies, aka. 'now'.
      - 1000: the value of 'last_overflow' + HZ.

  * A bit later, we receive the ACK completing the 3WHS. But
    cookie_v[46]_check() rejects it because tcp_synq_no_recent_overflow()
    says that we're not under synflood. That's because
    time_after32(2147484649, 120000) returns false.
    With:
      - 2147484649: the value of jiffies, aka. 'now'.
      - 120000: the value of 'last_overflow' + TCP_SYNCOOKIE_VALID.

    Of course, in reality jiffies would have increased a bit, but this
    condition will last for the next 119 seconds, which is far enough
    to accommodate for jiffie's growth.

Fix this by updating the overflow timestamp whenever jiffies isn't
within the [last_overflow, last_overflow + HZ] range. That shouldn't
have any performance impact since the update still happens at most once
per second.

Now we're guaranteed to have fresh timestamps while under synflood, so
tcp_synq_no_recent_overflow() can safely use it with time_after32() in
such situations.

Stale timestamps can still make tcp_synq_no_recent_overflow() return
the wrong verdict when not under synflood. This will be handled in the
next patch.

For 64 bits architectures, the problem was introduced with the
conversion of ->tw_ts_recent_stamp to 32 bits integer by commit
cca9bab1b7 ("tcp: use monotonic timestamps for PAWS").
The problem has always been there on 32 bits architectures.

Fixes: cca9bab1b7 ("tcp: use monotonic timestamps for PAWS")
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-06 21:05:14 -08:00
John Hurley
dbad340889 net: core: rename indirect block ingress cb function
With indirect blocks, a driver can register for callbacks from a device
that is does not 'own', for example, a tunnel device. When registering to
or unregistering from a new device, a callback is triggered to generate
a bind/unbind event. This, in turn, allows the driver to receive any
existing rules or to properly clean up installed rules.

When first added, it was assumed that all indirect block registrations
would be for ingress offloads. However, the NFP driver can, in some
instances, support clsact qdisc binds for egress offload.

Change the name of the indirect block callback command in flow_offload to
remove the 'ingress' identifier from it. While this does not change
functionality, a follow up patch will implement a more more generic
callback than just those currently just supporting ingress offload.

Fixes: 4d12ba4278 ("nfp: flower: allow offloading of matches on 'internal' ports")
Signed-off-by: John Hurley <john.hurley@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-06 20:45:09 -08:00