linux-stable.git/net/sched, branch linux-5.17.y

net/sched: act_police: more accurate MTU policing

2022-06-14T16:41:52+00:00

commit 4ddc844eb81da59bfb816d8d52089aba4e59e269 upstream.

in current Linux, MTU policing does not take into account that packets at
the TC ingress have the L2 header pulled. Thus, the same TC police action
(with the same value of tcfp_mtu) behaves differently for ingress/egress.
In addition, the full GSO size is compared to tcfp_mtu: as a consequence,
the policer drops GSO packets even when individual segments have the L2 +
L3 + L4 + payload length below the configured valued of tcfp_mtu.

Improve the accuracy of MTU policing as follows:
 - account for mac_len for non-GSO packets at TC ingress.
 - compare MTU threshold with the segmented size for GSO packets.
Also, add a kselftest that verifies the correct behavior.

Signed-off-by: Davide Caratti 
Reviewed-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/sched: act_pedit: sanitize shift argument before usage

2022-05-25T07:59:06+00:00

[ Upstream commit 4d42d54a7d6aa6d29221d3fd4f2ae9503e94f011 ]

syzbot was able to trigger an Out-of-Bound on the pedit action:

UBSAN: shift-out-of-bounds in net/sched/act_pedit.c:238:43
shift exponent 1400735974 is too large for 32-bit type 'unsigned int'
CPU: 0 PID: 3606 Comm: syz-executor151 Not tainted 5.18.0-rc5-syzkaller-00165-g810c2f0a3f86 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 ubsan_epilogue+0xb/0x50 lib/ubsan.c:151
 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x187 lib/ubsan.c:322
 tcf_pedit_init.cold+0x1a/0x1f net/sched/act_pedit.c:238
 tcf_action_init_1+0x414/0x690 net/sched/act_api.c:1367
 tcf_action_init+0x530/0x8d0 net/sched/act_api.c:1432
 tcf_action_add+0xf9/0x480 net/sched/act_api.c:1956
 tc_ctl_action+0x346/0x470 net/sched/act_api.c:2015
 rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5993
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2502
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x6e2/0x800 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe36e9e1b59
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffef796fe88 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe36e9e1b59
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00007fe36e9a5d00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe36e9a5d90
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 

The 'shift' field is not validated, and any value above 31 will
trigger out-of-bounds. The issue predates the git history, but
syzbot was able to trigger it only after the commit mentioned in
the fixes tag, and this change only applies on top of such commit.

Address the issue bounding the 'shift' value to the maximum allowed
by the relevant operator.

Reported-and-tested-by: syzbot+8ed8fc4c57e9dcf23ca6@syzkaller.appspotmail.com
Fixes: 8b796475fd78 ("net/sched: act_pedit: really ensure the skb is writable")
Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/sched: act_pedit: really ensure the skb is writable

2022-05-18T08:28:15+00:00

[ Upstream commit 8b796475fd7882663a870456466a4fb315cc1bd6 ]

Currently pedit tries to ensure that the accessed skb offset
is writable via skb_unclone(). The action potentially allows
touching any skb bytes, so it may end-up modifying shared data.

The above causes some sporadic MPTCP self-test failures, due to
this code:

	tc -n $ns2 filter add dev ns2eth$i egress \
		protocol ip prio 1000 \
		handle 42 fw \
		action pedit munge offset 148 u8 invert \
		pipe csum tcp \
		index 100

The above modifies a data byte outside the skb head and the skb is
a cloned one, carrying a TCP output packet.

This change addresses the issue by keeping track of a rough
over-estimate highest skb offset accessed by the action and ensuring
such offset is really writable.

Note that this may cause performance regressions in some scenarios,
but hopefully pedit is not in the critical path.

Fixes: db2c24175d14 ("act_pedit: access skb->data safely")
Acked-by: Mat Martineau 
Tested-by: Geliang Tang 
Signed-off-by: Paolo Abeni 
Acked-by: Jamal Hadi Salim 
Link: https://lore.kernel.org/r/1fcf78e6679d0a287dd61bb0f04730ce33b3255d.1652194627.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net/sched: cls_u32: fix possible leak in u32_init_knode()

2022-04-27T12:41:01+00:00

[ Upstream commit ec5b0f605b105457f257f2870acad4a5d463984b ]

While investigating a related syzbot report,
I found that whenever call to tcf_exts_init()
from u32_init_knode() is failing, we end up
with an elevated refcount on ht->refcnt

To avoid that, only increase the refcount after
all possible errors have been evaluated.

Fixes: b9a24bb76bf6 ("net_sched: properly handle failure case of tcf_exts_init()")
Signed-off-by: Eric Dumazet 
Cc: Cong Wang 
Cc: Jiri Pirko 
Acked-by: Jamal Hadi Salim 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net/sched: cls_u32: fix netns refcount changes in u32_change()

2022-04-27T12:40:54+00:00

commit 3db09e762dc79584a69c10d74a6b98f89a9979f8 upstream.

We are now able to detect extra put_net() at the moment
they happen, instead of much later in correct code paths.

u32_init_knode() / tcf_exts_init() populates the ->exts.net
pointer, but as mentioned in tcf_exts_init(),
the refcount on netns has not been elevated yet.

The refcount is taken only once tcf_exts_get_net()
is called.

So the two u32_destroy_key() calls from u32_change()
are attempting to release an invalid reference on the netns.

syzbot report:

refcount_t: decrement hit 0; leaking memory.
WARNING: CPU: 0 PID: 21708 at lib/refcount.c:31 refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Modules linked in:
CPU: 0 PID: 21708 Comm: syz-executor.5 Not tainted 5.18.0-rc2-next-20220412-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:refcount_warn_saturate+0xbf/0x1e0 lib/refcount.c:31
Code: 1d 14 b6 b2 09 31 ff 89 de e8 6d e9 89 fd 84 db 75 e0 e8 84 e5 89 fd 48 c7 c7 40 aa 26 8a c6 05 f4 b5 b2 09 01 e8 e5 81 2e 05 <0f> 0b eb c4 e8 68 e5 89 fd 0f b6 1d e3 b5 b2 09 31 ff 89 de e8 38
RSP: 0018:ffffc900051af1b0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000040000 RSI: ffffffff8160a0c8 RDI: fffff52000a35e28
RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81604a9e R11: 0000000000000000 R12: 1ffff92000a35e3b
R13: 00000000ffffffef R14: ffff8880211a0194 R15: ffff8880577d0a00
FS:  00007f25d183e700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f19c859c028 CR3: 0000000051009000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
 __refcount_dec include/linux/refcount.h:344 [inline]
 refcount_dec include/linux/refcount.h:359 [inline]
 ref_tracker_free+0x535/0x6b0 lib/ref_tracker.c:118
 netns_tracker_free include/net/net_namespace.h:327 [inline]
 put_net_track include/net/net_namespace.h:341 [inline]
 tcf_exts_put_net include/net/pkt_cls.h:255 [inline]
 u32_destroy_key.isra.0+0xa7/0x2b0 net/sched/cls_u32.c:394
 u32_change+0xe01/0x3140 net/sched/cls_u32.c:909
 tc_new_tfilter+0x98d/0x2200 net/sched/cls_api.c:2148
 rtnetlink_rcv_msg+0x80d/0xb80 net/core/rtnetlink.c:6016
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2495
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x904/0xe00 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x6e2/0x800 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2496
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f25d0689049
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f25d183e168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f25d079c030 RCX: 00007f25d0689049
RDX: 0000000000000000 RSI: 0000000020000340 RDI: 0000000000000005
RBP: 00007f25d06e308d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd0b752e3f R14: 00007f25d183e300 R15: 0000000000022000
 

Fixes: 35c55fc156d8 ("cls_u32: use tcf_exts_get_net() before call_rcu()")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Cc: Cong Wang 
Cc: Jiri Pirko 
Acked-by: Jamal Hadi Salim 
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

net/sched: taprio: Check if socket flags are valid

2022-04-20T07:36:14+00:00

[ Upstream commit e8a64bbaaad1f6548cec5508297bc6d45e8ab69e ]

A user may set the SO_TXTIME socket option to ensure a packet is send
at a given time. The taprio scheduler has to confirm, that it is allowed
to send a packet at that given time, by a check against the packet time
schedule. The scheduler drop the packet, if the gates are closed at the
given send time.

The check, if SO_TXTIME is set, may fail since sk_flags are part of an
union and the union is used otherwise. This happen, if a socket is not
a full socket, like a request socket for example.

Add a check to verify, if the union is used for sk_flags.

Fixes: 4cfd5779bd6e ("taprio: Add support for txtime-assist mode")
Signed-off-by: Benedikt Spranger 
Reviewed-by: Kurt Kanzenbach 
Acked-by: Vinicius Costa Gomes 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/sched: fix initialization order when updating chain 0 head

2022-04-20T07:36:13+00:00

[ Upstream commit e65812fd22eba32f11abe28cb377cbd64cfb1ba0 ]

Currently, when inserting a new filter that needs to sit at the head
of chain 0, it will first update the heads pointer on all devices using
the (shared) block, and only then complete the initialization of the new
element so that it has a "next" element.

This can lead to a situation that the chain 0 head is propagated to
another CPU before the "next" initialization is done. When this race
condition is triggered, packets being matched on that CPU will simply
miss all other filters, and will flow through the stack as if there were
no other filters installed. If the system is using OVS + TC, such
packets will get handled by vswitchd via upcall, which results in much
higher latency and reordering. For other applications it may result in
packet drops.

This is reproducible with a tc only setup, but it varies from system to
system. It could be reproduced with a shared block amongst 10 veth
tunnels, and an ingress filter mirroring packets to another veth.
That's because using the last added veth tunnel to the shared block to
do the actual traffic, it makes the race window bigger and easier to
trigger.

The fix is rather simple, to just initialize the next pointer of the new
filter instance (tp) before propagating the head change.

The fixes tag is pointing to the original code though this issue should
only be observed when using it unlocked.

Fixes: 2190d1d0944f ("net: sched: introduce helpers to work with filter chains")
Signed-off-by: Marcelo Ricardo Leitner
Signed-off-by: Vlad Buslov
Reviewed-by: Davide Caratti
Link: https://lore.kernel.org/r/b97d5f4eaffeeb9d058155bcab63347527261abf.1649341369.git.marcelo.leitner@gmail.com
Signed-off-by: Jakub Kicinski
Signed-off-by: Sasha Levin

net/sched: flower: fix parsing of ethertype following VLAN header

2022-04-20T07:36:12+00:00

[ Upstream commit 2105f700b53c24aa48b65c15652acc386044d26a ]

A tc flower filter matching TCA_FLOWER_KEY_VLAN_ETH_TYPE is expected to
match the L2 ethertype following the first VLAN header, as confirmed by
linked discussion with the maintainer. However, such rule also matches
packets that have additional second VLAN header, even though filter has
both eth_type and vlan_ethtype set to "ipv4". Looking at the code this
seems to be mostly an artifact of the way flower uses flow dissector.
First, even though looking at the uAPI eth_type and vlan_ethtype appear
like a distinct fields, in flower they are all mapped to the same
key->basic.n_proto. Second, flow dissector skips following VLAN header as
no keys for FLOW_DISSECTOR_KEY_CVLAN are set and eventually assigns the
value of n_proto to last parsed header. With these, such filters ignore any
headers present between first VLAN header and first "non magic"
header (ipv4 in this case) that doesn't result
FLOW_DISSECT_RET_PROTO_AGAIN.

Fix the issue by extending flow dissector VLAN key structure with new
'vlan_eth_type' field that matches first ethertype following previously
parsed VLAN header. Modify flower classifier to set the new
flow_dissector_key_vlan->vlan_eth_type with value obtained from
TCA_FLOWER_KEY_VLAN_ETH_TYPE/TCA_FLOWER_KEY_CVLAN_ETH_TYPE uAPIs.

Link: https://lore.kernel.org/all/Yjhgi48BpTGh6dig@nanopsycho/
Fixes: 9399ae9a6cb2 ("net_sched: flower: Add vlan support")
Fixes: d64efd0926ba ("net/sched: flower: Add supprt for matching on QinQ vlan headers")
Signed-off-by: Vlad Buslov 
Reviewed-by: Jiri Pirko 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/sched: act_ct: fix ref leak when switching zones

2022-04-08T11:58:35+00:00

[ Upstream commit bcb74e132a76ce0502bb33d5b65533a4ed72d159 ]

When switching zones or network namespaces without doing a ct clear in
between, it is now leaking a reference to the old ct entry. That's
because tcf_ct_skb_nfct_cached() returns false and
tcf_ct_flow_table_lookup() may simply overwrite it.

The fix is to, as the ct entry is not reusable, free it already at
tcf_ct_skb_nfct_cached().

Reported-by: Florian Westphal 
Fixes: 2f131de361f6 ("net/sched: act_ct: Fix flow table lookup after ct clear or switching zones")
Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf

2022-03-01T23:13:47+00:00

Pablo Neira Ayuso says:

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

1) Use kfree_rcu(ptr, rcu) variant, using kfree_rcu(ptr) was not
   intentional. From Eric Dumazet.

2) Use-after-free in netfilter hook core, from Eric Dumazet.

3) Missing rcu read lock side for netfilter egress hook,
   from Florian Westphal.

4) nf_queue assume state->sk is full socket while it might not be.
   Invoke sock_gen_put(), from Florian Westphal.

5) Add selftest to exercise the reported KASAN splat in 4)

6) Fix possible use-after-free in nf_queue in case sk_refcnt is 0.
   Also from Florian.

7) Use input interface index only for hardware offload, not for
   the software plane. This breaks tc ct action. Patch from Paul Blakey.

* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  net/sched: act_ct: Fix flow table lookup failure with no originating ifindex
  netfilter: nf_queue: handle socket prefetch
  netfilter: nf_queue: fix possible use-after-free
  selftests: netfilter: add nfqueue TCP_NEW_SYN_RECV socket race test
  netfilter: nf_queue: don't assume sk is full socket
  netfilter: egress: silence egress hook lockdep splats
  netfilter: fix use-after-free in __nf_register_net_hook()
  netfilter: nf_tables: prefer kfree_rcu(ptr, rcu) variant
====================

Link: https://lore.kernel.org/r/20220301215337.378405-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski