linux.git/net/netfilter, branch v4.19.145

netfilter: nfnetlink: nfnetlink_unicast() reports EAGAIN instead of ENOBUFS

2020-09-09T17:04:26+00:00

[ Upstream commit ee921183557af39c1a0475f982d43b0fcac25e2e ]

Frontend callback reports EAGAIN to nfnetlink to retry a command, this
is used to signal that module autoloading is required. Unfortunately,
nlmsg_unicast() reports EAGAIN in case the receiver socket buffer gets
full, so it enters a busy-loop.

This patch updates nfnetlink_unicast() to turn EAGAIN into ENOBUFS and
to use nlmsg_unicast(). Remove the flags field in nfnetlink_unicast()
since this is always MSG_DONTWAIT in the existing code which is exactly
what nlmsg_unicast() passes to netlink_unicast() as parameter.

Fixes: 96518518cc41 ("netfilter: add nftables")
Reported-by: Phil Sutter 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_tables: fix destination register zeroing

2020-09-09T17:04:25+00:00

[ Upstream commit 1e105e6afa6c3d32bfb52c00ffa393894a525c27 ]

Following bug was reported via irc:
nft list ruleset
   set knock_candidates_ipv4 {
      type ipv4_addr . inet_service
      size 65535
      elements = { 127.0.0.1 . 123,
                   127.0.0.1 . 123 }
      }
 ..
   udp dport 123 add @knock_candidates_ipv4 { ip saddr . 123 }
   udp dport 123 add @knock_candidates_ipv4 { ip saddr . udp dport }

It should not have been possible to add a duplicate set entry.

After some debugging it turned out that the problem is the immediate
value (123) in the second-to-last rule.

Concatenations use 32bit registers, i.e. the elements are 8 bytes each,
not 6 and it turns out the kernel inserted

inet firewall @knock_candidates_ipv4
        element 0100007f ffff7b00  : 0 [end]
        element 0100007f 00007b00  : 0 [end]

Note the non-zero upper bits of the first element.  It turns out that
nft_immediate doesn't zero the destination register, but this is needed
when the length isn't a multiple of 4.

Furthermore, the zeroing in nft_payload is broken.  We can't use
[len / 4] = 0 -- if len is a multiple of 4, index is off by one.

Skip zeroing in this case and use a conditional instead of (len -1) / 4.

Fixes: 49499c3e6e18 ("netfilter: nf_tables: switch registers to 32 bit addressing")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_tables: add NFTA_SET_USERDATA if not null

2020-09-09T17:04:24+00:00

[ Upstream commit 6f03bf43ee05b31d3822def2a80f11b3591c55b3 ]

Kernel sends an empty NFTA_SET_USERDATA attribute with no value if
userspace adds a set with no NFTA_SET_USERDATA attribute.

Fixes: e6d8ecac9e68 ("netfilter: nf_tables: Add new attributes into nft_set to store user data.")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: allow connection reuse for unconfirmed conntrack

2020-08-19T06:14:56+00:00

[ Upstream commit f0a5e4d7a594e0fe237d3dfafb069bb82f80f42f ]

YangYuxi is reporting that connection reuse
is causing one-second delay when SYN hits
existing connection in TIME_WAIT state.
Such delay was added to give time to expire
both the IPVS connection and the corresponding
conntrack. This was considered a rare case
at that time but it is causing problem for
some environments such as Kubernetes.

As nf_conntrack_tcp_packet() can decide to
release the conntrack in TIME_WAIT state and
to replace it with a fresh NEW conntrack, we
can use this to allow rescheduling just by
tuning our check: if the conntrack is
confirmed we can not schedule it to different
real server and the one-second delay still
applies but if new conntrack was created,
we are free to select new real server without
any delays.

YangYuxi lists some of the problem reports:

- One second connection delay in masquerading mode:
https://marc.info/?t=151683118100004&r=1&w=2

- IPVS low throughput #70747
https://github.com/kubernetes/kubernetes/issues/70747

- Apache Bench can fill up ipvs service proxy in seconds #544
https://github.com/cloudnativelabs/kube-router/issues/544

- Additional 1s latency in `host -> service IP -> pod`
https://github.com/kubernetes/kubernetes/issues/90854

Fixes: f719e3754ee2 ("ipvs: drop first packet to redirect conntrack")
Co-developed-by: YangYuxi 
Signed-off-by: YangYuxi 
Signed-off-by: Julian Anastasov 
Reviewed-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: fix the connection sync failed in some cases

2020-07-29T08:16:50+00:00

[ Upstream commit 8210e344ccb798c672ab237b1a4f241bda08909b ]

The sync_thread_backup only checks sk_receive_queue is empty or not,
there is a situation which cannot sync the connection entries when
sk_receive_queue is empty and sk_rmem_alloc is larger than sk_rcvbuf,
the sync packets are dropped in __udp_enqueue_schedule_skb, this is
because the packets in reader_queue is not read, so the rmem is
not reclaimed.

Here I add the check of whether the reader_queue of the udp sock is
empty or not to solve this problem.

Fixes: 2276f58ac589 ("udp: use a separate rx queue for packet reception")
Reported-by: zhouxudong 
Signed-off-by: guodeqing 
Acked-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: ipset: fix unaligned atomic access

2020-07-01T03:17:12+00:00

[ Upstream commit 715028460082d07a7ec6fcd87b14b46784346a72 ]

When using ip_set with counters and comment, traffic causes the kernel
to panic on 32-bit ARM:

Alignment trap: not handling instruction e1b82f9f at []
Unhandled fault: alignment exception (0x221) at 0xea08133c
PC is at ip_set_match_extensions+0xe0/0x224 [ip_set]

The problem occurs when we try to update the 64-bit counters - the
faulting address above is not 64-bit aligned.  The problem occurs
due to the way elements are allocated, for example:

	set->dsize = ip_set_elem_len(set, tb, 0, 0);
	map = ip_set_alloc(sizeof(*map) + elements * set->dsize);

If the element has a requirement for a member to be 64-bit aligned,
and set->dsize is not a multiple of 8, but is a multiple of four,
then every odd numbered elements will be misaligned - and hitting
an atomic64_add() on that element will cause the kernel to panic.

ip_set_elem_len() must return a size that is rounded to the maximum
alignment of any extension field stored in the element.  This change
ensures that is the case.

Fixes: 95ad1f4a9358 ("netfilter: ipset: Fix extension alignment")
Signed-off-by: Russell King 
Acked-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nft_nat: return EOPNOTSUPP if type or flags are not supported

2020-06-22T07:05:14+00:00

[ Upstream commit 0d7c83463fdf7841350f37960a7abadd3e650b41 ]

Instead of EINVAL which should be used for malformed netlink messages.

Fixes: eb31628e37a0 ("netfilter: nf_tables: Add support for IPv6 NAT")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_conntrack_pptp: fix compilation warning with W=1 build

2020-06-03T06:19:49+00:00

commit 4946ea5c1237036155c3b3a24f049fd5f849f8f6 upstream.

>> include/linux/netfilter/nf_conntrack_pptp.h:13:20: warning: 'const' type qualifier on return type has no effect [-Wignored-qualifiers]
extern const char *const pptp_msg_name(u_int16_t msg);
^~~~~~

Reported-by: kbuild test robot 
Fixes: 4c559f15efcc ("netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code

2020-06-03T06:19:47+00:00

commit 4c559f15efcc43b996f4da528cd7f9483aaca36d upstream.

Dan Carpenter says: "Smatch complains that the value for "cmd" comes
from the network and can't be trusted."

Add pptp_msg_name() helper function that checks for the array boundary.

Fixes: f09943fefe6b ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port")
Reported-by: Dan Carpenter 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nfnetlink_cthelper: unbreak userspace helper support

2020-06-03T06:19:47+00:00

commit 703acd70f2496537457186211c2f03e792409e68 upstream.

Restore helper data size initialization and fix memcopy of the helper
data size.

Fixes: 157ffffeb5dc ("netfilter: nfnetlink_cthelper: reject too large userspace allocation requests")
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman