linux-stable.git/include/net, branch v4.14.129

tcp: add tcp_min_snd_mss sysctl

2019-06-17T17:52:44+00:00

commit 5f3e2bf008c2221478101ee72f5cb4654b9fc363 upstream.

Some TCP peers announce a very small MSS option in their SYN and/or
SYN/ACK messages.

This forces the stack to send packets with a very high network/cpu
overhead.

Linux has enforced a minimal value of 48. Since this value includes
the size of TCP options, and that the options can consume up to 40
bytes, this means that each segment can include only 8 bytes of payload.

In some cases, it can be useful to increase the minimal value
to a saner value.

We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility
reasons.

Note that TCP_MAXSEG socket option enforces a minimal value
of (TCP_MIN_MSS). David Miller increased this minimal value
in commit c39508d6f118 ("tcp: Make TCP_MAXSEG minimum more correct.")
from 64 to 88.

We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS.

CVE-2019-11479 -- tcp mss hardcoded to 48

Signed-off-by: Eric Dumazet 
Suggested-by: Jonathan Looney 
Acked-by: Neal Cardwell 
Cc: Yuchung Cheng 
Cc: Tyler Hicks 
Cc: Bruce Curtis 
Cc: Jonathan Lemon 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: limit payload size of sacked skbs

2019-06-17T17:52:43+00:00

commit 3b4929f65b0d8249f19a50245cd88ed1a2f78cff upstream.

Jonathan Looney reported that TCP can trigger the following crash
in tcp_shifted_skb() :

	BUG_ON(tcp_skb_pcount(skb) < pcount);

This can happen if the remote peer has advertized the smallest
MSS that linux TCP accepts : 48

An skb can hold 17 fragments, and each fragment can hold 32KB
on x86, or 64KB on PowerPC.

This means that the 16bit witdh of TCP_SKB_CB(skb)->tcp_gso_segs
can overflow.

Note that tcp_sendmsg() builds skbs with less than 64KB
of payload, so this problem needs SACK to be enabled.
SACK blocks allow TCP to coalesce multiple skbs in the retransmit
queue, thus filling the 17 fragments to maximal capacity.

CVE-2019-11477 -- u16 overflow of TCP_SKB_CB(skb)->tcp_gso_segs

Backport notes, provided by Joao Martins 

v4.15 or since commit 737ff314563 ("tcp: use sequence distance to
detect reordering") had switched from the packet-based FACK tracking and
switched to sequence-based.

v4.14 and older still have the old logic and hence on
tcp_skb_shift_data() needs to retain its original logic and have
@fack_count in sync. In other words, we keep the increment of pcount with
tcp_skb_pcount(skb) to later used that to update fack_count. To make it
more explicit we track the new skb that gets incremented to pcount in
@next_pcount, and we get to avoid the constant invocation of
tcp_skb_pcount(skb) all together.

Fixes: 832d11c5cd07 ("tcp: Try to restore large SKBs while SACK processing")
Signed-off-by: Eric Dumazet 
Reported-by: Jonathan Looney 
Acked-by: Neal Cardwell 
Reviewed-by: Tyler Hicks 
Cc: Yuchung Cheng 
Cc: Bruce Curtis 
Cc: Jonathan Lemon 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Revert "Bluetooth: Align minimum encryption key size for LE and BR/EDR connections"

2019-06-15T09:54:59+00:00

This reverts commit 2fa7a155b25160696cd77cdd995536cf5e172e20 which is
commit d5bb334a8e171b262e48f378bd2096c0ea458265 upstream.

Lots of people have reported issues with this patch, and as there does
not seem to be a fix going into Linus's kernel tree any time soon,
revert the commit in the stable trees so as to get people's machines
working properly again.

Reported-by: Vasily Khoruzhick 
Reported-by: Hans de Goede 
Cc: Jeremy Cline 
Cc: Marcel Holtmann 
Cc: Johan Hedberg 
Signed-off-by: Greg Kroah-Hartman

ipv4: Define __ipv4_neigh_lookup_noref when CONFIG_INET is disabled

2019-06-11T10:21:51+00:00

commit 9b3040a6aafd7898ece7fc7efcbca71e42aa8069 upstream.

Define __ipv4_neigh_lookup_noref to return NULL when CONFIG_INET is disabled.

Fixes: 4b2a2bfeb3f0 ("neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit")
Reported-by: kbuild test robot 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Cc: Nobuhiro Iwamatsu 
Signed-off-by: Greg Kroah-Hartman

ipv6: fix the check before getting the cookie in rt6_get_cookie

2019-06-11T10:21:47+00:00

[ Upstream commit b7999b07726c16974ba9ca3bb9fe98ecbec5f81c ]

In Jianlin's testing, netperf was broken with 'Connection reset by peer',
as the cookie check failed in rt6_check() and ip6_dst_check() always
returned NULL.

It's caused by Commit 93531c674315 ("net/ipv6: separate handling of FIB
entries from dst based routes"), where the cookie can be got only when
'c1'(see below) for setting dst_cookie whereas rt6_check() is called
when !'c1' for checking dst_cookie, as we can see in ip6_dst_check().

Since in ip6_dst_check() both rt6_dst_from_check() (c1) and rt6_check()
(!c1) will check the 'from' cookie, this patch is to remove the c1 check
in rt6_get_cookie(), so that the dst_cookie can always be set properly.

c1:
  (rt->rt6i_flags & RTF_PCPU || unlikely(!list_empty(&rt->rt6i_uncached)))

Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes")
Reported-by: Jianlin Shi 
Signed-off-by: Xin Long 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

inet: switch IP ID generator to siphash

2019-06-09T07:18:10+00:00

[ Upstream commit df453700e8d81b1bdafdf684365ee2b9431fb702 ]

According to Amit Klein and Benny Pinkas, IP ID generation is too weak
and might be used by attackers.

Even with recent net_hash_mix() fix (netns: provide pure entropy for net_hash_mix())
having 64bit key and Jenkins hash is risky.

It is time to switch to siphash and its 128bit keys.

Signed-off-by: Eric Dumazet 
Reported-by: Amit Klein 
Reported-by: Benny Pinkas 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

nfc: nci: Potential off by one in ->pipes[] array

2019-05-16T17:42:32+00:00

[ Upstream commit 6491d698396fd5da4941980a35ca7c162a672016 ]

This is similar to commit e285d5bfb7e9 ("NFC: Fix the number of pipes")
where we changed NFC_HCI_MAX_PIPES from 127 to 128.

As the comment next to the define explains, the pipe identifier is 7
bits long.  The highest possible pipe is 127, but the number of possible
pipes is 128.  As the code is now, then there is potential for an
out of bounds array access:

    net/nfc/nci/hci.c:297 nci_hci_cmd_received() warn: array off by one?
    'ndev->hci_dev->pipes[pipe]' '0-127 == 127'

Fixes: 11f54f228643 ("NFC: nci: Add HCI over NCI protocol support")
Signed-off-by: Dan Carpenter 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

netfilter: ctnetlink: don't use conntrack/expect object addresses as id

2019-05-16T17:42:23+00:00

[ Upstream commit 3c79107631db1f7fd32cf3f7368e4672004a3010 ]

else, we leak the addresses to userspace via ctnetlink events
and dumps.

Compute an ID on demand based on the immutable parts of nf_conn struct.

Another advantage compared to using an address is that there is no
immediate re-use of the same ID in case the conntrack entry is freed and
reallocated again immediately.

Fixes: 3583240249ef ("[NETFILTER]: nf_conntrack_expect: kill unique ID")
Fixes: 7f85f914721f ("[NETFILTER]: nf_conntrack: kill unique ID")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

Bluetooth: Align minimum encryption key size for LE and BR/EDR connections

2019-05-10T15:53:15+00:00

commit d5bb334a8e171b262e48f378bd2096c0ea458265 upstream.

The minimum encryption key size for LE connections is 56 bits and to
align LE with BR/EDR, enforce 56 bits of minimum encryption key size for
BR/EDR connections as well.

Signed-off-by: Marcel Holtmann 
Signed-off-by: Johan Hedberg 
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

caif: reduce stack size with KASAN

2019-05-08T05:20:45+00:00

commit ce6289661b14a8b391d90db918c91b6d6da6540a upstream.

When CONFIG_KASAN is set, we can use relatively large amounts of kernel
stack space:

net/caif/cfctrl.c:555:1: warning: the frame size of 1600 bytes is larger than 1280 bytes [-Wframe-larger-than=]

This adds convenience wrappers around cfpkt_extr_head(), which is responsible
for most of the stack growth. With those wrapper functions, gcc apparently
starts reusing the stack slots for each instance, thus avoiding the
problem.

Signed-off-by: Arnd Bergmann 
Signed-off-by: David S. Miller 
Signed-off-by: Andrey Konovalov 
Signed-off-by: Greg Kroah-Hartman