linux-stable.git/include/net/sock.h, branch v3.2.99

net: avoid sk_forward_alloc overflows

2017-03-16T02:18:53+00:00

[ Upstream commit 20c64d5cd5a2bdcdc8982a06cb05e5e1bd851a3d ]

A malicious TCP receiver, sending SACK, can force the sender to split
skbs in write queue and increase its memory usage.

Then, when socket is closed and its write queue purged, we might
overflow sk_forward_alloc (It becomes negative)

sk_mem_reclaim() does nothing in this case, and more than 2GB
are leaked from TCP perspective (tcp_memory_allocated is not changed)

Then warnings trigger from inet_sock_destruct() and
sk_stream_kill_queues() seeing a not zero sk_forward_alloc

All TCP stack can be stuck because TCP is under memory pressure.

A simple fix is to preemptively reclaim from sk_mem_uncharge().

This makes sure a socket wont have more than 2 MB forward allocated,
after burst and idle period.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: fix sk_mem_reclaim_partial()

2017-03-16T02:18:52+00:00

commit 1a24e04e4b50939daa3041682b38b82c896ca438 upstream.

sk_mem_reclaim_partial() goal is to ensure each socket has
one SK_MEM_QUANTUM forward allocation. This is needed both for
performance and better handling of memory pressure situations in
follow up patches.

SK_MEM_QUANTUM is currently a page, but might be reduced to 4096 bytes
as some arches have 64KB pages.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - Keep using atomic_long_sub() directly, not sk_memory_allocated_sub()
 - Adjust context]
Signed-off-by: Ben Hutchings

net/sock: Add sock_efree() function

2017-03-16T02:18:49+00:00

Extracted from commit 62bccb8cdb69 ("net-timestamp: Make the clone operation
stand-alone from phy timestamping").

Signed-off-by: Ben Hutchings

dccp: limit sk_filter trim to payload

2017-02-23T03:51:05+00:00

commit 4f0c40d94461cfd23893a17335b2ab78ecb333c8 upstream.

Dccp verifies packet integrity, including length, at initial rcv in
dccp_invalid_packet, later pulls headers in dccp_enqueue_skb.

A call to sk_filter in-between can cause __skb_pull to wrap skb->len.
skb_copy_datagram_msg interprets this as a negative value, so
(correctly) fails with EFAULT. The negative length is reported in
ioctl SIOCINQ or possibly in a DCCP_WARN in dccp_close.

Introduce an sk_receive_skb variant that caps how small a filter
program can trim packets, and call this in dccp with the header
length. Excessively trimmed packets are now processed normally and
queued for reception as 0B payloads.

Fixes: 7c657876b63c ("[DCCP]: Initial implementation")
Signed-off-by: Willem de Bruijn 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

net: Add __sock_queue_rcv_skb()

2017-02-23T03:51:05+00:00

Extraxcted from commit e6afc8ace6dd5cef5e812f26c72579da8806f5ac
"udp: remove headers from UDP packets before queueing".

Signed-off-by: Ben Hutchings

net: fix warnings in 'make htmldocs' by moving macro definition out of field declaration

2016-01-22T21:40:05+00:00

commit 7bbadd2d1009575dad675afc16650ebb5aa10612 upstream.

Docbook does not like the definition of macros inside a field declaration
and adds a warning. Move the definition out.

Fixes: 79462ad02e86180 ("net: add validation for the socket syscall protocol argument")
Reported-by: kbuild test robot 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: keep open-coding U8_MAX]
Signed-off-by: Ben Hutchings

net: add validation for the socket syscall protocol argument

2015-12-30T02:26:03+00:00

[ Upstream commit 79462ad02e861803b3840cc782248c7359451cd9 ]

郭永刚 reported that one could simply crash the kernel as root by
using a simple program:

	int socket_fd;
	struct sockaddr_in addr;
	addr.sin_port = 0;
	addr.sin_addr.s_addr = INADDR_ANY;
	addr.sin_family = 10;

	socket_fd = socket(10,3,0x40000000);
	connect(socket_fd , &addr,16);

AF_INET, AF_INET6 sockets actually only support 8-bit protocol
identifiers. inet_sock's skc_protocol field thus is sized accordingly,
thus larger protocol identifiers simply cut off the higher bits and
store a zero in the protocol fields.

This could lead to e.g. NULL function pointer because as a result of
the cut off inet_num is zero and we call down to inet_autobind, which
is NULL for raw sockets.

kernel: Call Trace:
kernel:  [] ? inet_autobind+0x2e/0x70
kernel:  [] inet_dgram_connect+0x54/0x80
kernel:  [] SYSC_connect+0xd9/0x110
kernel:  [] ? ptrace_notify+0x5b/0x80
kernel:  [] ? syscall_trace_enter_phase2+0x108/0x200
kernel:  [] SyS_connect+0xe/0x10
kernel:  [] tracesys_phase2+0x84/0x89

I found no particular commit which introduced this problem.

CVE: CVE-2015-8543
Cc: Cong Wang 
Reported-by: 郭永刚 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: open-code U8_MAX]
Signed-off-by: Ben Hutchings

sctp: update the netstamp_needed counter when copying sockets

2015-12-30T02:26:03+00:00

[ Upstream commit 01ce63c90170283a9855d1db4fe81934dddce648 ]

Dmitry Vyukov reported that SCTP was triggering a WARN on socket destroy
related to disabling sock timestamp.

When SCTP accepts an association or peel one off, it copies sock flags
but forgot to call net_enable_timestamp() if a packet timestamping flag
was copied, leading to extra calls to net_disable_timestamp() whenever
such clones were closed.

The fix is to call net_enable_timestamp() whenever we copy a sock with
that flag on, like tcp does.

Reported-by: Dmitry Vyukov 
Signed-off-by: Marcelo Ricardo Leitner 
Acked-by: Vlad Yasevich 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: SK_FLAGS_TIMESTAMP is newly defined]
Signed-off-by: Ben Hutchings

Revert "tcp: Apply device TSO segment limit earlier"

2015-02-20T00:49:33+00:00

This reverts commit 9f871e883277cc22c6217db806376dce52401a31, which
was commit 1485348d2424e1131ea42efc033cbd9366462b01 upstream.

It can cause connections to stall when a PMTU event occurs.  This was
fixed by commit 843925f33fcc ("tcp: Do not apply TSO segment limit to
non-TSO packets") upstream, but that depends on other changes to TSO.

The original issue this fixed was a performance regression for the sfc
driver in extreme cases of TSO (skb with > 100 segments).  This is not
really very important and it seems best to revert it rather than try
to fix it up.

Signed-off-by: Ben Hutchings 
Cc: Herbert Xu 
Cc: netdev@vger.kernel.org
Cc: linux-net-drivers@solarflare.com

ipv6: do not clear pinet6 field

2013-05-30T13:35:14+00:00

[ Upstream commit f77d602124d865c38705df7fa25c03de9c284ad2 ]

We have seen multiple NULL dereferences in __inet6_lookup_established()

After analysis, I found that inet6_sk() could be NULL while the
check for sk_family == AF_INET6 was true.

Bug was added in linux-2.6.29 when RCU lookups were introduced in UDP
and TCP stacks.

Once an IPv6 socket, using SLAB_DESTROY_BY_RCU is inserted in a hash
table, we no longer can clear pinet6 field.

This patch extends logic used in commit fcbdf09d9652c891
("net: fix nulls list corruptions in sk_prot_alloc")

TCP/UDP/UDPLite IPv6 protocols provide their own .clear_sk() method
to make sure we do not clear pinet6 field.

At socket clone phase, we do not really care, as cloning the parent (non
NULL) pinet6 is not adding a fatal race.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings