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<title>lwn.git/net/decnet/af_decnet.c, branch v4.13-rc3</title>
<subtitle>Linux kernel documentation tree maintained by Jonathan Corbet</subtitle>
<id>http://mirrors.hust.edu.cn/git/lwn.git/atom?h=v4.13-rc3</id>
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<updated>2017-06-08T15:26:19+00:00</updated>
<entry>
<title>tcp: add TCPMemoryPressuresChrono counter</title>
<updated>2017-06-08T15:26:19+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2017-06-07T20:29:12+00:00</published>
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<id>urn:sha1:0604475119de5f80dc051a5db055c6a2a75bd542</id>
<content type='text'>
DRAM supply shortage and poor memory pressure tracking in TCP
stack makes any change in SO_SNDBUF/SO_RCVBUF (or equivalent autotuning
limits) and tcp_mem[] quite hazardous.

TCPMemoryPressures SNMP counter is an indication of tcp_mem sysctl
limits being hit, but only tracking number of transitions.

If TCP stack behavior under stress was perfect :
1) It would maintain memory usage close to the limit.
2) Memory pressure state would be entered for short times.

We certainly prefer 100 events lasting 10ms compared to one event
lasting 200 seconds.

This patch adds a new SNMP counter tracking cumulative duration of
memory pressure events, given in ms units.

$ cat /proc/sys/net/ipv4/tcp_mem
3088    4117    6176
$ grep TCP /proc/net/sockstat
TCP: inuse 180 orphan 0 tw 2 alloc 234 mem 4140
$ nstat -n ; sleep 10 ; nstat |grep Pressure
TcpExtTCPMemoryPressures        1700
TcpExtTCPMemoryPressuresChrono  5209

v2: Used EXPORT_SYMBOL_GPL() instead of EXPORT_SYMBOL() as David
instructed.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>format-security: move static strings to const</title>
<updated>2017-05-09T00:15:14+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2017-05-08T22:59:05+00:00</published>
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<id>urn:sha1:063246641d4a9e9de84a2466fbad50112faf88dc</id>
<content type='text'>
While examining output from trial builds with -Wformat-security enabled,
many strings were found that should be defined as "const", or as a char
array instead of char pointer.  This makes some static analysis easier,
by producing fewer false positives.

As these are all trivial changes, it seemed best to put them all in a
single patch rather than chopping them up per maintainer.

Link: http://lkml.kernel.org/r/20170405214711.GA5711@beast
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Jes Sorensen &lt;jes@trained-monkey.org&gt;	[runner.c]
Cc: Tony Lindgren &lt;tony@atomide.com&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: "Maciej W. Rozycki" &lt;macro@linux-mips.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: "Rafael J. Wysocki" &lt;rjw@rjwysocki.net&gt;
Cc: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Cc: Daniel Vetter &lt;daniel.vetter@intel.com&gt;
Cc: Jani Nikula &lt;jani.nikula@linux.intel.com&gt;
Cc: Sean Paul &lt;seanpaul@chromium.org&gt;
Cc: David Airlie &lt;airlied@linux.ie&gt;
Cc: Yisen Zhuang &lt;yisen.zhuang@huawei.com&gt;
Cc: Salil Mehta &lt;salil.mehta@huawei.com&gt;
Cc: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
Cc: Jiri Slaby &lt;jslaby@suse.com&gt;
Cc: Patrice Chotard &lt;patrice.chotard@st.com&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Paul Burton &lt;paul.burton@imgtec.com&gt;
Cc: Matt Redfearn &lt;matt.redfearn@imgtec.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Cc: Mugunthan V N &lt;mugunthanvnm@ti.com&gt;
Cc: Felipe Balbi &lt;felipe.balbi@linux.intel.com&gt;
Cc: Jarod Wilson &lt;jarod@redhat.com&gt;
Cc: Florian Westphal &lt;fw@strlen.de&gt;
Cc: Antonio Quartulli &lt;a@unstable.cc&gt;
Cc: Dmitry Torokhov &lt;dmitry.torokhov@gmail.com&gt;
Cc: Kejian Yan &lt;yankejian@huawei.com&gt;
Cc: Daode Huang &lt;huangdaode@hisilicon.com&gt;
Cc: Qianqian Xie &lt;xieqianqian@huawei.com&gt;
Cc: Philippe Reynes &lt;tremyfr@gmail.com&gt;
Cc: Colin Ian King &lt;colin.king@canonical.com&gt;
Cc: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Christian Gromm &lt;christian.gromm@microchip.com&gt;
Cc: Andrey Shvetsov &lt;andrey.shvetsov@k2l.de&gt;
Cc: Jason Litzinger &lt;jlitzingerdev@gmail.com&gt;
Cc: WANG Cong &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2017-03-15T18:59:10+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2017-03-15T18:59:10+00:00</published>
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<id>urn:sha1:101c431492d297dd0d111b461d8d324895676bee</id>
<content type='text'>
Conflicts:
	drivers/net/ethernet/broadcom/genet/bcmgenet.c
	net/core/sock.c

Conflicts were overlapping changes in bcmgenet and the
lockdep handling of sockets.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: Work around lockdep limitation in sockets that use sockets</title>
<updated>2017-03-10T02:23:27+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-03-09T08:09:05+00:00</published>
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<id>urn:sha1:cdfbabfb2f0ce983fdaa42f20e5f7842178fc01e</id>
<content type='text'>
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.

The theory lockdep comes up with is as follows:

 (1) If the pagefault handler decides it needs to read pages from AFS, it
     calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
     creating a call requires the socket lock:

	mmap_sem must be taken before sk_lock-AF_RXRPC

 (2) afs_open_socket() opens an AF_RXRPC socket and binds it.  rxrpc_bind()
     binds the underlying UDP socket whilst holding its socket lock.
     inet_bind() takes its own socket lock:

	sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET

 (3) Reading from a TCP socket into a userspace buffer might cause a fault
     and thus cause the kernel to take the mmap_sem, but the TCP socket is
     locked whilst doing this:

	sk_lock-AF_INET must be taken before mmap_sem

However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks.  The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace.  This is
a limitation in the design of lockdep.

Fix the general case by:

 (1) Double up all the locking keys used in sockets so that one set are
     used if the socket is created by userspace and the other set is used
     if the socket is created by the kernel.

 (2) Store the kern parameter passed to sk_alloc() in a variable in the
     sock struct (sk_kern_sock).  This informs sock_lock_init(),
     sock_init_data() and sk_clone_lock() as to the lock keys to be used.

     Note that the child created by sk_clone_lock() inherits the parent's
     kern setting.

 (3) Add a 'kern' parameter to -&gt;accept() that is analogous to the one
     passed in to -&gt;create() that distinguishes whether kernel_accept() or
     sys_accept4() was the caller and can be passed to sk_alloc().

     Note that a lot of accept functions merely dequeue an already
     allocated socket.  I haven't touched these as the new socket already
     exists before we get the parameter.

     Note also that there are a couple of places where I've made the accepted
     socket unconditionally kernel-based:

	irda_accept()
	rds_rcp_accept_one()
	tcp_accept_from_sock()

     because they follow a sock_create_kern() and accept off of that.

Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal.  I wonder if these should do that so
that they use the new set of lock keys.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>decnet: Use TCP nagle macro instead of literal number in decnet</title>
<updated>2017-03-07T22:07:55+00:00</updated>
<author>
<name>Gao Feng</name>
<email>fgao@ikuai8.com</email>
</author>
<published>2017-03-04T14:10:28+00:00</published>
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<id>urn:sha1:9c28286b1b4b9bce6e35dd4c8a1265f03802a89a</id>
<content type='text'>
Use existing TCP nagle macro TCP_NAGLE_OFF and TCP_NAGLE_CORK instead
of the literal number 1 and 2 in the current decnet codes.

Signed-off-by: Gao Feng &lt;fgao@ikuai8.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>sched/headers: Prepare for new header dependencies before moving code to &lt;linux/sched/signal.h&gt;</title>
<updated>2017-03-02T07:42:29+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-02-08T17:51:30+00:00</published>
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<id>urn:sha1:3f07c0144132e4f59d88055ac8ff3e691a5fa2b8</id>
<content type='text'>
We are going to split &lt;linux/sched/signal.h&gt; out of &lt;linux/sched.h&gt;, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder &lt;linux/sched/signal.h&gt; file that just
maps to &lt;linux/sched.h&gt; to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
</entry>
<entry>
<title>net: fix sleeping for sk_wait_event()</title>
<updated>2016-11-14T18:17:21+00:00</updated>
<author>
<name>WANG Cong</name>
<email>xiyou.wangcong@gmail.com</email>
</author>
<published>2016-11-11T18:20:50+00:00</published>
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<id>urn:sha1:d9dc8b0f8b4ec8cdc48ad5a20a3105387138be82</id>
<content type='text'>
Similar to commit 14135f30e33c ("inet: fix sleeping inside inet_wait_for_connect()"),
sk_wait_event() needs to fix too, because release_sock() is blocking,
it changes the process state back to running after sleep, which breaks
the previous prepare_to_wait().

Switch to the new wait API.

Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Signed-off-by: Cong Wang &lt;xiyou.wangcong@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: add validation for the socket syscall protocol argument</title>
<updated>2015-12-14T21:09:30+00:00</updated>
<author>
<name>Hannes Frederic Sowa</name>
<email>hannes@stressinduktion.org</email>
</author>
<published>2015-12-14T21:03:39+00:00</published>
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<id>urn:sha1:79462ad02e861803b3840cc782248c7359451cd9</id>
<content type='text'>
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 , &amp;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:  [&lt;ffffffff816db90e&gt;] ? inet_autobind+0x2e/0x70
kernel:  [&lt;ffffffff816db9a4&gt;] inet_dgram_connect+0x54/0x80
kernel:  [&lt;ffffffff81645069&gt;] SYSC_connect+0xd9/0x110
kernel:  [&lt;ffffffff810ac51b&gt;] ? ptrace_notify+0x5b/0x80
kernel:  [&lt;ffffffff810236d8&gt;] ? syscall_trace_enter_phase2+0x108/0x200
kernel:  [&lt;ffffffff81645e0e&gt;] SyS_connect+0xe/0x10
kernel:  [&lt;ffffffff81779515&gt;] tracesys_phase2+0x84/0x89

I found no particular commit which introduced this problem.

CVE: CVE-2015-8543
Cc: Cong Wang &lt;cwang@twopensource.com&gt;
Reported-by: 郭永刚 &lt;guoyonggang@360.cn&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: rename SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA</title>
<updated>2015-12-01T20:45:05+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2015-11-30T04:03:10+00:00</published>
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<id>urn:sha1:9cd3e072b0be17446e37d7414eac8a3499e0601e</id>
<content type='text'>
This patch is a cleanup to make following patch easier to
review.

Goal is to move SOCK_ASYNC_NOSPACE and SOCK_ASYNC_WAITDATA
from (struct socket)-&gt;flags to a (struct socket_wq)-&gt;flags
to benefit from RCU protection in sock_wake_async()

To ease backports, we rename both constants.

Two new helpers, sk_set_bit(int nr, struct sock *sk)
and sk_clear_bit(int net, struct sock *sk) are added so that
following patch can change their implementation.

Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: Pass kern from net_proto_family.create to sk_alloc</title>
<updated>2015-05-11T14:50:17+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2015-05-09T02:09:13+00:00</published>
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<id>urn:sha1:11aa9c28b4209242a9de0a661a7b3405adb568a0</id>
<content type='text'>
In preparation for changing how struct net is refcounted
on kernel sockets pass the knowledge that we are creating
a kernel socket from sock_create_kern through to sk_alloc.

Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
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