linux-toradex.git/net/core, branch v4.7

dccp: limit sk_filter trim to payload

2016-07-13T18:53:41+00:00

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

rose: limit sk_filter trim to payload

2016-07-13T18:53:40+00:00

Sockets can have a filter program attached that drops or trims
incoming packets based on the filter program return value.

Rose requires data packets to have at least ROSE_MIN_LEN bytes. It
verifies this on arrival in rose_route_frame and unconditionally pulls
the bytes in rose_recvmsg. The filter can trim packets to below this
value in-between, causing pull to fail, leaving the partial header at
the time of skb_copy_datagram_msg.

Place a lower bound on the size to which sk_filter may trim packets
by introducing sk_filter_trim_cap and call this for rose packets.

Signed-off-by: Willem de Bruijn 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

sock: ignore SCM_RIGHTS and SCM_CREDENTIALS in __sock_cmsg_send

2016-07-11T21:32:44+00:00

Sergei Trofimovich reported that pulse audio sends SCM_CREDENTIALS
as a control message to TCP. Since __sock_cmsg_send does not
support SCM_RIGHTS and SCM_CREDENTIALS, it returns an error and
hence breaks pulse audio over TCP.

SCM_RIGHTS and SCM_CREDENTIALS are sent on the SOL_SOCKET layer
but they semantically belong to SOL_UNIX. Since all
cmsg-processing functions including sock_cmsg_send ignore control
messages of other layers, it is best to ignore SCM_RIGHTS
and SCM_CREDENTIALS for consistency (and also for fixing pulse
audio over TCP).

Fixes: c14ac9451c34 ("sock: enable timestamping using control messages")
Signed-off-by: Soheil Hassas Yeganeh 
Reported-by: Sergei Trofimovich 
Tested-by: Sergei Trofimovich 
Cc: Eric Dumazet 
Cc: Willem de Bruijn 
Signed-off-by: David S. Miller

net_sched: fix mirrored packets checksum

2016-07-01T20:19:34+00:00

Similar to commit 9b368814b336 ("net: fix bridge multicast packet checksum validation")
we need to fixup the checksum for CHECKSUM_COMPLETE when
pushing skb on RX path. Otherwise we get similar splats.

Cc: Jamal Hadi Salim 
Cc: Tom Herbert 
Signed-off-by: Cong Wang 
Acked-by: Jamal Hadi Salim 
Signed-off-by: David S. Miller

packet: Use symmetric hash for PACKET_FANOUT_HASH.

2016-07-01T20:07:50+00:00

People who use PACKET_FANOUT_HASH want a symmetric hash, meaning that
they want packets going in both directions on a flow to hash to the
same bucket.

The core kernel SKB hash became non-symmetric when the ipv6 flow label
and other entities were incorporated into the standard flow hash order
to increase entropy.

But there are no users of PACKET_FANOUT_HASH who want an assymetric
hash, they all want a symmetric one.

Therefore, use the flow dissector to compute a flat symmetric hash
over only the protocol, addresses and ports.  This hash does not get
installed into and override the normal skb hash, so this change has
no effect whatsoever on the rest of the stack.

Reported-by: Eric Leblond 
Tested-by: Eric Leblond 
Signed-off-by: David S. Miller

neigh: Explicitly declare RCU-bh read side critical section in neigh_xmit()

2016-06-29T11:58:28+00:00

neigh_xmit() expects to be called inside an RCU-bh read side critical
section, and while one of its two current callers gets this right, the
other one doesn't.

More specifically, neigh_xmit() has two callers, mpls_forward() and
mpls_output(), and while both callers call neigh_xmit() under
rcu_read_lock(), this provides sufficient protection for neigh_xmit()
only in the case of mpls_forward(), as that is always called from
softirq context and therefore doesn't need explicit BH protection,
while mpls_output() can be called from process context with softirqs
enabled.

When mpls_output() is called from process context, with softirqs
enabled, we can be preempted by a softirq at any time, and RCU-bh
considers the completion of a softirq as signaling the end of any
pending read-side critical sections, so if we do get a softirq
while we are in the part of neigh_xmit() that expects to be run inside
an RCU-bh read side critical section, we can end up with an unexpected
RCU grace period running right in the middle of that critical section,
making things go boom.

This patch fixes this impedance mismatch in the callee, by making
neigh_xmit() always take rcu_read_{,un}lock_bh() around the code that
expects to be treated as an RCU-bh read side critical section, as this
seems a safer option than fixing it in the callers.

Fixes: 4fd3d7d9e868f ("neigh: Add helper function neigh_xmit")
Signed-off-by: David Barroso 
Signed-off-by: Lennert Buytenhek 
Acked-by: David Ahern 
Acked-by: Robert Shearman 
Signed-off-by: David S. Miller

bpf: fix matching of data/data_end in verifier

2016-06-16T06:37:54+00:00

The ctx structure passed into bpf programs is different depending on bpf
program type. The verifier incorrectly marked ctx->data and ctx->data_end
access based on ctx offset only. That caused loads in tracing programs
int bpf_prog(struct pt_regs *ctx) { .. ctx->ax .. }
to be incorrectly marked as PTR_TO_PACKET which later caused verifier
to reject the program that was actually valid in tracing context.
Fix this by doing program type specific matching of ctx offsets.

Fixes: 969bf05eb3ce ("bpf: direct packet access")
Reported-by: Sasha Goldshtein 
Signed-off-by: Alexei Starovoitov 
Acked-by: Daniel Borkmann 
Signed-off-by: David S. Miller

net_sched: add missing paddattr description

2016-06-08T18:17:39+00:00

"make htmldocs" complains otherwise:

.//net/core/gen_stats.c:65: warning: No description found for parameter 'padattr'
.//net/core/gen_stats.c:101: warning: No description found for parameter 'padattr'

Fixes: 9854518ea04d ("sched: align nlattr properly when needed")
Signed-off-by: Eric Dumazet 
Reported-by: kbuild test robot 
Acked-by: Nicolas Dichtel 
Signed-off-by: David S. Miller

net-sysfs: fix missing

2016-06-08T07:37:58+00:00

The of_find_net_device_by_node() function is defined in
 but not included in the .c file that
implements it. Fix the following warning by including the
header:

net/core/net-sysfs.c:1494:19: warning: symbol 'of_find_net_device_by_node' was not declared. Should it be static?

Signed-off-by: Ben Dooks 
Signed-off-by: David S. Miller

net: pktgen: Call destroy_hrtimer_on_stack()

2016-05-31T18:44:08+00:00

If CONFIG_DEBUG_OBJECTS_TIMERS=y, hrtimer_init_on_stack() requires
a matching call to destroy_hrtimer_on_stack() to clean up timer
debug objects.

Signed-off-by: Guenter Roeck 
Signed-off-by: David S. Miller