linux-stable.git/net/core, branch v3.2.72

fib_rules: fix fib rule dumps across multiple skbs

2015-10-13T02:46:12+00:00

[ Upstream commit 41fc014332d91ee90c32840bf161f9685b7fbf2b ]

dump_rules returns skb length and not error.
But when family == AF_UNSPEC, the caller of dump_rules
assumes that it returns an error. Hence, when family == AF_UNSPEC,
we continue trying to dump on -EMSGSIZE errors resulting in
incorrect dump idx carried between skbs belonging to the same dump.
This results in fib rule dump always only dumping rules that fit
into the first skb.

This patch fixes dump_rules to return error so that we exit correctly
and idx is correctly maintained between skbs that are part of the
same dump.

Signed-off-by: Wilson Kok 
Signed-off-by: Roopa Prabhu 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - s/portid/pid/
 - Check whether fib_nl_fill_rule() returns < 0, as it may return > 0 on
   success (thanks to Roland Dreier)]
Signed-off-by: Ben Hutchings 
Cc: Roland Dreier

net: Fix skb csum races when peeking

2015-10-13T02:46:12+00:00

[ Upstream commit 89c22d8c3b278212eef6a8cc66b570bc840a6f5a ]

When we calculate the checksum on the recv path, we store the
result in the skb as an optimisation in case we need the checksum
again down the line.

This is in fact bogus for the MSG_PEEK case as this is done without
any locking.  So multiple threads can peek and then store the result
to the same skb, potentially resulting in bogus skb states.

This patch fixes this by only storing the result if the skb is not
shared.  This preserves the optimisations for the few cases where
it can be done safely due to locking or other reasons, e.g., SIOCINQ.

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

net: pktgen: fix race between pktgen_thread_worker() and kthread_stop()

2015-10-13T02:46:12+00:00

[ Upstream commit fecdf8be2d91e04b0a9a4f79ff06499a36f5d14f ]

pktgen_thread_worker() is obviously racy, kthread_stop() can come
between the kthread_should_stop() check and set_current_state().

Signed-off-by: Oleg Nesterov 
Reported-by: Jan Stancek 
Reported-by: Marcelo Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: Fix skb_set_peeked use-after-free bug

2015-10-13T02:46:02+00:00

commit a0a2a6602496a45ae838a96db8b8173794b5d398 upstream.

The commit 738ac1ebb96d02e0d23bc320302a6ea94c612dec ("net: Clone
skb before setting peeked flag") introduced a use-after-free bug
in skb_recv_datagram.  This is because skb_set_peeked may create
a new skb and free the existing one.  As it stands the caller will
continue to use the old freed skb.

This patch fixes it by making skb_set_peeked return the new skb
(or the old one if unchanged).

Fixes: 738ac1ebb96d ("net: Clone skb before setting peeked flag")
Reported-by: Brenden Blanco 
Signed-off-by: Herbert Xu 
Tested-by: Brenden Blanco 
Reviewed-by: Konstantin Khlebnikov 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

net: Clone skb before setting peeked flag

2015-10-13T02:46:02+00:00

commit 738ac1ebb96d02e0d23bc320302a6ea94c612dec upstream.

Shared skbs must not be modified and this is crucial for broadcast
and/or multicast paths where we use it as an optimisation to avoid
unnecessary cloning.

The function skb_recv_datagram breaks this rule by setting peeked
without cloning the skb first.  This causes funky races which leads
to double-free.

This patch fixes this by cloning the skb and replacing the skb
in the list when setting skb->peeked.

Fixes: a59322be07c9 ("[UDP]: Only increment counter on first peek/recv")
Reported-by: Konstantin Khlebnikov 
Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

datagram: Factor out sk queue referencing

2015-08-12T14:33:22+00:00

commit 4934b0329f7150dcb5f90506860e2db32274c755 upstream.

This makes lines shorter and simplifies further patching.

Signed-off-by: Pavel Emelyanov 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller 
[bwh: Prerequisite of "net: Clone skb before setting peeked flag"]
Signed-off-by: Ben Hutchings

net: call rcu_read_lock early in process_backlog

2015-08-12T14:33:21+00:00

commit 2c17d27c36dcce2b6bf689f41a46b9e909877c21 upstream.

Incoming packet should be either in backlog queue or
in RCU read-side section. Otherwise, the final sequence of
flush_backlog() and synchronize_net() may miss packets
that can run without device reference:

CPU 1                  CPU 2
                       skb->dev: no reference
                       process_backlog:__skb_dequeue
                       process_backlog:local_irq_enable

on_each_cpu for
flush_backlog =>       IPI(hardirq): flush_backlog
                       - packet not found in backlog

                       CPU delayed ...
synchronize_net
- no ongoing RCU
read-side sections

netdev_run_todo,
rcu_barrier: no
ongoing callbacks
                       __netif_receive_skb_core:rcu_read_lock
                       - too late
free dev
                       process packet for freed dev

Fixes: 6e583ce5242f ("net: eliminate refcounting in backlog queue")
Cc: Eric W. Biederman 
Cc: Stephen Hemminger 
Signed-off-by: Julian Anastasov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - Adjust context
 - No need to rename the label in __netif_receive_skb()]
Signed-off-by: Ben Hutchings

net: do not process device backlog during unregistration

2015-08-12T14:33:20+00:00

commit e9e4dd3267d0c5234c5c0f47440456b10875dec9 upstream.

commit 381c759d9916 ("ipv4: Avoid crashing in ip_error")
fixes a problem where processed packet comes from device
with destroyed inetdev (dev->ip_ptr). This is not expected
because inetdev_destroy is called in NETDEV_UNREGISTER
phase and packets should not be processed after
dev_close_many() and synchronize_net(). Above fix is still
required because inetdev_destroy can be called for other
reasons. But it shows the real problem: backlog can keep
packets for long time and they do not hold reference to
device. Such packets are then delivered to upper levels
at the same time when device is unregistered.
Calling flush_backlog after NETDEV_UNREGISTER_FINAL still
accounts all packets from backlog but before that some packets
continue to be delivered to upper levels long after the
synchronize_net call which is supposed to wait the last
ones. Also, as Eric pointed out, processed packets, mostly
from other devices, can continue to add new packets to backlog.

Fix the problem by moving flush_backlog early, after the
device driver is stopped and before the synchronize_net() call.
Then use netif_running check to make sure we do not add more
packets to backlog. We have to do it in enqueue_to_backlog
context when the local IRQ is disabled. As result, after the
flush_backlog and synchronize_net sequence all packets
should be accounted.

Thanks to Eric W. Biederman for the test script and his
valuable feedback!

Reported-by: Vittorio Gambaletta 
Fixes: 6e583ce5242f ("net: eliminate refcounting in backlog queue")
Cc: Eric W. Biederman 
Cc: Stephen Hemminger 
Signed-off-by: Julian Anastasov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings

rtnetlink: verify IFLA_VF_INFO attributes before passing them to driver

2015-08-12T14:33:20+00:00

commit 4f7d2cdfdde71ffe962399b7020c674050329423 upstream.

Jason Gunthorpe reported that since commit c02db8c6290b ("rtnetlink: make
SR-IOV VF interface symmetric"), we don't verify IFLA_VF_INFO attributes
anymore with respect to their policy, that is, ifla_vfinfo_policy[].

Before, they were part of ifla_policy[], but they have been nested since
placed under IFLA_VFINFO_LIST, that contains the attribute IFLA_VF_INFO,
which is another nested attribute for the actual VF attributes such as
IFLA_VF_MAC, IFLA_VF_VLAN, etc.

Despite the policy being split out from ifla_policy[] in this commit,
it's never applied anywhere. nla_for_each_nested() only does basic nla_ok()
testing for struct nlattr, but it doesn't know about the data context and
their requirements.

Fix, on top of Jason's initial work, does 1) parsing of the attributes
with the right policy, and 2) using the resulting parsed attribute table
from 1) instead of the nla_for_each_nested() loop (just like we used to
do when still part of ifla_policy[]).

Reference: http://thread.gmane.org/gmane.linux.network/368913
Fixes: c02db8c6290b ("rtnetlink: make SR-IOV VF interface symmetric")
Reported-by: Jason Gunthorpe 
Cc: Chris Wright 
Cc: Sucheta Chakraborty 
Cc: Greg Rose 
Cc: Jeff Kirsher 
Cc: Rony Efraim 
Cc: Vlad Zolotarov 
Cc: Nicolas Dichtel 
Cc: Thomas Graf 
Signed-off-by: Jason Gunthorpe 
Signed-off-by: Daniel Borkmann 
Acked-by: Vlad Zolotarov 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - Drop unsupported attributes
 - Use ndo_set_vf_tx_rate operation, not ndo_set_vf_rate]
Signed-off-by: Ben Hutchings

pktgen: adjust spacing in proc file interface output

2015-08-12T14:33:12+00:00

commit d079abd181950a44cdf31daafd1662388a6c4d2e upstream.

Too many spaces were introduced in commit 63adc6fb8ac0 ("pktgen: cleanup
checkpatch warnings"), thus misaligning "src_min:" to other columns.

Fixes: 63adc6fb8ac0 ("pktgen: cleanup checkpatch warnings")
Signed-off-by: Jesper Dangaard Brouer 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings