We found that a TCP Fast Open passive connection was vulnerable
to reorders, as the exchange might look like
[1] C -> S S <FO ...> <request>
[2] S -> C S. ack request <options>
[3] S -> C . <answer>
packets [2] and [3] can be generated at almost the same time.
If C receives the 3rd packet before the 2nd, it will drop it as
the socket is in SYN_SENT state and expects a SYNACK.
S will have to retransmit the answer.
Current OOO avoidance in linux is defeated because SYNACK
packets are attached to the LISTEN socket, while DATA packets
are attached to the children. They might be sent by different cpus,
and different TX queues might be selected.
It turns out that for TFO, we created a child, which is a
full blown socket in TCP_SYN_RECV state, and we simply can attach
the SYNACK packet to this socket.
This means that at the time tcp_sendmsg() pushes DATA packet,
skb->ooo_okay will be set iff the SYNACK packet had been sent
and TX completed.
This removes the reorder source at the host level.
We also removed the export of tcp_try_fastopen(), as it is no
longer called from IPv6.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow bridge forward delay to be configured when Spanning Tree is enabled.
Signed-off-by: Ian Wilson <iwilson@brocade.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
For metadata based vxlan interface, open both IPv4 and IPv6 socket. This is
much more user friendly: it's not necessary to create two vxlan interfaces
and pay attention to using the right one in routing rules.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
net/ipv4/arp.c
The net/ipv4/arp.c conflict was one commit adding a new
local variable while another commit was deleting one.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) When we run a tap on netlink sockets, we have to copy mmap'd SKBs
instead of cloning them. From Daniel Borkmann.
2) When converting classical BPF into eBPF, fix the setting of the
source reg to BPF_REG_X. From Tycho Andersen.
3) Fix igmpv3/mldv2 report parsing in the bridge multicast code, from
Linus Lussing.
4) Fix dst refcounting for ipv6 tunnels, from Martin KaFai Lau.
5) Set NLM_F_REPLACE flag properly when replacing ipv6 routes, from
Roopa Prabhu.
6) Add some new cxgb4 PCI device IDs, from Hariprasad Shenai.
7) Fix headroom tests and SKB leaks in ipv6 fragmentation code, from
Florian Westphal.
8) Check DMA mapping errors in bna driver, from Ivan Vecera.
9) Several 8139cp bug fixes (dev_kfree_skb_any in interrupt context,
misclearing of interrupt status in TX timeout handler, etc.) from
David Woodhouse.
10) In tipc, reset SKB header pointer after skb_linearize(), from Erik
Hugne.
11) Fix autobind races et al. in netlink code, from Herbert Xu with
help from Tejun Heo and others.
12) Missing SET_NETDEV_DEV in sunvnet driver, from Sowmini Varadhan.
13) Fix various races in timewait timer and reqsk_queue_hadh_req, from
Eric Dumazet.
14) Fix array overruns in mac80211, from Johannes Berg and Dan
Carpenter.
15) Fix data race in rhashtable_rehash_one(), from Dmitriy Vyukov.
16) Fix race between poll_one_napi and napi_disable, from Neil Horman.
17) Fix byte order in geneve tunnel port config, from John W Linville.
18) Fix handling of ARP replies over lightweight tunnels, from Jiri
Benc.
19) We can loop when fib rule dumps cross multiple SKBs, fix from Wilson
Kok and Roopa Prabhu.
20) Several reference count handling bug fixes in the PHY/MDIO layer
from Russel King.
21) Fix lockdep splat in ppp_dev_uninit(), from Guillaume Nault.
22) Fix crash in icmp_route_lookup(), from David Ahern.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (116 commits)
net: Fix panic in icmp_route_lookup
net: update docbook comment for __mdiobus_register()
ppp: fix lockdep splat in ppp_dev_uninit()
net: via/Kconfig: GENERIC_PCI_IOMAP required if PCI not selected
phy: marvell: add link partner advertised modes
net: fix net_device refcounting
phy: add phy_device_remove()
phy: fixed-phy: properly validate phy in fixed_phy_update_state()
net: fix phy refcounting in a bunch of drivers
of_mdio: fix MDIO phy device refcounting
phy: add proper phy struct device refcounting
phy: fix mdiobus module safety
net: dsa: fix of_mdio_find_bus() device refcount leak
phy: fix of_mdio_find_bus() device refcount leak
ip6_tunnel: Reduce log level in ip6_tnl_err() to debug
ip6_gre: Reduce log level in ip6gre_err() to debug
fib_rules: fix fib rule dumps across multiple skbs
bnx2x: byte swap rss_key to comply to Toeplitz specs
net: revert "net_sched: move tp->root allocation into fw_init()"
lwtunnel: remove source and destination UDP port config option
...
SYNACK packets are sent on behalf on unlocked listeners
or fastopen sockets. Mark socket as const to catch future changes
that might break the assumption.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is done to make sure we do not change listener socket
while sending SYNACK packets while socket lock is not held.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Like tcp_make_synack() the only time we might change the socket is
when calling sock_wmalloc(), which is using atomic operation to
update sk->sk_wmem_alloc
Also use MAX_DCCP_HEADER as both IPv4/IPv6 use this value for max_header.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This documents fact that listener lock might not be held
at the time SYNACK are sent.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is to document that socket lock might not be held at this point.
skb_set_owner_w() and ipv6_local_error() are using proper atomic ops
or spinlocks, so we promote the socket to non const when calling them.
netfilter hooks should never assume socket lock is held,
we also promote the socket to non const.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
listener socket is not locked when tcp_make_synack() is called.
We better make sure no field is written.
There is one exception : Since SYNACK packets are attached to the listener
at this moment (or SYN_RECV child in case of Fast Open),
sock_wmalloc() needs to update sk->sk_wmem_alloc, but this is done using
atomic operations so this is safe.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SYNACK packets might be sent without holding socket lock.
For DCTCP/ECN sake, we should call INET_ECN_xmit() while
socket lock is owned, and only when we init/change congestion control.
This also fixies a bug if congestion module is changed from
dctcp to another one on a listener : we now clear ECN bits
properly.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This function is used to build and send SYNACK packets,
possibly on behalf of unlocked listener socket.
Make sure we did not miss a write by making this socket const.
We no longer can use ip_select_ident() and have to either
set iph->id to 0 or directly call __ip_select_ident()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When TCP new listener is done, these functions will be called
without socket lock being held. Make sure they don't change
anything.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
socket is not modified, make it const so that callers can
do the same if they need.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ip6_dst_lookup_flow() and ip6_dst_lookup_tail() do not touch
socket, lets add a const qualifier.
This will permit the same change in inet6_csk_route_req()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is used by TCP listener core, and listener socket shall
not be modified by inet_csk_route_req().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Very soon, TCP stack might call inet_csk_route_req(), which
calls inet_csk_route_req() with an unlocked listener socket,
so we need to make sure ip_route_output_flow() is not trying to
change any field from its socket argument.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Soon, listener socket wont be locked when tcp_openreq_init_rwin()
is called. We need to read socket fields once, as their value
could change under us.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Soon, listener socket spinlock will no longer be held,
add const arguments to tcp_v[46]_init_req() to make clear these
functions can not mess socket fields.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The __netdev_find_adj() helper does not use its first argument, only the
device to find and list to walk through.
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
When creating a IP encapsulated tunnel the necessary l2tp module
should be loaded. It already works for UDP encapsulation, it just
doesn't work for direct IP encap.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It should not be necessary to do explicit module loading when
configuring L2TP. Modules should be loaded as needed instead
(as is done already with netlink and other tunnel types).
This patch adds a new module alias type and code to load
the sub module on demand.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Provide a device_type information for slave network devices created by
DSA, this is useful for user-space application to easily locate/search
for devices of a specific kind.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Highlights include:
Stable patches:
- fix v4.2 SEEK on files over 2 gigs
- Fix a layout segment reference leak when pNFS I/O falls back to inband I/O.
- Fix recovery of recalled read delegations
Bugfixes:
- Fix a case where NFSv4 fails to send CLOSE after a server reboot
- Fix sunrpc to wait for connections to complete before retrying
- Fix sunrpc races between transport connect/disconnect and shutdown
- Fix an infinite loop when layoutget fail with BAD_STATEID
- nfs/filelayout: Fix NULL reference caused by double freeing of fh_array
- Fix a bogus WARN_ON_ONCE() in O_DIRECT when layout commit_through_mds is set
- Fix layoutreturn/close ordering issues.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=GdeV
-----END PGP SIGNATURE-----
Merge tag 'nfs-for-4.3-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:
Stable patches:
- fix v4.2 SEEK on files over 2 gigs
- Fix a layout segment reference leak when pNFS I/O falls back to inband I/O.
- Fix recovery of recalled read delegations
Bugfixes:
- Fix a case where NFSv4 fails to send CLOSE after a server reboot
- Fix sunrpc to wait for connections to complete before retrying
- Fix sunrpc races between transport connect/disconnect and shutdown
- Fix an infinite loop when layoutget fail with BAD_STATEID
- nfs/filelayout: Fix NULL reference caused by double freeing of fh_array
- Fix a bogus WARN_ON_ONCE() in O_DIRECT when layout commit_through_mds is set
- Fix layoutreturn/close ordering issues"
* tag 'nfs-for-4.3-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFS41: make close wait for layoutreturn
NFS: Skip checking ds_cinfo.buckets when lseg's commit_through_mds is set
NFSv4.x/pnfs: Don't try to recover stateids twice in layoutget
NFSv4: Recovery of recalled read delegations is broken
NFS: Fix an infinite loop when layoutget fail with BAD_STATEID
NFS: Do cleanup before resetting pageio read/write to mds
SUNRPC: xs_sock_mark_closed() does not need to trigger socket autoclose
SUNRPC: Lock the transport layer on shutdown
nfs/filelayout: Fix NULL reference caused by double freeing of fh_array
SUNRPC: Ensure that we wait for connections to complete before retrying
SUNRPC: drop null test before destroy functions
nfs: fix v4.2 SEEK on files over 2 gigs
SUNRPC: Fix races between socket connection and destroy code
nfs: fix pg_test page count calculation
Failing to send a CLOSE if file is opened WRONLY and server reboots on a 4.x mount
of_find_net_device_by_node() uses class_find_device() internally to
lookup the corresponding network device. class_find_device() returns
a reference to the embedded struct device, with its refcount
incremented.
Add a comment to the definition in net/core/net-sysfs.c indicating the
need to drop this refcount, and fix the DSA code to drop this refcount
when the OF-generated platform data is cleaned up and freed. Also
arrange for the ref to be dropped when handling errors.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Current users of of_mdio_find_bus() leak a struct device refcount, as
they fail to clean up the reference obtained inside class_find_device().
Fix the DSA code to properly refcount the returned MDIO bus by:
1. taking a reference on the struct device whenever we assign it to
pd->chip[x].host_dev.
2. dropping the reference when we overwrite the existing reference.
3. dropping the reference when we free the data structure.
4. dropping the initial reference we obtained after setting up the
platform data structure, or on failure.
In step 2 above, where we obtain a new MDIO bus, there is no need to
take a reference on it as we would only have to drop it immediately
after assignment again, iow:
put_device(cd->host_dev); /* drop original assignment ref */
cd->host_dev = get_device(&mdio_bus_switch->dev); /* get our ref */
put_device(&mdio_bus_switch->dev); /* drop of_mdio_find_bus ref */
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now, since we have only 2 values for transaction phase, just use bool.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The enum is going to disappear, use the helpers instead.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
No longer used by drivers, as transaction queue with item destructors
takes care of abort phase internally in switchdev code. So kill it.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Before it disappears completely, move transaction phase enum under
transaction structure and make attr/obj structures a bit cleaner.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now, the memory allocation in prepare/commit state is done separatelly
in each driver (rocker). Introduce the similar mechanism in generic
switchdev code, in form of queue. That can be used not only for memory
allocations, but also for different items. Abort item destruction
is handled as well.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is temporary, name "trans" will be used for something else and
"trans_ph" will eventually disappear.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently error log messages in ip6_tnl_err are printed at 'warn'
level. This is different to other tunnel types which don't print
any messages. These log messages don't provide any information that
couldn't be deduced with networking tools. Also it can be annoying
to have one end of the tunnel go down and have the logs fill with
pointless messages such as "Path to destination invalid or inactive!".
This patch reduces the log level of these messages to 'dbg' level to
bring the visible behaviour into line with other tunnel types.
Signed-off-by: Matt Bennett <matt.bennett@alliedtelesis.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
* VHT MCS mask array overrun, reported by Dan Carpenter
* reset CQM history to always get a notification, from Sara Sharon
-----BEGIN PGP SIGNATURE-----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=4Ui5
-----END PGP SIGNATURE-----
Merge tag 'mac80211-for-davem-2015-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211
Johannes Berg says:
====================
Just two small fixes:
* VHT MCS mask array overrun, reported by Dan Carpenter
* reset CQM history to always get a notification, from Sara Sharon
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently error log messages in ip6gre_err are printed at 'warn'
level. This is different to most other tunnel types which don't
print any messages. These log messages don't provide any information
that couldn't be deduced with networking tools. Also it can be annoying
to have one end of the tunnel go down and have the logs fill with
pointless messages such as "Path to destination invalid or inactive!".
This patch reduces the log level of these messages to 'dbg' level to
bring the visible behaviour into line with other tunnel types.
Signed-off-by: Matt Bennett <matt.bennett@alliedtelesis.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <wkok@cumulusnetworks.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Neal suggested to move sk_txhash init into tcp_create_openreq_child(),
called both from IPv4 and IPv6.
This opportunity was missed in commit 58d607d3e5 ("tcp: provide
skb->hash to synack packets")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fw filter uses tp->root==NULL to check if it is the old method,
so it doesn't need allocation at all in this case. This patch
reverts the offending commit and adds some comments for old
method to make it obvious.
Fixes: 33f8b9ecdb ("net_sched: move tp->root allocation into fw_init()")
Reported-by: Akshat Kakkar <akshat.1984@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The UDP tunnel config is asymmetric wrt. to the ports used. The source and
destination ports from one direction of the tunnel are not related to the
ports of the other direction. We need to be able to respond to ARP requests
using the correct ports without involving routing.
As the consequence, UDP ports need to be fixed property of the tunnel
interface and cannot be set per route. Remove the ability to set ports per
route. This is still okay to do, as no kernel has been released with these
attributes yet.
Note that the ability to specify source and destination ports is preserved
for other users of the lwtunnel API which don't use routes for tunnel key
specification (like openvswitch).
If in the future we rework ARP handling to allow port specification, the
attributes can be added back.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
When using ip lwtunnels, the additional data for xmit (basically, the actual
tunnel to use) are carried in ip_tunnel_info either in dst->lwtstate or in
metadata dst. When replying to ARP requests, we need to send the reply to
the same tunnel the request came from. This means we need to construct
proper metadata dst for ARP replies.
We could perform another route lookup to get a dst entry with the correct
lwtstate. However, this won't always ensure that the outgoing tunnel is the
same as the incoming one, and it won't work anyway for IPv4 duplicate
address detection.
The only thing to do is to "reverse" the ip_tunnel_info.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 12fd84f438 ("ipv6: Remove unused neigh argument for
icmp6_dst_alloc() and its callers."), the neigh parameter of ndisc_send_na
and ndisc_send_ns is unused.
CC: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The genl_notify function has too many arguments for no real reason - all
callers use genl_info to get them anyway. Just pass the genl_info down to
genl_notify.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On Mon, Sep 21, 2015 at 02:20:22PM -0400, Tejun Heo wrote:
>
> store_release and load_acquire are different from the usual memory
> barriers and can't be paired this way. You have to pair store_release
> and load_acquire. Besides, it isn't a particularly good idea to
OK I've decided to drop the acquire/release helpers as they don't
help us at all and simply pessimises the code by using full memory
barriers (on some architectures) where only a write or read barrier
is needed.
> depend on memory barriers embedded in other data structures like the
> above. Here, especially, rhashtable_insert() would have write barrier
> *before* the entry is hashed not necessarily *after*, which means that
> in the above case, a socket which appears to have set bound to a
> reader might not visible when the reader tries to look up the socket
> on the hashtable.
But you are right we do need an explicit write barrier here to
ensure that the hashing is visible.
> There's no reason to be overly smart here. This isn't a crazy hot
> path, write barriers tend to be very cheap, store_release more so.
> Please just do smp_store_release() and note what it's paired with.
It's not about being overly smart. It's about actually understanding
what's going on with the code. I've seen too many instances of
people simply sprinkling synchronisation primitives around without
any knowledge of what is happening underneath, which is just a recipe
for creating hard-to-debug races.
> > @@ -1539,7 +1546,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
> > }
> > }
> >
> > - if (!nlk->portid) {
> > + if (!nlk->bound) {
>
> I don't think you can skip load_acquire here just because this is the
> second deref of the variable. That doesn't change anything. Race
> condition could still happen between the first and second tests and
> skipping the second would lead to the same kind of bug.
The reason this one is OK is because we do not use nlk->portid or
try to get nlk from the hash table before we return to user-space.
However, there is a real bug here that none of these acquire/release
helpers discovered. The two bound tests here used to be a single
one. Now that they are separate it is entirely possible for another
thread to come in the middle and bind the socket. So we need to
repeat the portid check in order to maintain consistency.
> > @@ -1587,7 +1594,7 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
> > !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
> > return -EPERM;
> >
> > - if (!nlk->portid)
> > + if (!nlk->bound)
>
> Don't we need load_acquire here too? Is this path holding a lock
> which makes that unnecessary?
Ditto.
---8<---
The commit 1f770c0a09 ("netlink:
Fix autobind race condition that leads to zero port ID") created
some new races that can occur due to inconcsistencies between the
two port IDs.
Tejun is right that a barrier is unavoidable. Therefore I am
reverting to the original patch that used a boolean to indicate
that a user netlink socket has been bound.
Barriers have been added where necessary to ensure that a valid
portid and the hashed socket is visible.
I have also changed netlink_insert to only return EBUSY if the
socket is bound to a portid different to the requested one. This
combined with only reading nlk->bound once in netlink_bind fixes
a race where two threads that bind the socket at the same time
with different port IDs may both succeed.
Fixes: 1f770c0a09 ("netlink: Fix autobind race condition that leads to zero port ID")
Reported-by: Tejun Heo <tj@kernel.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Nacked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Siva Mannem <siva.mannem.lnx@gmail.com>
Signed-off-by: Scott Feldman <sfeldma@gmail.com>
Acked-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Premkumar Jonnala <pjonnala@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 7d82410950 ("virtio: add explicit big-endian support to memory
accessors") accidentally changed the virtio_net header used by
AF_PACKET with PACKET_VNET_HDR from host-endian to big-endian.
Since virtio_legacy_is_little_endian() is a very long identifier,
define a vio_le macro and use that throughout the code instead of the
hard-coded 'false' for little-endian.
This restores the ABI to match 4.1 and earlier kernels, and makes my
test program work again.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Drivers might call napi_disable while not holding the napi instance poll_lock.
In those instances, its possible for a race condition to exist between
poll_one_napi and napi_disable. That is to say, poll_one_napi only tests the
NAPI_STATE_SCHED bit to see if there is work to do during a poll, and as such
the following may happen:
CPU0 CPU1
ndo_tx_timeout napi_poll_dev
napi_disable poll_one_napi
test_and_set_bit (ret 0)
test_bit (ret 1)
reset adapter napi_poll_routine
If the adapter gets a tx timeout without a napi instance scheduled, its possible
for the adapter to think it has exclusive access to the hardware (as the napi
instance is now scheduled via the napi_disable call), while the netpoll code
thinks there is simply work to do. The result is parallel hardware access
leading to corrupt data structures in the driver, and a crash.
Additionaly, there is another, more critical race between netpoll and
napi_disable. The disabled napi state is actually identical to the scheduled
state for a given napi instance. The implication being that, if a napi instance
is disabled, a netconsole instance would see the napi state of the device as
having been scheduled, and poll it, likely while the driver was dong something
requiring exclusive access. In the case above, its fairly clear that not having
the rings in a state ready to be polled will cause any number of crashes.
The fix should be pretty easy. netpoll uses its own bit to indicate that that
the napi instance is in a state of being serviced by netpoll (NAPI_STATE_NPSVC).
We can just gate disabling on that bit as well as the sched bit. That should
prevent netpoll from conducting a napi poll if we convert its set bit to a
test_and_set_bit operation to provide mutual exclusion
Change notes:
V2)
Remove a trailing whtiespace
Resubmit with proper subject prefix
V3)
Clean up spacing nits
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: jmaxwell@redhat.com
Tested-by: jmaxwell@redhat.com
Signed-off-by: David S. Miller <davem@davemloft.net>
Eric Dumazet