Most attributes can be read safely without any locking.
A race might lead to a slightly out-dated value, but nothing wrong.
We already have locking in some places where needed.
All that remains is can_clear_show(), behind_writes_used_show()
and action_show() which are easily fixed.
Signed-off-by: NeilBrown <neilb@suse.de>
It is important that mddev->private isn't freed while
a sysfs attribute function is accessing it.
So use mddev->lock to protect the setting of ->private to NULL, and
take that lock when checking ->private for NULL and de-referencing it
in the sysfs access functions.
This only applies to the read ('show') side of access. Write
access will be handled separately.
Signed-off-by: NeilBrown <neilb@suse.de>
The only access in md_seq_show that could suffer from races
not protected by ->lock is walking the rdev list.
This can receive sufficient protection from 'rcu'.
So use rdev_for_each_rcu() and get rid of mddev_lock().
Now reading /proc/mdstat will never block in md_seq_show.
Signed-off-by: NeilBrown <neilb@suse.de>
->pers is already protected by ->reconfig_mutex, and
cannot possibly change when there are threads running or
outstanding IO.
However there are some places where we access ->pers
not in a thread or IO context, and where ->reconfig_mutex
is unnecessarily heavy-weight: level_show and md_seq_show().
So protect all changes, and those accesses, with ->lock.
This is a step toward taking those accesses out from under
reconfig_mutex.
[Fixed missing "mddev->pers" -> "pers" conversion, thanks to
Dan Carpenter <dan.carpenter@oracle.com>]
Signed-off-by: NeilBrown <neilb@suse.de>
Gather all the changes that can happen atomically and might
be relevant to other code into one place. This will
make it easier to refine the locking.
Note that this puts quite a few things between mddev_detach()
and ->free(). Enabling this was the point of some recent patches.
Signed-off-by: NeilBrown <neilb@suse.de>
Now that the ->stop function only frees the private data,
rename is accordingly.
Also pass in the private pointer as an arg rather than using
mddev->private. This flexibility will be useful in level_store().
Finally, don't clear ->private. It doesn't make sense to clear
it seeing that isn't what we free, and it is no longer necessary
to clear ->private (it was some time ago before ->to_remove was
introduced).
Setting ->to_remove in ->free() is a bit of a wart, but not a
big problem at the moment.
Signed-off-by: NeilBrown <neilb@suse.de>
Each md personality has a 'stop' operation which does two
things:
1/ it finalizes some aspects of the array to ensure nothing
is accessing the ->private data
2/ it frees the ->private data.
All the steps in '1' can apply to all arrays and so can be
performed in common code.
This is useful as in the case where we change the personality which
manages an array (in level_store()), it would be helpful to do
step 1 early, and step 2 later.
So split the 'step 1' functionality out into a new mddev_detach().
Signed-off-by: NeilBrown <neilb@suse.de>
The use of 'rcu' to protect accesses to ->private_data so that
the ->private_data could be updated predates the introduction
of mddev_suspend/mddev_resume.
These are a cleaner mechanism for providing stability while
swapping in a new ->private data - it is used by level_store()
to support changing of raid levels.
So get rid of the RCU stuff and just use mddev_suspend, mddev_resume.
As these function call ->quiesce(), we add an empty function for
linear just like for raid0.
Signed-off-by: NeilBrown <neilb@suse.de>
There is no locking around calls to merge_bvec_fn(), so
it is possible that calls which coincide with a level (or personality)
change could go wrong.
So create a central dispatch point for these functions and use
rcu_read_lock().
If the array is suspended, reject any merge that can be rejected.
If not, we know it is safe to call the function.
Signed-off-by: NeilBrown <neilb@suse.de>
There is currently no locking around calls to the 'congested'
bdi function. If called at an awkward time while an array is
being converted from one level (or personality) to another, there
is a tiny chance of running code in an unreferenced module etc.
So add a 'congested' function to the md_personality operations
structure, and call it with appropriate locking from a central
'mddev_congested'.
When the array personality is changing the array will be 'suspended'
so no IO is processed.
If mddev_congested detects this, it simply reports that the
array is congested, which is a safe guess.
As mddev_suspend calls synchronize_rcu(), mddev_congested can
avoid races by included the whole call inside an rcu_read_lock()
region.
This require that the congested functions for all subordinate devices
can be run under rcu_lock. Fortunately this is the case.
Signed-off-by: NeilBrown <neilb@suse.de>
This lock is used for (slightly) more than helping with writing
superblocks, and it will soon be extended further. So the
name is inappropriate.
Also, the _irq variant hasn't been needed since 2.6.37 as it is
never taking from interrupt or bh context.
So:
-rename write_lock to lock
-document what it protects
-remove _irq ... except in md_flush_request() as there
is no wait_event_lock() (with no _irq). This can be
cleaned up after appropriate changes to wait.h.
Signed-off-by: NeilBrown <neilb@suse.de>
That last condition is unclear and over cautious.
There are two related issues here.
If a partial write is destined for a missing device, then
either RMW or RCW can work. We must read all the available
block. Only then can the missing blocks be calculated, and
then the parity update performed.
If RMW is not an option, then there is a complication even
without partial writes. If we would need to read a missing
device to perform the reconstruction, then we must first read every
block so the missing device data can be computed.
This is the case for RAID6 (Which currently does not support
RMW) and for times when we don't trust the parity (after a crash)
and so are in the process of resyncing it.
So make these two cases more clear and separate, and perform
the relevant tests more thoroughly.
Signed-off-by: NeilBrown <neilb@suse.de>
Both the last two cases are only relevant if something has failed and
something needs to be written (but not over-written), and if it is OK
to pre-read blocks at this point. So factor out those tests and
explain them.
Signed-off-by: NeilBrown <neilb@suse.de>
Some of the conditions in need_this_block have very straight
forward motivation. Separate those out and document them.
Signed-off-by: NeilBrown <neilb@suse.de>
fetch_block() has a very large and hard to read 'if' condition.
Separate it into its own function so that it can be
made more readable.
Signed-off-by: NeilBrown <neilb@suse.de>
67f455486d introduced a call to
md_wakeup_thread() when adding to the delayed_list. However the md
thread is woken up unconditionally just below.
Remove the unnecessary wakeup call.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Just like for AVX2 (which simply needs an #if -> #ifdef conversion),
SSSE3 assembler support should be checked for before using it.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Jim Kukunas <james.t.kukunas@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NeilBrown <neilb@suse.de>
commit 8eb23b9f35
sched: Debug nested sleeps
causes false-positive warnings in RAID5 code.
This annotation removes them and adds a comment
explaining why there is no real problem.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
If a non-page-aligned write is destined for a device which
is missing/faulty, we can deadlock.
As the target device is missing, a read-modify-write cycle
is not possible.
As the write is not for a full-page, a recontruct-write cycle
is not possible.
This should be handled by logic in fetch_block() which notices
there is a non-R5_OVERWRITE write to a missing device, and so
loads all blocks.
However since commit 67f455486d, that code requires
STRIPE_PREREAD_ACTIVE before it will active, and those circumstances
never set STRIPE_PREREAD_ACTIVE.
So: in handle_stripe_dirtying, if neither rmw or rcw was possible,
set STRIPE_DELAYED, which will cause STRIPE_PREREAD_ACTIVE be set
after a suitable delay.
Fixes: 67f455486d
Cc: stable@vger.kernel.org (v3.16+)
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Tested-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Pull networking fixes from David Miller:
1) Don't OOPS on socket AIO, from Christoph Hellwig.
2) Scheduled scans should be aborted upon RFKILL, from Emmanuel
Grumbach.
3) Fix sleep in atomic context in kvaser_usb, from Ahmed S Darwish.
4) Fix RCU locking across copy_to_user() in bpf code, from Alexei
Starovoitov.
5) Lots of crash, memory leak, short TX packet et al bug fixes in
sh_eth from Ben Hutchings.
6) Fix memory corruption in SCTP wrt. INIT collitions, from Daniel
Borkmann.
7) Fix return value logic for poll handlers in netxen, enic, and bnx2x.
From Eric Dumazet and Govindarajulu Varadarajan.
8) Header length calculation fix in mac80211 from Fred Chou.
9) mv643xx_eth doesn't handle highmem correctly in non-TSO code paths.
From Ezequiel Garcia.
10) udp_diag has bogus logic in it's hash chain skipping, copy same fix
tcp diag used. From Herbert Xu.
11) amd-xgbe programs wrong rx flow control register, from Thomas
Lendacky.
12) Fix race leading to use after free in ping receive path, from Subash
Abhinov Kasiviswanathan.
13) Cache redirect routes otherwise we can get a heavy backlog of rcu
jobs liberating DST_NOCACHE entries. From Hannes Frederic Sowa.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (48 commits)
net: don't OOPS on socket aio
stmmac: prevent probe drivers to crash kernel
bnx2x: fix napi poll return value for repoll
ipv6: replacing a rt6_info needs to purge possible propagated rt6_infos too
sh_eth: Fix DMA-API usage for RX buffers
sh_eth: Check for DMA mapping errors on transmit
sh_eth: Ensure DMA engines are stopped before freeing buffers
sh_eth: Remove RX overflow log messages
ping: Fix race in free in receive path
udp_diag: Fix socket skipping within chain
can: kvaser_usb: Fix state handling upon BUS_ERROR events
can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT
can: kvaser_usb: Send correct context to URB completion
can: kvaser_usb: Do not sleep in atomic context
ipv4: try to cache dst_entries which would cause a redirect
samples: bpf: relax test_maps check
bpf: rcu lock must not be held when calling copy_to_user()
net: sctp: fix slab corruption from use after free on INIT collisions
net: mv643xx_eth: Fix highmem support in non-TSO egress path
sh_eth: Fix serialisation of interrupt disable with interrupt & NAPI handlers
...
In the case when alloc_netdev fails we return NULL to a caller. But there is no
check for NULL in the probe drivers. This patch changes NULL to an error
pointer. The function description is amended to reflect what we may get
returned.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
unloading: this broke with new atomic refcounting. The code is still
suspicious, but this solves the WARN_ON().
Thanks,
Rusty.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=JI7o
-----END PGP SIGNATURE-----
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull one more module fix from Rusty Russell:
"SCSI was using module_refcount() to figure out when the module was
unloading: this broke with new atomic refcounting. The code is still
suspicious, but this solves the WARN_ON()"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
scsi: always increment reference count
With the commit d75b1ade56 ("net: less interrupt masking in NAPI") napi
repoll is done only when work_done == budget. When in busy_poll is we return 0
in napi_poll. We should return budget.
Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steffen Klassert says:
====================
ipsec 2015-01-26
Just two small fixes for _decode_session6() where we
might decode to wrong header information in some rare
situations.
Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Lubomir Rintel reported that during replacing a route the interface
reference counter isn't correctly decremented.
To quote bug <https://bugzilla.kernel.org/show_bug.cgi?id=91941>:
| [root@rhel7-5 lkundrak]# sh -x lal
| + ip link add dev0 type dummy
| + ip link set dev0 up
| + ip link add dev1 type dummy
| + ip link set dev1 up
| + ip addr add 2001:db8:8086::2/64 dev dev0
| + ip route add 2001:db8:8086::/48 dev dev0 proto static metric 20
| + ip route add 2001:db8:8088::/48 dev dev1 proto static metric 10
| + ip route replace 2001:db8:8086::/48 dev dev1 proto static metric 20
| + ip link del dev0 type dummy
| Message from syslogd@rhel7-5 at Jan 23 10:54:41 ...
| kernel:unregister_netdevice: waiting for dev0 to become free. Usage count = 2
|
| Message from syslogd@rhel7-5 at Jan 23 10:54:51 ...
| kernel:unregister_netdevice: waiting for dev0 to become free. Usage count = 2
During replacement of a rt6_info we must walk all parent nodes and check
if the to be replaced rt6_info got propagated. If so, replace it with
an alive one.
Fixes: 4a287eba2d ("IPv6 routing, NLM_F_* flag support: REPLACE and EXCL flags support, warn about missing CREATE flag")
Reported-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Tested-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Hutchings says:
====================
Fixes for sh_eth #3
I'm continuing review and testing of Ethernet support on the R-Car H2
chip. This series fixes the last of the more serious issues I've found.
These are not tested on any of the other supported chips.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
- Use the return value of dma_map_single(), rather than calling
virt_to_page() separately
- Check for mapping failue
- Call dma_unmap_single() rather than dma_sync_single_for_cpu()
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
dma_map_single() may fail if an IOMMU or swiotlb is in use, so
we need to check for this.
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently we try to clear EDRRR and EDTRR and immediately continue to
free buffers. This is unsafe because:
- In general, register writes are not serialised with DMA, so we still
have to wait for DMA to complete somehow
- The R8A7790 (R-Car H2) manual states that the TX running flag cannot
be cleared by writing to EDTRR
- The same manual states that clearing the RX running flag only stops
RX DMA at the next packet boundary
I applied this patch to the driver to detect DMA writes to freed
buffers:
> --- a/drivers/net/ethernet/renesas/sh_eth.c
> +++ b/drivers/net/ethernet/renesas/sh_eth.c
> @@ -1098,7 +1098,14 @@ static void sh_eth_ring_free(struct net_device *ndev)
> /* Free Rx skb ringbuffer */
> if (mdp->rx_skbuff) {
> for (i = 0; i < mdp->num_rx_ring; i++)
> + memcpy(mdp->rx_skbuff[i]->data,
> + "Hello, world", 12);
> + msleep(100);
> + for (i = 0; i < mdp->num_rx_ring; i++) {
> + WARN_ON(memcmp(mdp->rx_skbuff[i]->data,
> + "Hello, world", 12));
> dev_kfree_skb(mdp->rx_skbuff[i]);
> + }
> }
> kfree(mdp->rx_skbuff);
> mdp->rx_skbuff = NULL;
then ran the loop:
while ethtool -G eth0 rx 128 ; ethtool -G eth0 rx 64; do echo -n .; done
and 'ping -f' toward the sh_eth port from another machine. The
warning fired several times a minute.
To fix these issues:
- Deactivate all TX descriptors rather than writing to EDTRR
- As there seems to be no way of telling when RX DMA is stopped,
perform a soft reset to ensure that both DMA enginess are stopped
- To reduce the possibility of the reset truncating a transmitted
frame, disable egress and wait a reasonable time to reach a
packet boundary before resetting
- Update statistics before resetting
(The 'reasonable time' does not allow for CS/CD in half-duplex
mode, but half-duplex no longer seems reasonable!)
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
If RX traffic is overflowing the FIFO or DMA ring, logging every time
this happens just makes things worse. These errors are visible in the
statistics anyway.
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=S/gP
-----END PGP SIGNATURE-----
Merge tag 'linux-can-fixes-for-3.19-20150127' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can
Marc Kleine-Budde says:
====================
pull-request: can 2015-01-27
this is another pull request for net/master which consists of 4 patches.
All 4 patches are contributed by Ahmed S. Darwish, he fixes more problems in
the kvaser_usb driver.
David, please merge net/master to net-next/master, as we have more kvaser_usb
patches in the queue, that target net-next.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
An exception is seen in ICMP ping receive path where the skb
destructor sock_rfree() tries to access a freed socket. This happens
because ping_rcv() releases socket reference with sock_put() and this
internally frees up the socket. Later icmp_rcv() will try to free the
skb and as part of this, skb destructor is called and which leads
to a kernel panic as the socket is freed already in ping_rcv().
-->|exception
-007|sk_mem_uncharge
-007|sock_rfree
-008|skb_release_head_state
-009|skb_release_all
-009|__kfree_skb
-010|kfree_skb
-011|icmp_rcv
-012|ip_local_deliver_finish
Fix this incorrect free by cloning this skb and processing this cloned
skb instead.
This patch was suggested by Eric Dumazet
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While working on rhashtable walking I noticed that the UDP diag
dumping code is buggy. In particular, the socket skipping within
a chain never happens, even though we record the number of sockets
that should be skipped.
As this code was supposedly copied from TCP, this patch does what
TCP does and resets num before we walk a chain.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While being in an ERROR_WARNING state, and receiving further
bus error events with error counters still in the ERROR_WARNING
range of 97-127 inclusive, the state handling code erroneously
reverts back to ERROR_ACTIVE.
Per the CAN standard, only revert to ERROR_ACTIVE when the
error counters are less than 96.
Moreover, in certain Kvaser models, the BUS_ERROR flag is
always set along with undefined bits in the M16C status
register. Thus use bitwise operators instead of full equality
for checking that register against bus errors.
Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
On some x86 laptops, plugging a Kvaser device again after an
unplug makes the firmware always ignore the very first command.
For such a case, provide some room for retries instead of
completely exiting the driver init code.
Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Send expected argument to the URB completion hander: a CAN
netdevice instead of the network interface private context
`kvaser_usb_net_priv'.
This was discovered by having some garbage in the kernel
log in place of the netdevice names: can0 and can1.
Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Upon receiving a hardware event with the BUS_RESET flag set,
the driver kills all of its anchored URBs and resets all of
its transmit URB contexts.
Unfortunately it does so under the context of URB completion
handler `kvaser_usb_read_bulk_callback()', which is often
called in an atomic context.
While the device is flooded with many received error packets,
usb_kill_urb() typically sleeps/reschedules till the transfer
request of each killed URB in question completes, leading to
the sleep in atomic bug. [3]
In v2 submission of the original driver patch [1], it was
stated that the URBs kill and tx contexts reset was needed
since we don't receive any tx acknowledgments later and thus
such resources will be locked down forever. Fortunately this
is no longer needed since an earlier bugfix in this patch
series is now applied: all tx URB contexts are reset upon CAN
channel close. [2]
Moreover, a BUS_RESET is now treated _exactly_ like a BUS_OFF
event, which is the recommended handling method advised by
the device manufacturer.
[1] http://article.gmane.org/gmane.linux.network/239442http://www.webcitation.org/6Vr2yagAQ
[2] can: kvaser_usb: Reset all URB tx contexts upon channel close
889b77f7fd
[3] Stacktrace:
<IRQ> [<ffffffff8158de87>] dump_stack+0x45/0x57
[<ffffffff8158b60c>] __schedule_bug+0x41/0x4f
[<ffffffff815904b1>] __schedule+0x5f1/0x700
[<ffffffff8159360a>] ? _raw_spin_unlock_irqrestore+0xa/0x10
[<ffffffff81590684>] schedule+0x24/0x70
[<ffffffff8147d0a5>] usb_kill_urb+0x65/0xa0
[<ffffffff81077970>] ? prepare_to_wait_event+0x110/0x110
[<ffffffff8147d7d8>] usb_kill_anchored_urbs+0x48/0x80
[<ffffffffa01f4028>] kvaser_usb_unlink_tx_urbs+0x18/0x50 [kvaser_usb]
[<ffffffffa01f45d0>] kvaser_usb_rx_error+0xc0/0x400 [kvaser_usb]
[<ffffffff8108b14a>] ? vprintk_default+0x1a/0x20
[<ffffffffa01f5241>] kvaser_usb_read_bulk_callback+0x4c1/0x5f0 [kvaser_usb]
[<ffffffff8147a73e>] __usb_hcd_giveback_urb+0x5e/0xc0
[<ffffffff8147a8a1>] usb_hcd_giveback_urb+0x41/0x110
[<ffffffffa0008748>] finish_urb+0x98/0x180 [ohci_hcd]
[<ffffffff810cd1a7>] ? acct_account_cputime+0x17/0x20
[<ffffffff81069f65>] ? local_clock+0x15/0x30
[<ffffffffa000a36b>] ohci_work+0x1fb/0x5a0 [ohci_hcd]
[<ffffffff814fbb31>] ? process_backlog+0xb1/0x130
[<ffffffffa000cd5b>] ohci_irq+0xeb/0x270 [ohci_hcd]
[<ffffffff81479fc1>] usb_hcd_irq+0x21/0x30
[<ffffffff8108bfd3>] handle_irq_event_percpu+0x43/0x120
[<ffffffff8108c0ed>] handle_irq_event+0x3d/0x60
[<ffffffff8108ec84>] handle_fasteoi_irq+0x74/0x110
[<ffffffff81004dfd>] handle_irq+0x1d/0x30
[<ffffffff81004727>] do_IRQ+0x57/0x100
[<ffffffff8159482a>] common_interrupt+0x6a/0x6a
Signed-off-by: Ahmed S. Darwish <ahmed.darwish@valeo.com>
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
* fix station double-removal when suspending while associating
* fix the HT (802.11n) header length calculation
* fix the CCK radiotap flag used for monitoring, a pretty
old regression but a simple one-liner
* fix per-station group-key handling
-----BEGIN PGP SIGNATURE-----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=DhIp
-----END PGP SIGNATURE-----
Merge tag 'mac80211-for-davem-2015-01-23' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211
Another set of last-minute fixes:
* fix station double-removal when suspending while associating
* fix the HT (802.11n) header length calculation
* fix the CCK radiotap flag used for monitoring, a pretty
old regression but a simple one-liner
* fix per-station group-key handling
Signed-off-by: David S. Miller <davem@davemloft.net>
Not caching dst_entries which cause redirects could be exploited by hosts
on the same subnet, causing a severe DoS attack. This effect aggravated
since commit f886497212 ("ipv4: fix dst race in sk_dst_get()").
Lookups causing redirects will be allocated with DST_NOCACHE set which
will force dst_release to free them via RCU. Unfortunately waiting for
RCU grace period just takes too long, we can end up with >1M dst_entries
waiting to be released and the system will run OOM. rcuos threads cannot
catch up under high softirq load.
Attaching the flag to emit a redirect later on to the specific skb allows
us to cache those dst_entries thus reducing the pressure on allocation
and deallocation.
This issue was discovered by Marcelo Leitner.
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Marcelo Leitner <mleitner@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexei Starovoitov says:
====================
bpf: fix two bugs
Michael Holzheu caught two issues (in bpf syscall and in the test).
Fix them. Details in corresponding patches.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
hash map is unordered, so get_next_key() iterator shouldn't
rely on particular order of elements. So relax this test.
Fixes: ffb65f27a1 ("bpf: add a testsuite for eBPF maps")
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
BUG: sleeping function called from invalid context at mm/memory.c:3732
in_atomic(): 0, irqs_disabled(): 0, pid: 671, name: test_maps
1 lock held by test_maps/671:
#0: (rcu_read_lock){......}, at: [<0000000000264190>] map_lookup_elem+0xe8/0x260
Call Trace:
([<0000000000115b7e>] show_trace+0x12e/0x150)
[<0000000000115c40>] show_stack+0xa0/0x100
[<00000000009b163c>] dump_stack+0x74/0xc8
[<000000000017424a>] ___might_sleep+0x23a/0x248
[<00000000002b58e8>] might_fault+0x70/0xe8
[<0000000000264230>] map_lookup_elem+0x188/0x260
[<0000000000264716>] SyS_bpf+0x20e/0x840
Fix it by allocating temporary buffer to store map element value.
Fixes: db20fd2b01 ("bpf: add lookup/update/delete/iterate methods to BPF maps")
Reported-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When hitting an INIT collision case during the 4WHS with AUTH enabled, as
already described in detail in commit 1be9a950c6 ("net: sctp: inherit
auth_capable on INIT collisions"), it can happen that we occasionally
still remotely trigger the following panic on server side which seems to
have been uncovered after the fix from commit 1be9a950c6 ...
[ 533.876389] BUG: unable to handle kernel paging request at 00000000ffffffff
[ 533.913657] IP: [<ffffffff811ac385>] __kmalloc+0x95/0x230
[ 533.940559] PGD 5030f2067 PUD 0
[ 533.957104] Oops: 0000 [#1] SMP
[ 533.974283] Modules linked in: sctp mlx4_en [...]
[ 534.939704] Call Trace:
[ 534.951833] [<ffffffff81294e30>] ? crypto_init_shash_ops+0x60/0xf0
[ 534.984213] [<ffffffff81294e30>] crypto_init_shash_ops+0x60/0xf0
[ 535.015025] [<ffffffff8128c8ed>] __crypto_alloc_tfm+0x6d/0x170
[ 535.045661] [<ffffffff8128d12c>] crypto_alloc_base+0x4c/0xb0
[ 535.074593] [<ffffffff8160bd42>] ? _raw_spin_lock_bh+0x12/0x50
[ 535.105239] [<ffffffffa0418c11>] sctp_inet_listen+0x161/0x1e0 [sctp]
[ 535.138606] [<ffffffff814e43bd>] SyS_listen+0x9d/0xb0
[ 535.166848] [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b
... or depending on the the application, for example this one:
[ 1370.026490] BUG: unable to handle kernel paging request at 00000000ffffffff
[ 1370.026506] IP: [<ffffffff811ab455>] kmem_cache_alloc+0x75/0x1d0
[ 1370.054568] PGD 633c94067 PUD 0
[ 1370.070446] Oops: 0000 [#1] SMP
[ 1370.085010] Modules linked in: sctp kvm_amd kvm [...]
[ 1370.963431] Call Trace:
[ 1370.974632] [<ffffffff8120f7cf>] ? SyS_epoll_ctl+0x53f/0x960
[ 1371.000863] [<ffffffff8120f7cf>] SyS_epoll_ctl+0x53f/0x960
[ 1371.027154] [<ffffffff812100d3>] ? anon_inode_getfile+0xd3/0x170
[ 1371.054679] [<ffffffff811e3d67>] ? __alloc_fd+0xa7/0x130
[ 1371.080183] [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b
With slab debugging enabled, we can see that the poison has been overwritten:
[ 669.826368] BUG kmalloc-128 (Tainted: G W ): Poison overwritten
[ 669.826385] INFO: 0xffff880228b32e50-0xffff880228b32e50. First byte 0x6a instead of 0x6b
[ 669.826414] INFO: Allocated in sctp_auth_create_key+0x23/0x50 [sctp] age=3 cpu=0 pid=18494
[ 669.826424] __slab_alloc+0x4bf/0x566
[ 669.826433] __kmalloc+0x280/0x310
[ 669.826453] sctp_auth_create_key+0x23/0x50 [sctp]
[ 669.826471] sctp_auth_asoc_create_secret+0xcb/0x1e0 [sctp]
[ 669.826488] sctp_auth_asoc_init_active_key+0x68/0xa0 [sctp]
[ 669.826505] sctp_do_sm+0x29d/0x17c0 [sctp] [...]
[ 669.826629] INFO: Freed in kzfree+0x31/0x40 age=1 cpu=0 pid=18494
[ 669.826635] __slab_free+0x39/0x2a8
[ 669.826643] kfree+0x1d6/0x230
[ 669.826650] kzfree+0x31/0x40
[ 669.826666] sctp_auth_key_put+0x19/0x20 [sctp]
[ 669.826681] sctp_assoc_update+0x1ee/0x2d0 [sctp]
[ 669.826695] sctp_do_sm+0x674/0x17c0 [sctp]
Since this only triggers in some collision-cases with AUTH, the problem at
heart is that sctp_auth_key_put() on asoc->asoc_shared_key is called twice
when having refcnt 1, once directly in sctp_assoc_update() and yet again
from within sctp_auth_asoc_init_active_key() via sctp_assoc_update() on
the already kzfree'd memory, which is also consistent with the observation
of the poison decrease from 0x6b to 0x6a (note: the overwrite is detected
at a later point in time when poison is checked on new allocation).
Reference counting of auth keys revisited:
Shared keys for AUTH chunks are being stored in endpoints and associations
in endpoint_shared_keys list. On endpoint creation, a null key is being
added; on association creation, all endpoint shared keys are being cached
and thus cloned over to the association. struct sctp_shared_key only holds
a pointer to the actual key bytes, that is, struct sctp_auth_bytes which
keeps track of users internally through refcounting. Naturally, on assoc
or enpoint destruction, sctp_shared_key are being destroyed directly and
the reference on sctp_auth_bytes dropped.
User space can add keys to either list via setsockopt(2) through struct
sctp_authkey and by passing that to sctp_auth_set_key() which replaces or
adds a new auth key. There, sctp_auth_create_key() creates a new sctp_auth_bytes
with refcount 1 and in case of replacement drops the reference on the old
sctp_auth_bytes. A key can be set active from user space through setsockopt()
on the id via sctp_auth_set_active_key(), which iterates through either
endpoint_shared_keys and in case of an assoc, invokes (one of various places)
sctp_auth_asoc_init_active_key().
sctp_auth_asoc_init_active_key() computes the actual secret from local's
and peer's random, hmac and shared key parameters and returns a new key
directly as sctp_auth_bytes, that is asoc->asoc_shared_key, plus drops
the reference if there was a previous one. The secret, which where we
eventually double drop the ref comes from sctp_auth_asoc_set_secret() with
intitial refcount of 1, which also stays unchanged eventually in
sctp_assoc_update(). This key is later being used for crypto layer to
set the key for the hash in crypto_hash_setkey() from sctp_auth_calculate_hmac().
To close the loop: asoc->asoc_shared_key is freshly allocated secret
material and independant of the sctp_shared_key management keeping track
of only shared keys in endpoints and assocs. Hence, also commit 4184b2a79a
("net: sctp: fix memory leak in auth key management") is independant of
this bug here since it concerns a different layer (though same structures
being used eventually). asoc->asoc_shared_key is reference dropped correctly
on assoc destruction in sctp_association_free() and when active keys are
being replaced in sctp_auth_asoc_init_active_key(), it always has a refcount
of 1. Hence, it's freed prematurely in sctp_assoc_update(). Simple fix is
to remove that sctp_auth_key_put() from there which fixes these panics.
Fixes: 730fc3d05c ("[SCTP]: Implete SCTP-AUTH parameter processing")
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge misc fixes from Andrew Morton:
"Six fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
drivers/rtc/rtc-s5m.c: terminate s5m_rtc_id array with empty element
printk: add dummy routine for when CONFIG_PRINTK=n
mm/vmscan: fix highidx argument type
memcg: remove extra newlines from memcg oom kill log
x86, build: replace Perl script with Shell script
mm: page_alloc: embed OOM killing naturally into allocation slowpath
Commit 69ad0dd7af
Author: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Date: Mon May 19 13:59:59 2014 -0300
net: mv643xx_eth: Use dma_map_single() to map the skb fragments
caused a nasty regression by removing the support for highmem skb
fragments. By using page_address() to get the address of a fragment's
page, we are assuming a lowmem page. However, such assumption is incorrect,
as fragments can be in highmem pages, resulting in very nasty issues.
This commit fixes this by using the skb_frag_dma_map() helper,
which takes care of mapping the skb fragment properly. Additionally,
the type of mapping is now tracked, so it can be unmapped using
dma_unmap_page or dma_unmap_single when appropriate.
This commit also fixes the error path in txq_init() to release the
resources properly.
Fixes: 69ad0dd7af ("net: mv643xx_eth: Use dma_map_single() to map the skb fragments")
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Hutchings says:
====================
Fixes for sh_eth #2
I'm continuing review and testing of Ethernet support on the R-Car H2
chip. This series fixes more of the issues I've found, but it won't be
the last set.
These are not tested on any of the other supported chips.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to stop the RX path accessing the RX ring while it's being
stopped or resized, we clear the interrupt mask (EESIPR) and then call
free_irq() or synchronise_irq(). This is insufficient because the
interrupt handler or NAPI poller may set EESIPR again after we clear
it. Also, in sh_eth_set_ringparam() we currently don't disable NAPI
polling at all.
I could easily trigger a crash by running the loop:
while ethtool -G eth0 rx 128 && ethtool -G eth0 rx 64; do echo -n .; done
and 'ping -f' toward the sh_eth port from another machine.
To fix this:
- Add a software flag (irq_enabled) to signal whether interrupts
should be enabled
- In the interrupt handler, if the flag is clear then clear EESIPR
and return
- In the NAPI poller, if the flag is clear then don't set EESIPR
- Set the flag before enabling interrupts in sh_eth_dev_init() and
sh_eth_set_ringparam()
- Clear the flag and serialise with the interrupt and NAPI
handlers before clearing EESIPR in sh_eth_close() and
sh_eth_set_ringparam()
After this, I could run the loop for 100,000 iterations successfully.
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
