Commit Graph
723511 Commits
Author SHA1 Message Date
Thomas Gleixner 5d62c183f9 nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()
The conditions in irq_exit() to invoke tick_nohz_irq_exit() which
subsequently invokes tick_nohz_stop_sched_tick() are:

  if ((idle_cpu(cpu) && !need_resched()) || tick_nohz_full_cpu(cpu))

If need_resched() is not set, but a timer softirq is pending then this is
an indication that the softirq code punted and delegated the execution to
softirqd. need_resched() is not true because the current interrupted task
takes precedence over softirqd.

Invoking tick_nohz_irq_exit() in this case can cause an endless loop of
timer interrupts because the timer wheel contains an expired timer, but
softirqs are not yet executed. So it returns an immediate expiry request,
which causes the timer to fire immediately again. Lather, rinse and
repeat....

Prevent that by adding a check for a pending timer soft interrupt to the
conditions in tick_nohz_stop_sched_tick() which avoid calling
get_next_timer_interrupt(). That keeps the tick sched timer on the tick and
prevents a repetitive programming of an already expired timer.

Reported-by: Sebastian Siewior <bigeasy@linutronix.d>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712272156050.2431@nanos
2017-12-29 23:13:10 +01:00
Thomas Gleixner 26456f87ac timers: Reinitialize per cpu bases on hotplug
The timer wheel bases are not (re)initialized on CPU hotplug. That leaves
them with a potentially stale clk and next_expiry valuem, which can cause
trouble then the CPU is plugged.

Add a prepare callback which forwards the clock, sets next_expiry to far in
the future and reset the control flags to a known state.

Set base->must_forward_clk so the first timer which is queued will try to
forward the clock to current jiffies.

Fixes: 500462a9de ("timers: Switch to a non-cascading wheel")
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1712272152200.2431@nanos
2017-12-29 23:13:09 +01:00
Anna-Maria Gleixner ced6d5c11d timers: Use deferrable base independent of base::nohz_active
During boot and before base::nohz_active is set in the timer bases, deferrable
timers are enqueued into the standard timer base. This works correctly as
long as base::nohz_active is false.

Once it base::nohz_active is set and a timer which was enqueued before that
is accessed the lock selector code choses the lock of the deferred
base. This causes unlocked access to the standard base and in case the
timer is removed it does not clear the pending flag in the standard base
bitmap which causes get_next_timer_interrupt() to return bogus values.

To prevent that, the deferrable timers must be enqueued in the deferrable
base, even when base::nohz_active is not set. Those deferrable timers also
need to be expired unconditional.

Fixes: 500462a9de ("timers: Switch to a non-cascading wheel")
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Cc: rt@linutronix.de
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Link: https://lkml.kernel.org/r/20171222145337.633328378@linutronix.de
2017-12-29 23:13:09 +01:00
Linus Torvalds 61233580f1 Merge tag 'pm-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fix from Rafael Wysocki:
 "This fixes a schedutil cpufreq governor regression from the 4.14 cycle
  that may cause a CPU idleness check to return incorrect results in
  some cases which leads to suboptimal decisions (Joel Fernandes)"

* tag 'pm-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: schedutil: Use idle_calls counter of the remote CPU
2017-12-29 11:54:15 -08:00
Linus Torvalds 2758b3e3e6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) IPv6 gre tunnels end up with different default features enabled
    depending upon whether netlink or ioctls are used to bring them up.
    Fix from Alexey Kodanev.

 2) Fix read past end of user control message in RDS< from Avinash
    Repaka.

 3) Missing RCU barrier in mini qdisc code, from Cong Wang.

 4) Missing policy put when reusing per-cpu route entries, from Florian
    Westphal.

 5) Handle nested PCI errors properly in bnx2x driver, from Guilherme G.
    Piccoli.

 6) Run nested transport mode IPSEC packets via tasklet, from Herbert
    Xu.

 7) Fix handling poll() for stream sockets in tipc, from Parthasarathy
    Bhuvaragan.

 8) Fix two stack-out-of-bounds issues in IPSEC, from Steffen Klassert.

 9) Another zerocopy ubuf handling fix, from Willem de Bruijn.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (33 commits)
  strparser: Call sock_owned_by_user_nocheck
  sock: Add sock_owned_by_user_nocheck
  skbuff: in skb_copy_ubufs unclone before releasing zerocopy
  tipc: fix hanging poll() for stream sockets
  sctp: Replace use of sockets_allocated with specified macro.
  bnx2x: Improve reliability in case of nested PCI errors
  tg3: Enable PHY reset in MTU change path for 5720
  tg3: Add workaround to restrict 5762 MRRS to 2048
  tg3: Update copyright
  net: fec: unmap the xmit buffer that are not transferred by DMA
  tipc: fix tipc_mon_delete() oops in tipc_enable_bearer() error path
  tipc: error path leak fixes in tipc_enable_bearer()
  RDS: Check cmsg_len before dereferencing CMSG_DATA
  tcp: Avoid preprocessor directives in tracepoint macro args
  tipc: fix memory leak of group member when peer node is lost
  net: sched: fix possible null pointer deref in tcf_block_put
  tipc: base group replicast ack counter on number of actual receivers
  net_sched: fix a missing rcu barrier in mini_qdisc_pair_swap()
  net: phy: micrel: ksz9031: reconfigure autoneg after phy autoneg workaround
  ip6_gre: fix device features for ioctl setup
  ...
2017-12-28 23:20:21 -08:00
Linus Torvalds fd84b751dd Merge tag 'drm-fixes-for-v4.15-rc6' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
 "nouveau and i915 regression fixes"

* tag 'drm-fixes-for-v4.15-rc6' of git://people.freedesktop.org/~airlied/linux:
  drm/nouveau: fix race when adding delayed work items
  i915: Reject CCS modifiers for pipe C on Geminilake
  drm/i915/gvt: Fix pipe A enable as default for vgpu
2017-12-28 23:16:24 -08:00
Linus Torvalds c0208a33cb Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk fix from Stephen Boyd:
 "One more fix for the runtime PM clk patches. We're calling a runtime
  PM API that may schedule from somewhere that we can't do that. We
  change to the async version of pm_runtime_put() to fix it"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: use atomic runtime pm api in clk_core_is_enabled
2017-12-28 23:14:47 -08:00
Linus Torvalds 4f2382f380 Merge tag 'led_fixes_for_4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds
Pull LED fix from Jacek Anaszewski:
 "A single LED fix for brightness setting when delay_off is 0"

* tag 'led_fixes_for_4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
  led: core: Fix brightness setting when setting delay_off=0
2017-12-28 23:09:45 -08:00
Linus Torvalds 19286e4a7a Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull rdma fixes from Jason Gunthorpe:
 "This is the next batch of for-rc patches from RDMA. It includes the
  fix for the ipoib regression I mentioned last time, and the result of
  a fairly major debugging effort to get iser working reliably on cxgb4
  hardware - it turns out the cxgb4 driver was not handling QP error
  flushing properly causing iser to fail.

   - cxgb4 fix for an iser testing failure as debugged by Steve and
     Sagi. The problem was a driver bug in the handling of shutting down
     a QP.

   - Various vmw_pvrdma fixes for bogus WARN_ON, missed resource free on
     error unwind and a use after free bug

   - Improper congestion counter values on mlx5 when link aggregation is
     enabled

   - ipoib lockdep regression introduced in this merge window

   - hfi1 regression supporting the device in a VM introduced in a
     recent patch

   - Typo that breaks future uAPI compatibility in the verbs core

   - More SELinux related oops fixing

   - Fix an oops during error unwind in mlx5"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
  IB/mlx5: Fix mlx5_ib_alloc_mr error flow
  IB/core: Verify that QP is security enabled in create and destroy
  IB/uverbs: Fix command checking as part of ib_uverbs_ex_modify_qp()
  IB/mlx5: Serialize access to the VMA list
  IB/hfi: Only read capability registers if the capability exists
  IB/ipoib: Fix lockdep issue found on ipoib_ib_dev_heavy_flush
  IB/mlx5: Fix congestion counters in LAG mode
  RDMA/vmw_pvrdma: Avoid use after free due to QP/CQ/SRQ destroy
  RDMA/vmw_pvrdma: Use refcount_dec_and_test to avoid warning
  RDMA/vmw_pvrdma: Call ib_umem_release on destroy QP path
  iw_cxgb4: when flushing, complete all wrs in a chain
  iw_cxgb4: reflect the original WR opcode in drain cqes
  iw_cxgb4: Only validate the MSN for successful completions
2017-12-28 23:06:01 -08:00
David S. Miller d5902f6d1f Merge branch 'strparser-Fix-lockdep-issue'
Tom Herbert says:

====================
strparser: Fix lockdep issue

When sock_owned_by_user returns true in strparser. Fix is to add and
call sock_owned_by_user_nocheck since the check for owned by user is
not an error condition in this case.
====================

Fixes: 43a0c6751a ("strparser: Stream parser for messages")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-and-tested-by: <syzbot+c91c53af67f9ebe599a337d2e70950366153b295@syzkaller.appspotmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-28 14:28:23 -05:00
Tom Herbert d66fa9ec53 strparser: Call sock_owned_by_user_nocheck
strparser wants to check socket ownership without producing any
warnings. As indicated by the comment in the code, it is permissible
for owned_by_user to return true.

Fixes: 43a0c6751a ("strparser: Stream parser for messages")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-and-tested-by: <syzbot+c91c53af67f9ebe599a337d2e70950366153b295@syzkaller.appspotmail.com>
Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-28 14:28:22 -05:00
Tom Herbert 602f7a2714 sock: Add sock_owned_by_user_nocheck
This allows checking socket lock ownership with producing lockdep
warnings.

Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-28 14:28:22 -05:00
Willem de Bruijn f72c4ac695 skbuff: in skb_copy_ubufs unclone before releasing zerocopy
skb_copy_ubufs must unclone before it is safe to modify its
skb_shared_info with skb_zcopy_clear.

Commit b90ddd5687 ("skbuff: skb_copy_ubufs must release uarg even
without user frags") ensures that all skbs release their zerocopy
state, even those without frags.

But I forgot an edge case where such an skb arrives that is cloned.

The stack does not build such packets. Vhost/tun skbs have their
frags orphaned before cloning. TCP skbs only attach zerocopy state
when a frag is added.

But if TCP packets can be trimmed or linearized, this might occur.
Tracing the code I found no instance so far (e.g., skb_linearize
ends up calling skb_zcopy_clear if !skb->data_len).

Still, it is non-obvious that no path exists. And it is fragile to
rely on this.

Fixes: b90ddd5687 ("skbuff: skb_copy_ubufs must release uarg even without user frags")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-28 14:26:22 -05:00
Parthasarathy Bhuvaragan 517d7c79bd tipc: fix hanging poll() for stream sockets
In commit 42b531de17 ("tipc: Fix missing connection request
handling"), we replaced unconditional wakeup() with condtional
wakeup for clients with flags POLLIN | POLLRDNORM | POLLRDBAND.

This breaks the applications which do a connect followed by poll
with POLLOUT flag. These applications are not woken when the
connection is ESTABLISHED and hence sleep forever.

In this commit, we fix it by including the POLLOUT event for
sockets in TIPC_CONNECTING state.

Fixes: 42b531de17 ("tipc: Fix missing connection request handling")
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-28 12:15:26 -05:00
Joel Fernandes 466a2b42d6 cpufreq: schedutil: Use idle_calls counter of the remote CPU
Since the recent remote cpufreq callback work, its possible that a cpufreq
update is triggered from a remote CPU. For single policies however, the current
code uses the local CPU when trying to determine if the remote sg_cpu entered
idle or is busy. This is incorrect. To remedy this, compare with the nohz tick
idle_calls counter of the remote CPU.

Fixes: 674e75411f (sched: cpufreq: Allow remote cpufreq callbacks)
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Cc: 4.14+ <stable@vger.kernel.org> # 4.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-12-28 12:26:54 +01:00
David S. Miller 1528f6e276 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2017-12-28

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Two small fixes for bpftool. Fix otherwise broken output if any of
   the system calls failed when listing maps in json format and instead
   of bailing out, skip maps or progs that disappeared between fetching
   next id and getting an fd for that id, both from Jakub.

2) Small fix in BPF selftests to respect LLC passed from command line
   when testing for -mcpu=probe presence, from Quentin.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-27 20:35:03 -05:00
Nitzan Carmi 45e6ae7ef2 IB/mlx5: Fix mlx5_ib_alloc_mr error flow
ibmr.device is being set only after ib_alloc_mr() is
(successfully) complete. Therefore, in case mlx5_core_create_mkey()
return with error, the error flow calls mlx5_free_priv_descs()
which uses ibmr.device (which doesn't exist yet), causing
a NULL dereference oops.

To fix this, the IB device should be set in the mr struct earlier
stage (e.g. prior to calling mlx5_core_create_mkey()).

Fixes: 8a187ee52b ("IB/mlx5: Support the new memory registration API")
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Nitzan Carmi <nitzanc@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2017-12-27 15:24:41 -07:00
Moni Shoua 4a50881bba IB/core: Verify that QP is security enabled in create and destroy
The XRC target QP create flow sets up qp_sec only if there is an IB link with
LSM security enabled. However, several other related uAPI entry points blindly
follow the qp_sec NULL pointer, resulting in a possible oops.

Check for NULL before using qp_sec.

Cc: <stable@vger.kernel.org> # v4.12
Fixes: d291f1a652 ("IB/core: Enforce PKey security on QPs")
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2017-12-27 15:24:41 -07:00
Moni Shoua 05d14e7b0c IB/uverbs: Fix command checking as part of ib_uverbs_ex_modify_qp()
If the input command length is larger than the kernel supports an error should
be returned in case the unsupported bytes are not cleared, instead of the
other way aroudn. This matches what all other callers of ib_is_udata_cleared
do and will avoid user ABI problems in the future.

Cc: <stable@vger.kernel.org> # v4.10
Fixes: 189aba99e7 ("IB/uverbs: Extend modify_qp and support packet pacing")
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2017-12-27 15:24:41 -07:00
Majd Dibbiny ad9a3668a4 IB/mlx5: Serialize access to the VMA list
User-space applications can do mmap and munmap directly at
any time.

Since the VMA list is not protected with a mutex, concurrent
accesses to the VMA list from the mmap and munmap can cause
data corruption. Add a mutex around the list.

Cc: <stable@vger.kernel.org> # v4.7
Fixes: 7c2344c3bb ("IB/mlx5: Implements disassociate_ucontext API")
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2017-12-27 15:24:40 -07:00
Linus Torvalds 5f520fc318 Merge tag 'trace-v4.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
 "While doing tests on tracing over the network, I found that the
  packets were getting corrupted.

  In the process I found three bugs.

  One was the culprit, but the other two scared me. After deeper
  investigation, they were not as major as I thought they were, due to a
  signed compared to an unsigned that prevented a negative number from
  doing actual harm.

  The two bigger bugs:

   - Mask the ring buffer data page length. There are data flags at the
     high bits of the length field. These were not cleared via the
     length function, and the length could return a negative number.
     (Although the number returned was unsigned, but was assigned to a
     signed number) Luckily, this value was compared to PAGE_SIZE which
     is unsigned and kept it from entering the path that could have
     caused damage.

   - Check the page usage before reusing the ring buffer reader page.
     TCP increments the page ref when passing the page off to the
     network. The page is passed back to the ring buffer for use on
     free. But the page could still be in use by the TCP stack.

  Minor bugs:

   - Related to the first bug. No need to clear out the unused ring
     buffer data before sending to user space. It is now done by the
     ring buffer code itself.

   - Reset pointers after free on error path. There were some cases in
     the error path that pointers were freed but not set to NULL, and
     could have them freed again, having a pointer freed twice"

* tag 'trace-v4.15-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix possible double free on failure of allocating trace buffer
  tracing: Fix crash when it fails to alloc ring buffer
  ring-buffer: Do no reuse reader page if still in use
  tracing: Remove extra zeroing out of the ring buffer page
  ring-buffer: Mask out the info bits when returning buffer page length
2017-12-27 13:06:57 -08:00
Linus Torvalds 9b9577948f Merge tag 'sound-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
 "It seems that Santa overslept with a bunch of gifts; the majority of
  changes here are various device-specific ASoC fixes, most notably the
  revert of rcar IOMMU support and fsl_ssi AC97 fixes, but also lots of
  small fixes for codecs. Besides that, the usual HD-audio quirks and
  fixes are included, too"

* tag 'sound-4.15-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (31 commits)
  ALSA: hda - Fix missing COEF init for ALC225/295/299
  ALSA: hda: Drop useless WARN_ON()
  ALSA: hda - change the location for one mic on a Lenovo machine
  ALSA: hda - fix headset mic detection issue on a Dell machine
  ALSA: hda - Add MIC_NO_PRESENCE fixup for 2 HP machines
  ASoC: rsnd: fixup ADG register mask
  ASoC: rt5514-spi: only enable wakeup when fully initialized
  ASoC: nau8825: fix issue that pop noise when start capture
  ASoC: rt5663: Fix the wrong result of the first jack detection
  ASoC: rsnd: ssi: fix race condition in rsnd_ssi_pointer_update
  ASoC: Intel: Change kern log level to avoid unwanted messages
  ASoC: atmel-classd: select correct Kconfig symbol
  ASoC: wm_adsp: Fix validation of firmware and coeff lengths
  ASoC: Intel: Skylake: Do not check dev_type for dmic link type
  ASoC: rockchip: disable clock on error
  ASoC: tlv320aic31xx: Fix GPIO1 register definition
  ASoC: codecs: msm8916-wcd: Fix supported formats
  ASoC: fsl_asrc: Fix typo in a field define
  ASoC: rsnd: ssiu: clear SSI_MODE for non TDM Extended modes
  ASoC: da7218: Correct IRQ level in DT binding example
  ...
2017-12-27 12:59:27 -08:00
Matthieu CASTET 2b83ff96f5 led: core: Fix brightness setting when setting delay_off=0
With the current code, the following sequence won't work :
echo timer > trigger

echo 0 >  delay_off
* at this point we call
** led_delay_off_store
** led_blink_set
*** stop timer
** led_blink_setup
** led_set_software_blink
*** if !delay_on, led off
*** if !delay_off, set led_set_brightness_nosleep <--- LED_BLINK_SW is set but timer is stop
*** otherwise start timer/set LED_BLINK_SW flag

echo xxx > brightness
* led_set_brightness
** if LED_BLINK_SW
*** if brightness=0, led off
*** else apply brightness if next timer <--- timer is stop, and will never apply new setting
** otherwise set led_set_brightness_nosleep

To fix that, when we delete the timer, we should clear LED_BLINK_SW.

Cc: linux-leds@vger.kernel.org
Signed-off-by: Matthieu CASTET <matthieu.castet@parrot.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
2017-12-27 20:45:07 +01:00
Steven Rostedt (VMware) 4397f04575 tracing: Fix possible double free on failure of allocating trace buffer
Jing Xia and Chunyan Zhang reported that on failing to allocate part of the
tracing buffer, memory is freed, but the pointers that point to them are not
initialized back to NULL, and later paths may try to free the freed memory
again. Jing and Chunyan fixed one of the locations that does this, but
missed a spot.

Link: http://lkml.kernel.org/r/20171226071253.8968-1-chunyan.zhang@spreadtrum.com

Cc: stable@vger.kernel.org
Fixes: 737223fbca ("tracing: Consolidate buffer allocation code")
Reported-by: Jing Xia <jing.xia@spreadtrum.com>
Reported-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-12-27 14:21:27 -05:00
Jing Xia 24f2aaf952 tracing: Fix crash when it fails to alloc ring buffer
Double free of the ring buffer happens when it fails to alloc new
ring buffer instance for max_buffer if TRACER_MAX_TRACE is configured.
The root cause is that the pointer is not set to NULL after the buffer
is freed in allocate_trace_buffers(), and the freeing of the ring
buffer is invoked again later if the pointer is not equal to Null,
as:

instance_mkdir()
    |-allocate_trace_buffers()
        |-allocate_trace_buffer(tr, &tr->trace_buffer...)
	|-allocate_trace_buffer(tr, &tr->max_buffer...)

          // allocate fail(-ENOMEM),first free
          // and the buffer pointer is not set to null
        |-ring_buffer_free(tr->trace_buffer.buffer)

       // out_free_tr
    |-free_trace_buffers()
        |-free_trace_buffer(&tr->trace_buffer);

	      //if trace_buffer is not null, free again
	    |-ring_buffer_free(buf->buffer)
                |-rb_free_cpu_buffer(buffer->buffers[cpu])
                    // ring_buffer_per_cpu is null, and
                    // crash in ring_buffer_per_cpu->pages

Link: http://lkml.kernel.org/r/20171226071253.8968-1-chunyan.zhang@spreadtrum.com

Cc: stable@vger.kernel.org
Fixes: 737223fbca ("tracing: Consolidate buffer allocation code")
Signed-off-by: Jing Xia <jing.xia@spreadtrum.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-12-27 14:21:16 -05:00