commit 34ffb33e09 upstream.
The 'ni_at_a2150' module links to `cfc_write_to_buffer` in the
'comedi_fc' module, so selecting 'COMEDI_NI_AT_A2150' in the kernel config
needs to also select 'COMEDI_FC'.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c43435d772 upstream.
comedi_auto_config() associates a Comedi minor device number with an
auto-configured hardware device and comedi_auto_unconfig() disassociates
it. Currently, these use the hardware device's private data pointer to
point to some allocated storage holding the minor device number. This
is a bit of a waste of the hardware device's private data pointer,
preventing it from being used for something more useful by the low-level
comedi device drivers. For example, it would make more sense if
comedi_usb_auto_config() was passed a pointer to the struct
usb_interface instead of the struct usb_device, but this cannot be done
currently because the low-level comedi drivers already use the private
data pointer in the struct usb_interface for something more useful.
This patch stops the comedi core hijacking the hardware device's private
data pointer. Instead, comedi_auto_config() stores a pointer to the
hardware device's struct device in the struct comedi_device_file_info
associated with the minor device number, and comedi_auto_unconfig()
calls new function comedi_find_board_minor() to recover the minor device
number associated with the hardware device.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e43a028752 upstream.
When remembering the direction of a DCR transaction, we should write
to the same variable that we interpret on later when doing vcpu_run
again.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6491d4d028 upstream.
The dma_pte_free_pagetable() function will only free a page table page
if it is asked to free the *entire* 2MiB range that it covers. So if a
page table page was used for one or more small mappings, it's likely to
end up still present in the page tables... but with no valid PTEs.
This was fine when we'd only be repopulating it with 4KiB PTEs anyway
but the same virtual address range can end up being reused for a
*large-page* mapping. And in that case were were trying to insert the
large page into the second-level page table, and getting a complaint
from the sanity check in __domain_mapping() because there was already a
corresponding entry. This was *relatively* harmless; it led to a memory
leak of the old page table page, but no other ill-effects.
Fix it by calling dma_pte_clear_range (hopefully redundant) and
dma_pte_free_pagetable() before setting up the new large page.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Tested-by: Ravi Murty <Ravi.Murty@intel.com>
Tested-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 96e5d1d3ad upstream.
In gfs2_trans_add_bh(), gfs2 was testing if a there was a bd attached to the
buffer without having the gfs2_log_lock held. It was then assuming it would
stay attached for the rest of the function. However, without either the log
lock being held of the buffer locked, __gfs2_ail_flush() could detach bd at any
time. This patch moves the locking before the test. If there isn't a bd
already attached, gfs2 can safely allocate one and attach it before locking.
There is no way that the newly allocated bd could be on the ail list,
and thus no way for __gfs2_ail_flush() to detach it.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 55c1945eda upstream.
A high speed control or bulk endpoint may have bInterval set to zero,
which means it does not NAK. If bInterval is non-zero, it means the
endpoint NAKs at a rate of 2^(bInterval - 1).
The xHCI code to compute the NAK interval does not handle the special
case of zero properly. The current code unconditionally subtracts one
from bInterval and uses it as an exponent. This causes a very large
bInterval to be used, and warning messages like these will be printed:
usb 1-1: ep 0x1 - rounding interval to 32768 microframes, ep desc says 0 microframes
This may cause the xHCI host hardware to reject the Configure Endpoint
command, which means the HS device will be unusable under xHCI ports.
This patch should be backported to kernels as old as 2.6.31, that contain
commit dfa49c4ad1 "USB: xhci - fix math in
xhci_get_endpoint_interval()".
Reported-by: Vincent Pelletier <plr.vincent@gmail.com>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 07e72b95f5 upstream.
Some touchscreens have buggy firmware which claims
remote wakeup to be enabled after a reset. They nevertheless
crash if the feature is cleared by the host.
Add a check for reset resume before checking for
an enabled remote wakeup feature. On compliant
devices the feature must be cleared after a reset anyway.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 77c7f072c8 upstream.
John's NEC 0.96 xHCI host controller needs a longer timeout for a warm
reset to complete. The logs show it takes 650ms to complete the warm
reset, so extend the hub reset timeout to 800ms to be on the safe side.
This commit should be backported to kernels as old as 3.2, that contain
the commit 75d7cf72ab "usbcore: refine
warm reset logic".
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: John Covici <covici@ccs.covici.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1d16638e3b upstream.
If we do have endpoints named like "ep-a" then bEndpointAddress is
counted internally by the gadget framework.
If we do have endpoints named like "ep-1" then bEndpointAddress is
assigned from the digit after "ep-".
If we do have both, then it is likely that after we used up the
"generic" endpoints we will use the digits and thus assign one
bEndpointAddress to multiple endpoints.
This theory can be proofed by using the completely enabled g_multi.
Without this patch, the mass storage won't enumerate and times out
because it shares endpoints with RNDIS.
This patch also adds fills up the endpoints list so we have in total
endpoints 1 to 15 in + out available while some of them are restricted
to certain types like BULK or ISO. Without this change the nokia gadget
won't load because the system does not provide enough (BULK) endpoints
but it did before ep-a - ep-f were removed.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 036915a7a4 upstream.
Adding support "PSC Scanning, Magellan 800i" in cdc-acm
Very simple, but very necessary.
Suitable for all versions of the kernel > 2.6
Signed-off-by: Denis N Ladin <denladin@gmail.com>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8cf65dc386 upstream.
Simple fix to add support for Crucible Technologies COMET Caller ID
USB decoder - a device containing FTDI USB/Serial converter chip,
handling 1200bps CallerID messages decoded from the phone line -
adding correct USB PID is sufficient.
Tested to apply cleanly and work flawlessly against 3.6.9, 3.7.0-rc8
and 3.8.0-rc3 on both amd64 and x86 arches.
Signed-off-by: Tomasz Mloduchowski <q@qdot.me>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5ec0085440 upstream.
also known as Alcatel One Touch L100V LTE
The driver description files gives these names to the vendor specific
functions on this modem:
Application1: VID_1BBB&PID_011E&MI_00
Application2: VID_1BBB&PID_011E&MI_01
Modem: VID_1BBB&PID_011E&MI_03
Ethernet: VID_1BBB&PID_011E&MI_04
Reported-by: Thomas Schäfer <tschaefer@t-online.de>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 94a85b6338 upstream.
In option.c, add some new MEDIATEK PIDs support for MEDIATEK new products. This
is a MEDIATEK inc. release patch.
Signed-off-by: Quentin.Li <snowmanli88@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a56f992cda upstream.
This is a very old bug, but there's nothing that prevents the
timer from running while the module is being removed when we
only do del_timer() instead of del_timer_sync().
The timer should normally not be running at this point, but
it's not clearly impossible (or we could just remove this.)
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 51861d4eeb upstream.
Those rn50 chip are often connected to console remoting hw and load
detection often fails with those. Just don't try to load detect and
report connect.
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c0729eeefd upstream.
Éric Piel reported a kernel oops in the "comedi_test" module. It was a
NULL pointer dereference within `waveform_ai_interrupt()` (actually a
timer function) that sometimes occurred when a running asynchronous
command is cancelled (either by the `COMEDI_CANCEL` ioctl or by closing
the device file).
This seems to be a race between the caller of `waveform_ai_cancel()`
which on return from that function goes and tears down the running
command, and the timer function which uses the command. In particular,
`async->cmd.chanlist` gets freed (and the pointer set to NULL) by
`do_become_nonbusy()` in "comedi_fops.c" but a previously scheduled
`waveform_ai_interrupt()` timer function will dereference that pointer
regardless, leading to the oops.
Fix it by replacing the `del_timer()` call in `waveform_ai_cancel()`
with `del_timer_sync()`.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reported-by: Éric Piel <piel@delmic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7d3135af39 upstream.
When a low-level comedi driver auto-configures a device, a `struct
comedi_dev_file_info` is allocated (as well as a `struct
comedi_device`) by `comedi_alloc_board_minor()`. A pointer to the
hardware `struct device` is stored as a cookie in the `struct
comedi_dev_file_info`. When the low-level comedi driver
auto-unconfigures the device, `comedi_auto_unconfig()` uses the cookie
to find the `struct comedi_dev_file_info` so it can detach the comedi
device from the driver, clean it up and free it.
A problem arises if the user manually unconfigures and reconfigures the
comedi device using the `COMEDI_DEVCONFIG` ioctl so that is no longer
associated with the original hardware device. The problem is that the
cookie is not cleared, so that a call to `comedi_auto_unconfig()` from
the low-level driver will still find it, detach it, clean it up and free
it.
Stop this problem occurring by always clearing the `hardware_device`
cookie in the `struct comedi_dev_file_info` whenever the
`COMEDI_DEVCONFIG` ioctl call is successful.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 41b645c862 upstream.
Cold reset on the pxa27x currently fails and
pxa2xx_ac97_try_cold_reset: cold reset timeout (GSR=0x44)
appears in the kernel log. Through trial-and-error (the pxa270 developer's
manual is mostly incoherent on the topic of ac97 reset), I got cold reset to
complete by setting the WARM_RST bit in the GCR register (and later noticed that
pxa3xx does this for cold reset as well). Also, a timeout loop is needed to
wait for the reset to complete.
Tested on a palm treo 680 machine.
Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 115c9b8192 upstream.
Implement a new netlink attribute type IFLA_EXT_MASK. The mask
is a 32 bit value that can be used to indicate to the kernel that
certain extended ifinfo values are requested by the user application.
At this time the only mask value defined is RTEXT_FILTER_VF to
indicate that the user wants the ifinfo dump to send information
about the VFs belonging to the interface.
This patch fixes a bug in which certain applications do not have
large enough buffers to accommodate the extra information returned
by the kernel with large numbers of SR-IOV virtual functions.
Those applications will not send the new netlink attribute with
the interface info dump request netlink messages so they will
not get unexpectedly large request buffers returned by the kernel.
Modifies the rtnl_calcit function to traverse the list of net
devices and compute the minimum buffer size that can hold the
info dumps of all matching devices based upon the filter passed
in via the new netlink attribute filter mask. If no filter
mask is sent then the buffer allocation defaults to NLMSG_GOODSIZE.
With this change it is possible to add yet to be defined netlink
attributes to the dump request which should make it fairly extensible
in the future.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Acked-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.0:
- Adjust context
- Drop the change in do_setlink() that reverts commit f18da14565
('net: RTNETLINK adjusting values of min_ifinfo_dump_size'), which
was never applied here]
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c7ac8679be upstream.
The message size allocated for rtnl ifinfo dumps was limited to
a single page. This is not enough for additional interface info
available with devices that support SR-IOV and caused a bug in
which VF info would not be displayed if more than approximately
40 VFs were created per interface.
Implement a new function pointer for the rtnl_register service that will
calculate the amount of data required for the ifinfo dump and allocate
enough data to satisfy the request.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2bbf0a1427 upstream.
The Way Access Filter in recent AMD CPUs may hurt the performance of
some workloads, caused by aliasing issues in the L1 cache.
This patch disables it on the affected CPUs.
The issue is similar to that one of last year:
http://lkml.indiana.edu/hypermail/linux/kernel/1107.3/00041.html
This new patch does not replace the old one, we just need another
quirk for newer CPUs.
The performance penalty without the patch depends on the
circumstances, but is a bit less than the last year's 3%.
The workloads affected would be those that access code from the same
physical page under different virtual addresses, so different
processes using the same libraries with ASLR or multiple instances of
PIE-binaries. The code needs to be accessed simultaneously from both
cores of the same compute unit.
More details can be found here:
http://developer.amd.com/Assets/SharedL1InstructionCacheonAMD15hCPU.pdf
CPUs affected are anything with the core known as Piledriver.
That includes the new parts of the AMD A-Series (aka Trinity) and the
just released new CPUs of the FX-Series (aka Vishera).
The model numbering is a bit odd here: FX CPUs have model 2,
A-Series has model 10h, with possible extensions to 1Fh. Hence the
range of model ids.
Signed-off-by: Andre Przywara <osp@andrep.de>
Link: http://lkml.kernel.org/r/1351700450-9277-1-git-send-email-osp@andrep.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1f1d06c34f upstream.
On COW, a new hugepage is allocated and charged to the memcg. If the
system is oom or the charge to the memcg fails, however, the fault
handler will return VM_FAULT_OOM which results in an oom kill.
Instead, it's possible to fallback to splitting the hugepage so that the
COW results only in an order-0 page being allocated and charged to the
memcg which has a higher liklihood to succeed. This is expensive
because the hugepage must be split in the page fault handler, but it is
much better than unnecessarily oom killing a process.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fb719c59bd upstream.
Incrementing lenExtents even while writing to a hole is bad
for performance as calls to udf_discard_prealloc and
udf_truncate_tail_extent would not return from start if
isize != lenExtents
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Shuah Khan <shuah.khan@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0a41409c51 upstream, but doesn't
apply, so this version is different for older kernels than 3.7.x
blk_alloc_queue has already done a bdi_init, so do not bdi_init
again in aoeblk_gdalloc. The extra call causes list corruption
in the per-CPU backing dev info stats lists.
Affected users see console WARNINGs about list_del corruption on
percpu_counter_destroy when doing "rmmod aoe" or "aoeflush -a"
when AoE targets have been detected and initialized by the
system.
The patch below applies to v3.6.11, with its v47 aoe driver. It
is expected to apply to all currently maintained stable kernels
except 3.7.y. A related but different fix has been posted for
3.7.y.
References:
RedHat bugzilla ticket with original report
https://bugzilla.redhat.com/show_bug.cgi?id=853064
LKML discussion of bug and fix
http://thread.gmane.org/gmane.linux.kernel/1416336/focus=1416497
Reported-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 721e3eba21 upstream.
Commit c278531d39 added a warning when ext4_flush_unwritten_io() is
called without i_mutex being taken. It had previously not been taken
during orphan cleanup since races weren't possible at that point in
the mount process, but as a result of this c278531d39, we will now see
a kernel WARN_ON in this case. Take the i_mutex in
ext4_orphan_cleanup() to suppress this warning.
Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d096ad0f79 upstream.
When a journal-less ext4 filesystem is mounted on a read-only block
device (blockdev --setro will do), each remount (for other, unrelated,
flags, like suid=>nosuid etc) results in a series of scary messages
from kernel telling about I/O errors on the device.
This is becauese of the following code ext4_remount():
if (sbi->s_journal == NULL)
ext4_commit_super(sb, 1);
at the end of remount procedure, which forces writing (flushing) of
a superblock regardless whenever it is dirty or not, if the filesystem
is readonly or not, and whenever the device itself is readonly or not.
We only need call ext4_commit_super when the file system had been
previously mounted read/write.
Thanks to Eric Sandeen for help in diagnosing this issue.
Signed-off-By: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d7961c7fa4 upstream.
The following race is possible between start_this_handle() and someone
calling jbd2_journal_flush().
Process A Process B
start_this_handle().
if (journal->j_barrier_count) # false
if (!journal->j_running_transaction) { #true
read_unlock(&journal->j_state_lock);
jbd2_journal_lock_updates()
jbd2_journal_flush()
write_lock(&journal->j_state_lock);
if (journal->j_running_transaction) {
# false
... wait for committing trans ...
write_unlock(&journal->j_state_lock);
...
write_lock(&journal->j_state_lock);
if (!journal->j_running_transaction) { # true
jbd2_get_transaction(journal, new_transaction);
write_unlock(&journal->j_state_lock);
goto repeat; # eventually blocks on j_barrier_count > 0
...
J_ASSERT(!journal->j_running_transaction);
# fails
We fix the race by rechecking j_barrier_count after reacquiring j_state_lock
in exclusive mode.
Reported-by: yjwsignal@empal.com
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6c1ecba8d8 upstream.
The VDCTRL4 register does not provide the MXS SET/CLR/TOGGLE feature.
The write in mxsfb_disable_controller() sets the data_cnt for the LCD
DMA to 0 which obviously means the max. count for the LCD DMA and
leads to overwriting arbitrary memory when the display is unblanked.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Acked-by: Juergen Beisert <jbe@pengutronix.de>
Tested-by: Lauri Hintsala <lauri.hintsala@bluegiga.net>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 70e227790d upstream.
The timer appears to run too fast/race on 64 bit systems.
Using msecs_to_jiffies seems to cause a deadlock on 64 bit.
A calculation of (MSecond * HZ) / 1000 appears to run satisfactory.
Change BSSIDInfoCount to u32.
After this patch the driver can be successfully connect on little endian 64/32 bit systems.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7730492855 upstream.
After this patch all BYTE/WORD/DWORD types can be replaced with the appropriate u sizes.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ab1dd99631 upstream.
Calling RFbSetPower with uCH zero value will cause out of bound array reference.
This causes 64 bit kernels to oops on boot.
Note: Driver does not function on 64 bit kernels and should be
blacklisted on them.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e910d7ebec upstream.
Abort dm ioctl processing if userspace changes the data_size parameter
after we validated it but before we finished copying the data buffer
from userspace.
The dm ioctl parameters are processed in the following sequence:
1. ctl_ioctl() calls copy_params();
2. copy_params() makes a first copy of the fixed-sized portion of the
userspace parameters into the local variable "tmp";
3. copy_params() then validates tmp.data_size and allocates a new
structure big enough to hold the complete data and copies the whole
userspace buffer there;
4. ctl_ioctl() reads userspace data the second time and copies the whole
buffer into the pointer "param";
5. ctl_ioctl() reads param->data_size without any validation and stores it
in the variable "input_param_size";
6. "input_param_size" is further used as the authoritative size of the
kernel buffer.
The problem is that userspace code could change the contents of user
memory between steps 2 and 4. In particular, the data_size parameter
can be changed to an invalid value after the kernel has validated it.
This lets userspace force the kernel to access invalid kernel memory.
The fix is to ensure that the size has not changed at step 4.
This patch shouldn't have a security impact because CAP_SYS_ADMIN is
required to run this code, but it should be fixed anyway.
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9366c1ba13 upstream.
The function rb_check_pages() was added to make sure the ring buffer's
pages were sane. This check is done when the ring buffer size is modified
as well as when the iterator is released (closing the "trace" file),
as that was considered a non fast path and a good place to do a sanity
check.
The problem is that the check does not have any locks around it.
If one process were to read the trace file, and another were to read
the raw binary file, the check could happen while the reader is reading
the file.
The issues with this is that the check requires to clear the HEAD page
before doing the full check and it restores it afterward. But readers
require the HEAD page to exist before it can read the buffer, otherwise
it gives a nasty warning and disables the buffer.
By adding the reader lock around the check, this keeps the race from
happening.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
