linux-stable.git/kernel, branch v5.5.7

dma-direct: relax addressability checks in dma_direct_supported

2020-02-28T16:23:44+00:00

commit 91ef26f914171cf753330f13724fd9142b5b1640 upstream.

dma_direct_supported tries to find the minimum addressable bitmask
based on the end pfn and optional magic that architectures can use
to communicate the size of the magic ZONE_DMA that can be used
for bounce buffering.  But between the DMA offsets that can change
per device (or sometimes even region), the fact the ZONE_DMA isn't
even guaranteed to be the lowest addresses and failure of having
proper interfaces to the MM code this fails at least for one
arm subarchitecture.

As all the legacy DMA implementations have supported 32-bit DMA
masks, and 32-bit masks are guranteed to always work by the API
contract (using bounce buffers if needed), we can short cut the
complicated check and always return true without breaking existing
assumptions.  Hopefully we can properly clean up the interaction
with the arch defined zones and the bootmem allocator eventually.

Fixes: ad3c7b18c5b3 ("arm: use swiotlb for bounce buffering on LPAE configs")
Reported-by: Peter Ujfalusi 
Signed-off-by: Christoph Hellwig 
Tested-by: Peter Ujfalusi 
Signed-off-by: Greg Kroah-Hartman

bpf, offload: Replace bitwise AND by logical AND in bpf_prog_offload_info_fill

2020-02-28T16:23:43+00:00

commit e20d3a055a457a10a4c748ce5b7c2ed3173a1324 upstream.

This if guards whether user-space wants a copy of the offload-jited
bytecode and whether this bytecode exists. By erroneously doing a bitwise
AND instead of a logical AND on user- and kernel-space buffer-size can lead
to no data being copied to user-space especially when user-space size is a
power of two and bigger then the kernel-space buffer.

Fixes: fcfb126defda ("bpf: add new jited info fields in bpf_dev_offload and bpf_prog_info")
Signed-off-by: Johannes Krude 
Signed-off-by: Daniel Borkmann 
Acked-by: Jakub Kicinski 
Link: https://lore.kernel.org/bpf/20200212193227.GA3769@phlox.h.transitiv.net
Signed-off-by: Greg Kroah-Hartman

genirq/proc: Reject invalid affinity masks (again)

2020-02-28T16:23:43+00:00

commit cba6437a1854fde5934098ec3bd0ee83af3129f5 upstream.

Qian Cai reported that the WARN_ON() in the x86/msi affinity setting code,
which catches cases where the affinity setting is not done on the CPU which
is the current target of the interrupt, triggers during CPU hotplug stress
testing.

It turns out that the warning which was added with the commit addressing
the MSI affinity race unearthed yet another long standing bug.

If user space writes a bogus affinity mask, i.e. it contains no online CPUs,
then it calls irq_select_affinity_usr(). This was introduced for ALPHA in

  eee45269b0f5 ("[PATCH] Alpha: convert to generic irq framework (generic part)")

and subsequently made available for all architectures in

  18404756765c ("genirq: Expose default irq affinity mask (take 3)")

which introduced the circumvention of the affinity setting restrictions for
interrupt which cannot be moved in process context.

The whole exercise is bogus in various aspects:

  1) If the interrupt is already started up then there is absolutely
     no point to honour a bogus interrupt affinity setting from user
     space. The interrupt is already assigned to an online CPU and it
     does not make any sense to reassign it to some other randomly
     chosen online CPU.

  2) If the interupt is not yet started up then there is no point
     either. A subsequent startup of the interrupt will invoke
     irq_setup_affinity() anyway which will chose a valid target CPU.

So the only correct solution is to just return -EINVAL in case user space
wrote an affinity mask which does not contain any online CPUs, except for
ALPHA which has it's own magic sauce for this.

Fixes: 18404756765c ("genirq: Expose default irq affinity mask (take 3)")
Reported-by: Qian Cai 
Signed-off-by: Thomas Gleixner 
Tested-by: Qian Cai 
Link: https://lkml.kernel.org/r/878sl8xdbm.fsf@nanos.tec.linutronix.de
Signed-off-by: Greg Kroah-Hartman

sched/psi: Fix OOB write when writing 0 bytes to PSI files

2020-02-28T16:23:38+00:00

commit 6fcca0fa48118e6d63733eb4644c6cd880c15b8f upstream.

Issuing write() with count parameter set to 0 on any file under
/proc/pressure/ will cause an OOB write because of the access to
buf[buf_size-1] when NUL-termination is performed. Fix this by checking
for buf_size to be non-zero.

Signed-off-by: Suren Baghdasaryan 
Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Acked-by: Johannes Weiner 
Link: https://lkml.kernel.org/r/20200203212216.7076-1-surenb@google.com
Signed-off-by: Greg Kroah-Hartman

tracing: Fix now invalid var_ref_vals assumption in trace action

2020-02-24T07:38:47+00:00

[ Upstream commit d380dcde9a07ca5de4805dee11f58a98ec0ad6ff ]

The patch 'tracing: Fix histogram code when expression has same var as
value' added code to return an existing variable reference when
creating a new variable reference, which resulted in var_ref_vals
slots being reused instead of being duplicated.

The implementation of the trace action assumes that the end of the
var_ref_vals array starting at action_data.var_ref_idx corresponds to
the values that will be assigned to the trace params. The patch
mentioned above invalidates that assumption, which means that each
param needs to explicitly specify its index into var_ref_vals.

This fix changes action_data.var_ref_idx to an array of var ref
indexes to account for that.

Link: https://lore.kernel.org/r/1580335695.6220.8.camel@kernel.org

Fixes: 8bcebc77e85f ("tracing: Fix histogram code when expression has same var as value")
Signed-off-by: Tom Zanussi 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Sasha Levin

trigger_next should increase position index

2020-02-24T07:38:46+00:00

[ Upstream commit 6722b23e7a2ace078344064a9735fb73e554e9ef ]

if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

Without patch:
 # dd bs=30 skip=1 if=/sys/kernel/tracing/events/sched/sched_switch/trigger
 dd: /sys/kernel/tracing/events/sched/sched_switch/trigger: cannot skip to specified offset
 n traceoff snapshot stacktrace enable_event disable_event enable_hist disable_hist hist
 # Available triggers:
 # traceon traceoff snapshot stacktrace enable_event disable_event enable_hist disable_hist hist
 6+1 records in
 6+1 records out
 206 bytes copied, 0.00027916 s, 738 kB/s

Notice the printing of "# Available triggers:..." after the line.

With the patch:
 # dd bs=30 skip=1 if=/sys/kernel/tracing/events/sched/sched_switch/trigger
 dd: /sys/kernel/tracing/events/sched/sched_switch/trigger: cannot skip to specified offset
 n traceoff snapshot stacktrace enable_event disable_event enable_hist disable_hist hist
 2+1 records in
 2+1 records out
 88 bytes copied, 0.000526867 s, 167 kB/s

It only prints the end of the file, and does not restart.

Link: http://lkml.kernel.org/r/3c35ee24-dd3a-8119-9c19-552ed253388a@virtuozzo.com

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Sasha Levin

ftrace: fpid_next() should increase position index

2020-02-24T07:38:46+00:00

[ Upstream commit e4075e8bdffd93a9b6d6e1d52fabedceeca5a91b ]

if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

Without patch:
 # dd bs=4 skip=1 if=/sys/kernel/tracing/set_ftrace_pid
 dd: /sys/kernel/tracing/set_ftrace_pid: cannot skip to specified offset
 id
 no pid
 2+1 records in
 2+1 records out
 10 bytes copied, 0.000213285 s, 46.9 kB/s

Notice the "id" followed by "no pid".

With the patch:
 # dd bs=4 skip=1 if=/sys/kernel/tracing/set_ftrace_pid
 dd: /sys/kernel/tracing/set_ftrace_pid: cannot skip to specified offset
 id
 0+1 records in
 0+1 records out
 3 bytes copied, 0.000202112 s, 14.8 kB/s

Notice that it only prints "id" and not the "no pid" afterward.

Link: http://lkml.kernel.org/r/4f87c6ad-f114-30bb-8506-c32274ce2992@virtuozzo.com

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Sasha Levin

bpf: map_seq_next should always increase position index

2020-02-24T07:38:44+00:00

[ Upstream commit 90435a7891a2259b0f74c5a1bc5600d0d64cba8f ]

If seq_file .next fuction does not change position index,
read after some lseek can generate an unexpected output.

See also: https://bugzilla.kernel.org/show_bug.cgi?id=206283

v1 -> v2: removed missed increment in end of function

Signed-off-by: Vasily Averin 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/eca84fdd-c374-a154-d874-6c7b55fc3bc4@virtuozzo.com
Signed-off-by: Sasha Levin

alarmtimer: Make alarmtimer platform device child of RTC device

2020-02-24T07:38:42+00:00

[ Upstream commit c79108bd19a8490315847e0c95ac6526fcd8e770 ]

The alarmtimer_suspend() function will fail if an RTC device is on a bus
such as SPI or i2c and that RTC device registers and probes after
alarmtimer_init() registers and probes the 'alarmtimer' platform device.

This is because system wide suspend suspends devices in the reverse order
of their probe. When alarmtimer_suspend() attempts to program the RTC for a
wakeup it will try to program an RTC device on a bus that has already been
suspended.

Move the alarmtimer device registration to happen when the RTC which is
used for wakeup is registered. Register the 'alarmtimer' platform device as
a child of the RTC device too, so that it can be guaranteed that the RTC
device won't be suspended when alarmtimer_suspend() is called.

Reported-by: Douglas Anderson 
Signed-off-by: Stephen Boyd 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Douglas Anderson 
Link: https://lore.kernel.org/r/20200124055849.154411-2-swboyd@chromium.org
Signed-off-by: Sasha Levin

module: avoid setting info->name early in case we can fall back to info->mod->name

2020-02-24T07:38:38+00:00

[ Upstream commit 708e0ada1916be765b7faa58854062f2bc620bbf ]

In setup_load_info(), info->name (which contains the name of the module,
mostly used for early logging purposes before the module gets set up)
gets unconditionally assigned if .modinfo is missing despite the fact
that there is an if (!info->name) check near the end of the function.
Avoid assigning a placeholder string to info->name if .modinfo doesn't
exist, so that we can fall back to info->mod->name later on.

Fixes: 5fdc7db6448a ("module: setup load info before module_sig_check()")
Reviewed-by: Miroslav Benes 
Signed-off-by: Jessica Yu 
Signed-off-by: Sasha Levin