linux-stable.git/arch/x86/kernel/cpu/mcheck, branch linux-4.4.y

x86/mce/amd: Fix kobject lifetime

2020-02-28T14:39:13+00:00

commit 51dede9c05df2b78acd6dcf6a17d21f0877d2d7b upstream.

Accessing the MCA thresholding controls in sysfs concurrently with CPU
hotplug can lead to a couple of KASAN-reported issues:

  BUG: KASAN: use-after-free in sysfs_file_ops+0x155/0x180
  Read of size 8 at addr ffff888367578940 by task grep/4019

and

  BUG: KASAN: use-after-free in show_error_count+0x15c/0x180
  Read of size 2 at addr ffff888368a05514 by task grep/4454

for example. Both result from the fact that the threshold block
creation/teardown code frees the descriptor memory itself instead of
defining proper ->release function and leaving it to the driver core to
take care of that, after all sysfs accesses have completed.

Do that and get rid of the custom freeing code, fixing the above UAFs in
the process.

  [ bp: write commit message. ]

Fixes: 95268664390b ("[PATCH] x86_64: mce_amd support for family 0x10 processors")
Signed-off-by: Thomas Gleixner 
Signed-off-by: Borislav Petkov 
Cc: 
Link: https://lkml.kernel.org/r/20200214082801.13836-1-bp@alien8.de
Signed-off-by: Greg Kroah-Hartman

x86/MCE/AMD: Turn off MC4_MISC thresholding on all family 0x15 models

2019-12-21T09:35:33+00:00

[ Upstream commit c95b323dcd3598dd7ef5005d6723c1ba3b801093 ]

MC4_MISC thresholding is not supported on all family 0x15 processors,
hence skip the x86_model check when applying the quirk.

 [ bp: massage commit message. ]

Signed-off-by: Shirish S 
Signed-off-by: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Vishal Verma 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/1547106849-3476-2-git-send-email-shirish.s@amd.com
Signed-off-by: Sasha Levin

x86/MCE: Save microcode revision in machine check records

2019-05-16T17:45:08+00:00

commit fa94d0c6e0f3431523f5701084d799c77c7d4a4f upstream.

Updating microcode used to be relatively rare. Now that it has become
more common we should save the microcode version in a machine check
record to make sure that those people looking at the error have this
important information bundled with the rest of the logged information.

[ Borislav: Simplify a bit. ]

Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: Yazen Ghannam 
Cc: linux-edac 
Link: http://lkml.kernel.org/r/20180301233449.24311-1-tony.luck@intel.com
[bwh: Backported to 4.4:
 - Also add earlier fields to struct mce, to match upstream UAPI
 - Adjust context]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

x86/mce: Improve error message when kernel cannot recover, p2

2019-05-16T17:45:03+00:00

commit 41f035a86b5b72a4f947c38e94239d20d595352a upstream.

In

  c7d606f560e4 ("x86/mce: Improve error message when kernel cannot recover")

a case was added for a machine check caused by a DATA access to poison
memory from the kernel. A case should have been added also for an
uncorrectable error during an instruction fetch in the kernel.

Add that extra case so the error message now reads:

  mce: [Hardware Error]: Machine check: Instruction fetch error in kernel

Fixes: c7d606f560e4 ("x86/mce: Improve error message when kernel cannot recover")
Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Pu Wen 
Cc: Thomas Gleixner 
Cc: x86-ml 
Link: https://lkml.kernel.org/r/20190225205940.15226-1-tony.luck@intel.com
Signed-off-by: Greg Kroah-Hartman

x86/MCE: Initialize mce.bank in the case of a fatal error in mce_no_way_out()

2019-02-20T09:13:17+00:00

commit d28af26faa0b1daf3c692603d46bc4687c16f19e upstream.

Internal injection testing crashed with a console log that said:

  mce: [Hardware Error]: CPU 7: Machine Check Exception: f Bank 0: bd80000000100134

This caused a lot of head scratching because the MCACOD (bits 15:0) of
that status is a signature from an L1 data cache error. But Linux says
that it found it in "Bank 0", which on this model CPU only reports L1
instruction cache errors.

The answer was that Linux doesn't initialize "m->bank" in the case that
it finds a fatal error in the mce_no_way_out() pre-scan of banks. If
this was a local machine check, then this partially initialized struct
mce is being passed to mce_panic().

Fix is simple: just initialize m->bank in the case of a fatal error.

Fixes: 40c36e2741d7 ("x86/mce: Fix incorrect "Machine check from unknown source" message")
Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov 
Cc: "H. Peter Anvin" 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Cc: Vishal Verma 
Cc: x86-ml 
Cc: stable@vger.kernel.org # v4.18 Note pre-v5.0 arch/x86/kernel/cpu/mce/core.c was called arch/x86/kernel/cpu/mcheck/mce.c
Link: https://lkml.kernel.org/r/20190201003341.10638-1-tony.luck@intel.com
Signed-off-by: Greg Kroah-Hartman

x86/MCE: Remove min interval polling limitation

2018-07-25T08:18:15+00:00

commit fbdb328c6bae0a7c78d75734a738b66b86dffc96 upstream.

commit b3b7c4795c ("x86/MCE: Serialize sysfs changes") introduced a min
interval limitation when setting the check interval for polled MCEs.
However, the logic is that 0 disables polling for corrected MCEs, see
Documentation/x86/x86_64/machinecheck. The limitation prevents disabling.

Remove this limitation and allow the value 0 to disable polling again.

Fixes: b3b7c4795c ("x86/MCE: Serialize sysfs changes")
Signed-off-by: Dewet Thibaut 
Signed-off-by: Alexander Sverdlin 
[ Massage commit message. ]
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: Tony Luck 
Cc: linux-edac 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180716084927.24869-1-alexander.sverdlin@nokia.com
Signed-off-by: Greg Kroah-Hartman

x86/mce: Fix incorrect "Machine check from unknown source" message

2018-07-11T14:03:50+00:00

commit 40c36e2741d7fe1e66d6ec55477ba5fd19c9c5d2 upstream.

Some injection testing resulted in the following console log:

  mce: [Hardware Error]: CPU 22: Machine Check Exception: f Bank 1: bd80000000100134
  mce: [Hardware Error]: RIP 10: {pmem_do_bvec+0x11d/0x330 [nd_pmem]}
  mce: [Hardware Error]: TSC c51a63035d52 ADDR 3234bc4000 MISC 88
  mce: [Hardware Error]: PROCESSOR 0:50654 TIME 1526502199 SOCKET 0 APIC 38 microcode 2000043
  mce: [Hardware Error]: Run the above through 'mcelog --ascii'
  Kernel panic - not syncing: Machine check from unknown source

This confused everybody because the first line quite clearly shows
that we found a logged error in "Bank 1", while the last line says
"unknown source".

The problem is that the Linux code doesn't do the right thing
for a local machine check that results in a fatal error.

It turns out that we know very early in the handler whether the
machine check is fatal. The call to mce_no_way_out() has checked
all the banks for the CPU that took the local machine check. If
it says we must crash, we can do so right away with the right
messages.

We do scan all the banks again. This means that we might initially
not see a problem, but during the second scan find something fatal.
If this happens we print a slightly different message (so I can
see if it actually every happens).

[ bp: Remove unneeded severity assignment. ]

Signed-off-by: Tony Luck 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: Ashok Raj 
Cc: Dan Williams 
Cc: Qiuxu Zhuo 
Cc: linux-edac 
Cc: stable@vger.kernel.org # 4.2
Link: http://lkml.kernel.org/r/52e049a497e86fd0b71c529651def8871c804df0.1527283897.git.tony.luck@intel.com
Signed-off-by: Greg Kroah-Hartman

x86/mce: Detect local MCEs properly

2018-07-11T14:03:50+00:00

commit fead35c68926682c90c995f22b48f1c8d78865c1 upstream.

Check the MCG_STATUS_LMCES bit on Intel to verify that current MCE is
local. It is always local on AMD.

Signed-off-by: Yazen Ghannam 
[ Massaged it a bit. Reflowed comments. Shut up -Wmaybe-uninitialized. ]
Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: linux-edac 
Link: http://lkml.kernel.org/r/1462019637-16474-8-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

x86/MCE: Serialize sysfs changes

2018-03-18T10:17:50+00:00

commit b3b7c4795ccab5be71f080774c45bbbcc75c2aaf upstream.

The check_interval file in

  /sys/devices/system/machinecheck/machinecheck

directory is a global timer value for MCE polling. If it is changed by one
CPU, mce_restart() broadcasts the event to other CPUs to delete and restart
the MCE polling timer and __mcheck_cpu_init_timer() reinitializes the
mce_timer variable.

If more than one CPU writes a specific value to the check_interval file
concurrently, mce_timer is not protected from such concurrent accesses and
all kinds of explosions happen. Since only root can write to those sysfs
variables, the issue is not a big deal security-wise.

However, concurrent writes to these configuration variables is void of
reason so the proper thing to do is to serialize the access with a mutex.

Boris:

 - Make store_int_with_restart() use device_store_ulong() to filter out
   negative intervals
 - Limit min interval to 1 second
 - Correct locking
 - Massage commit message

Signed-off-by: Seunghun Han 
Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Cc: Greg Kroah-Hartman 
Cc: Tony Luck 
Cc: linux-edac 
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180302202706.9434-1-kkamagui@gmail.com
Signed-off-by: Greg Kroah-Hartman

x86/ras/inject: Make it depend on X86_LOCAL_APIC=y

2018-02-25T10:03:42+00:00

commit d4b2ac63b0eae461fc10c9791084be24724ef57a upstream.

... and get rid of the annoying:

  arch/x86/kernel/cpu/mcheck/mce-inject.c:97:13: warning: ‘mce_irq_ipi’ defined but not used [-Wunused-function]

when doing randconfig builds.

Signed-off-by: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: Yazen Ghannam 
Cc: linux-edac 
Link: http://lkml.kernel.org/r/20170123183514.13356-2-bp@alien8.de
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman