linux-stable.git/arch/x86/kernel/cpu/microcode/intel_lib.c, branch linux-4.7.y

x86/microcode/intel: Drop orig_sum from ext signature checksum

2016-03-08T08:08:45+00:00

It is 0 because for !0 values we would have exited already.

Signed-off-by: Borislav Petkov 
Link: http://lkml.kernel.org/r/1457345404-28884-6-git-send-email-bp@alien8.de
Signed-off-by: Thomas Gleixner

x86/microcode/intel: Improve microcode sanity-checking error messages

2016-03-08T08:08:45+00:00

Turn them into proper sentences. Add comments to microcode_sanity_check() to
explain what it does.

Signed-off-by: Borislav Petkov 
Link: http://lkml.kernel.org/r/1457345404-28884-5-git-send-email-bp@alien8.de
Signed-off-by: Thomas Gleixner

x86/microcode/intel: Merge two consecutive if-statements

2016-03-08T08:08:45+00:00

Merge the two consecutive "if (ext_table_size)". No functional change.

Signed-off-by: Borislav Petkov 
Link: http://lkml.kernel.org/r/1457345404-28884-4-git-send-email-bp@alien8.de
Signed-off-by: Thomas Gleixner

x86/microcode/intel: Get rid of DWSIZE

2016-03-08T08:08:44+00:00

sizeof(u32) is perfectly clear as it is.

Signed-off-by: Borislav Petkov 
Link: http://lkml.kernel.org/r/1457345404-28884-3-git-send-email-bp@alien8.de
Signed-off-by: Thomas Gleixner

x86/microcode/intel: Change checksum variables to u32

2016-03-08T08:08:44+00:00

Microcode checksum verification should be done using unsigned 32-bit
values otherwise the calculation overflow results in undefined
behaviour.

This is also nicely documented in the SDM, section "Microcode Update
Checksum":

  "To check for a corrupt microcode update, software must perform a
  unsigned DWORD (32-bit) checksum of the microcode update. Even though
  some fields are signed, the checksum procedure treats all DWORDs as
  unsigned. Microcode updates with a header version equal to 00000001H
  must sum all DWORDs that comprise the microcode update. A valid
  checksum check will yield a value of 00000000H."

but for some reason the code has been using ints from the very
beginning.

In practice, this bug possibly manifested itself only when doing the
microcode data checksum - apparently, currently shipped Intel microcode
doesn't have an extended signature table for which we do checksum
verification too.

  UBSAN: Undefined behaviour in arch/x86/kernel/cpu/microcode/intel_lib.c:105:12
  signed integer overflow:
  -1500151068 + -2125470173 cannot be represented in type 'int'
  CPU: 0 PID: 0 Comm: swapper Not tainted 4.5.0-rc5+ #495
  ...
  Call Trace:
   dump_stack
   ? inotify_ioctl
   ubsan_epilogue
   handle_overflow
   __ubsan_handle_add_overflow
   microcode_sanity_check
   get_matching_model_microcode.isra.2.constprop.8
   ? early_idt_handler_common
   ? strlcpy
   ? find_cpio_data
   load_ucode_intel_bsp
   load_ucode_bsp
   ? load_ucode_bsp
   x86_64_start_kernel

[ Expand and massage commit message. ]
Signed-off-by: Chris Bainbridge 
Signed-off-by: Borislav Petkov 
Cc: hmh@hmh.eng.br
Link: http://lkml.kernel.org/r/1456834359-5132-1-git-send-email-chris.bainbridge@gmail.com
Signed-off-by: Thomas Gleixner

x86/microcode: Remove modularization leftovers

2015-10-21T09:22:12+00:00

Remove the remaining module functionality leftovers. Make
"dis_ucode_ldr" an early_param and make it static again. Drop
module aliases, autoloading table, description, etc.

Bump version number, while at it.

Signed-off-by: Borislav Petkov 
Cc: Andy Lutomirski 
Cc: Arjan van de Ven 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Jones 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Len Brown 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Rafael J. Wysocki 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Link: http://lkml.kernel.org/r/1445334889-300-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/microcode/intel: Rename get_matching_sig()

2015-05-18T07:32:37+00:00

... to find_matching_signature() which is exactly what it does.

No functionality change.

Signed-off-by: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Quentin Casasnovas 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1431860101-14847-5-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/microcode/intel: Simplify get_matching_sig()

2015-05-18T07:32:36+00:00

Unclutter function, make it a bit more readable, drop local
variables.

No functionality change.

Signed-off-by: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Quentin Casasnovas 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1431860101-14847-4-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/microcode/intel: Simplify update_match_cpu()

2015-05-18T07:32:36+00:00

Drop unreadable macro, deconstruct compound conditional
statement into single ones and return early if they match. Add
comments.

There should be no functionality change resulting from this
patch.

Signed-off-by: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Quentin Casasnovas 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1431860101-14847-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar

x86/microcode/intel: Rename get_matching_microcode

2015-05-18T07:32:36+00:00

... to has_newer_microcode() as it does exactly that: checks
whether binary data @mc has newer microcode patch than the
applied one. Move @mc to be the first function arg too.

Signed-off-by: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Quentin Casasnovas 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1431860101-14847-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar