public-mirrors/linux
1
0
Fork 0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-08-05 16:54:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions
linux/arch/x86
History
Junichi Nomura 2e86222c67 x86/microcode/intel: Use correct buffer size for saving microcode data 
In generic_load_microcode(), curr_mc_size is the size of the last
allocated buffer and since we have this performance "optimization"
there to vmalloc a new buffer only when the current one is bigger,
curr_mc_size ends up becoming the size of the biggest buffer we've seen
so far.

However, we end up saving the microcode patch which matches our CPU
and its size is not curr_mc_size but the respective mc_size during the
iteration while we're staring at it.

So save that mc_size into a separate variable and use it to store the
previously found microcode buffer.

Without this fix, we could get oops like this:

  BUG: unable to handle kernel paging request at ffffc9000e30f000
  IP: __memcpy+0x12/0x20
  ...
  Call Trace:
  ? kmemdup+0x43/0x60
  __alloc_microcode_buf+0x44/0x70
  save_microcode_patch+0xd4/0x150
  generic_load_microcode+0x1b8/0x260
  request_microcode_user+0x15/0x20
  microcode_write+0x91/0x100
  __vfs_write+0x34/0x120
  vfs_write+0xc1/0x130
  SyS_write+0x56/0xc0
  do_syscall_64+0x6c/0x160
  entry_SYSCALL64_slow_path+0x25/0x25

Fixes: 06b8534cb7 ("x86/microcode: Rework microcode loading")
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/4f33cbfd-44f2-9bed-3b66-7446cd14256f@ce.jp.nec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-01-09 23:11:15 +01:00
..
boot x86/boot: Add missing declaration of string functions 2017-01-09 11:53:05 +01:00
configs
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2016-12-14 13:31:29 -08:00
entry Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
events cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
ia32 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
include x86/microcode/intel: Add a helper which gives the microcode revision 2017-01-09 23:11:14 +01:00
kernel x86/microcode/intel: Use correct buffer size for saving microcode data 2017-01-09 23:11:15 +01:00
kvm Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
lguest clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
lib Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
net bpf: xdp: Allow head adjustment in XDP prog 2016-12-08 14:25:13 -05:00
oprofile x86/oprofile/nmi: Convert to hotplug state machine 2016-11-22 23:34:43 +01:00
pci xen: features and fixes for 4.10 rc0 2016-12-13 16:07:55 -08:00
platform x86/platform/intel-mid: Rename 'spidev' to 'mrfld_spidev' 2017-01-05 09:03:29 +01:00
power Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-18 13:59:10 -08:00
purgatory
ras
realmode x86/build: Don't use $(LINUXINCLUDE) twice 2016-11-28 07:49:17 +01:00
tools x86/tools: Fix gcc-7 warning in relocs.c 2016-12-19 11:50:24 +01:00
um Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
video
xen Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
.gitignore
Kbuild
Kconfig Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-22 09:25:45 -08:00
Kconfig.cpu
Kconfig.debug
Makefile
Makefile.um
Makefile_32.cpu