x86/microcode/intel: Guard against stack overflow in the loader
authorQuentin Casasnovas <quentin.casasnovas@oracle.com>
Tue, 3 Feb 2015 12:00:22 +0000 (13:00 +0100)
committerBorislav Petkov <bp@suse.de>
Thu, 19 Feb 2015 11:41:37 +0000 (12:41 +0100)
commitf84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4
tree0f2d2a121be88ce30a4c7926ee1a016139ec8b69
parente36f014edff70fc02b3d3d79cead1d58f289332e
x86/microcode/intel: Guard against stack overflow in the loader

mc_saved_tmp is a static array allocated on the stack, we need to make
sure mc_saved_count stays within its bounds, otherwise we're overflowing
the stack in _save_mc(). A specially crafted microcode header could lead
to a kernel crash or potentially kernel execution.

Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/1422964824-22056-1-git-send-email-quentin.casasnovas@oracle.com
Signed-off-by: Borislav Petkov <bp@suse.de>
arch/x86/kernel/cpu/microcode/intel_early.c