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authorQuentin Casasnovas <quentin.casasnovas@oracle.com>2015-02-03 13:00:22 +0100
committerBorislav Petkov <bp@suse.de>2015-02-19 12:41:37 +0100
commitf84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 (patch)
tree0f2d2a121be88ce30a4c7926ee1a016139ec8b69 /arch
parente36f014edff70fc02b3d3d79cead1d58f289332e (diff)
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/cpu/microcode/intel_early.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c
index ec9df6f9cd47..5e109a31f62b 100644
--- a/arch/x86/kernel/cpu/microcode/intel_early.c
+++ b/arch/x86/kernel/cpu/microcode/intel_early.c
@@ -321,7 +321,7 @@ get_matching_model_microcode(int cpu, unsigned long start,
unsigned int mc_saved_count = mc_saved_data->mc_saved_count;
int i;
- while (leftover) {
+ while (leftover && mc_saved_count < ARRAY_SIZE(mc_saved_tmp)) {
mc_header = (struct microcode_header_intel *)ucode_ptr;
mc_size = get_totalsize(mc_header);