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authorQuentin Casasnovas <quentin.casasnovas@oracle.com>2015-02-03 13:00:22 +0100
committerJiri Slaby <jslaby@suse.cz>2015-04-09 14:13:45 +0200
commitc5988181af3b41381c4d20e08ca6852f99f95417 (patch)
treedb224506de88050912fa9f16f6440527e23656e2 /arch
parent17e7f51dec81495e6571ce8617e3da8ee2e47e78 (diff)
x86/microcode/intel: Guard against stack overflow in the loader
commit f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 upstream. 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> Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/microcode_intel_early.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/microcode_intel_early.c b/arch/x86/kernel/microcode_intel_early.c
index 1575deb2e636..c44f7db7ce44 100644
--- a/arch/x86/kernel/microcode_intel_early.c
+++ b/arch/x86/kernel/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);