Commit-ID: f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 Gitweb: http://git.kernel.org/tip/f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 Author: Quentin Casasnovas <[email protected]> AuthorDate: Tue, 3 Feb 2015 13:00:22 +0100 Committer: Borislav Petkov <[email protected]> CommitDate: Thu, 19 Feb 2015 12:41:37 +0100
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 <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: Fenghua Yu <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Borislav Petkov <[email protected]> --- arch/x86/kernel/cpu/microcode/intel_early.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c index ec9df6f..5e109a3 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
