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Commit f9524e6f authored by Borislav Petkov's avatar Borislav Petkov
Browse files

x86/microcode/intel: Do the mc_saved_src NULL check first 



... and only then deref it. Also, shorten some variable names and rename
others so as to diminish the ubiquitous presence of the "mc_" prefix
everywhere and make it a bit more readable.

Use kcalloc so that we don't kfree() uninitialized memory on the unwind
path, as suggested by Quentin.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
parent 776d3cdc

arch/x86/kernel/cpu/microcode/intel_early.c

+22 −16
Original line number Diff line number Diff line
@@ -203,7 +203,7 @@ save_microcode(struct mc_saved_data *mc_saved_data, 
	       unsigned int mc_saved_count)

{

	int i, j;

	struct microcode_intel **mc_saved_p;

	struct microcode_intel **saved_ptr;

	int ret;



	if (!mc_saved_count)
@@ -212,39 +212,45 @@ save_microcode(struct mc_saved_data *mc_saved_data, 
	/*

	 * Copy new microcode data.

	 */

	mc_saved_p = kmalloc(mc_saved_count*sizeof(struct microcode_intel *),

			     GFP_KERNEL);

	if (!mc_saved_p)

	saved_ptr = kcalloc(mc_saved_count, sizeof(struct microcode_intel *), GFP_KERNEL);

	if (!saved_ptr)

		return -ENOMEM;



	for (i = 0; i < mc_saved_count; i++) {

		struct microcode_intel *mc = mc_saved_src[i];

		struct microcode_header_intel *mc_header = &mc->hdr;

		unsigned long mc_size = get_totalsize(mc_header);

		mc_saved_p[i] = kmalloc(mc_size, GFP_KERNEL);

		if (!mc_saved_p[i]) {

			ret = -ENOMEM;

			goto err;

		}

		struct microcode_header_intel *mc_hdr;

		struct microcode_intel *mc;

		unsigned long size;



		if (!mc_saved_src[i]) {

			ret = -EINVAL;

			goto err;

		}

		memcpy(mc_saved_p[i], mc, mc_size);



		mc     = mc_saved_src[i];

		mc_hdr = &mc->hdr;

		size   = get_totalsize(mc_hdr);



		saved_ptr[i] = kmalloc(size, GFP_KERNEL);

		if (!saved_ptr[i]) {

			ret = -ENOMEM;

			goto err;

		}



		memcpy(saved_ptr[i], mc, size);

	}



	/*

	 * Point to newly saved microcode.

	 */

	mc_saved_data->mc_saved = mc_saved_p;

	mc_saved_data->mc_saved = saved_ptr;

	mc_saved_data->mc_saved_count = mc_saved_count;



	return 0;



err:

	for (j = 0; j <= i; j++)

		kfree(mc_saved_p[j]);

	kfree(mc_saved_p);

		kfree(saved_ptr[j]);

	kfree(saved_ptr);



	return ret;

}