releases/6.6.81/x86-microcode-intel-switch-to-kvmalloc.patch

From 0937c0624d82085ec90acde324c0bd6d9accfa20 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Mon, 2 Oct 2023 13:59:45 +0200
Subject: x86/microcode/intel: Switch to kvmalloc()

From: Thomas Gleixner <tglx@linutronix.de>

commit f24f204405f9875bc539c6e88553fd5ac913c867 upstream

Microcode blobs are getting larger and might soon reach the kmalloc()
limit. Switch over kvmalloc().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231002115902.564323243@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/x86/kernel/cpu/microcode/intel.c |   48 +++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 23 deletions(-)

--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -14,7 +14,6 @@
 #include <linux/earlycpio.h>
 #include <linux/firmware.h>
 #include <linux/uaccess.h>
-#include <linux/vmalloc.h>
 #include <linux/initrd.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
@@ -245,7 +244,7 @@ EXPORT_SYMBOL_GPL(intel_microcode_sanity
 
 static void update_ucode_pointer(struct microcode_intel *mc)
 {
-	kfree(ucode_patch_va);
+	kvfree(ucode_patch_va);
 
 	/*
 	 * Save the virtual address for early loading and for eventual free
@@ -256,11 +255,14 @@ static void update_ucode_pointer(struct
 
 static void save_microcode_patch(struct microcode_intel *patch)
 {
+	unsigned int size = get_totalsize(&patch->hdr);
 	struct microcode_intel *mc;
 
-	mc = kmemdup(patch, get_totalsize(&patch->hdr), GFP_KERNEL);
+	mc = kvmemdup(patch, size, GFP_KERNEL);
 	if (mc)
 		update_ucode_pointer(mc);
+	else
+		pr_err("Unable to allocate microcode memory size: %u\n", size);
 }
 
 /* Scan blob for microcode matching the boot CPUs family, model, stepping */
@@ -539,36 +541,34 @@ static enum ucode_state parse_microcode_
 
 		if (!copy_from_iter_full(&mc_header, sizeof(mc_header), iter)) {
 			pr_err("error! Truncated or inaccessible header in microcode data file\n");
-			break;
+			goto fail;
 		}
 
 		mc_size = get_totalsize(&mc_header);
 		if (mc_size < sizeof(mc_header)) {
 			pr_err("error! Bad data in microcode data file (totalsize too small)\n");
-			break;
+			goto fail;
 		}
-
 		data_size = mc_size - sizeof(mc_header);
 		if (data_size > iov_iter_count(iter)) {
 			pr_err("error! Bad data in microcode data file (truncated file?)\n");
-			break;
+			goto fail;
 		}
 
 		/* For performance reasons, reuse mc area when possible */
 		if (!mc || mc_size > curr_mc_size) {
-			vfree(mc);
-			mc = vmalloc(mc_size);
+			kvfree(mc);
+			mc = kvmalloc(mc_size, GFP_KERNEL);
 			if (!mc)
-				break;
+				goto fail;
 			curr_mc_size = mc_size;
 		}
 
 		memcpy(mc, &mc_header, sizeof(mc_header));
 		data = mc + sizeof(mc_header);
 		if (!copy_from_iter_full(data, data_size, iter) ||
-		    intel_microcode_sanity_check(mc, true, MC_HEADER_TYPE_MICROCODE) < 0) {
-			break;
-		}
+		    intel_microcode_sanity_check(mc, true, MC_HEADER_TYPE_MICROCODE) < 0)
+			goto fail;
 
 		if (cur_rev >= mc_header.rev)
 			continue;
@@ -576,24 +576,26 @@ static enum ucode_state parse_microcode_
 		if (!intel_find_matching_signature(mc, uci->cpu_sig.sig, uci->cpu_sig.pf))
 			continue;
 
-		vfree(new_mc);
+		kvfree(new_mc);
 		cur_rev = mc_header.rev;
 		new_mc  = mc;
 		mc = NULL;
 	}
 
-	vfree(mc);
-
-	if (iov_iter_count(iter)) {
-		vfree(new_mc);
-		return UCODE_ERROR;
-	}
+	if (iov_iter_count(iter))
+		goto fail;
 
+	kvfree(mc);
 	if (!new_mc)
 		return UCODE_NFOUND;
 
 	ucode_patch_late = (struct microcode_intel *)new_mc;
 	return UCODE_NEW;
+
+fail:
+	kvfree(mc);
+	kvfree(new_mc);
+	return UCODE_ERROR;
 }
 
 static bool is_blacklisted(unsigned int cpu)
@@ -652,9 +654,9 @@ static enum ucode_state request_microcod
 static void finalize_late_load(int result)
 {
 	if (!result)
-		save_microcode_patch(ucode_patch_late);
-
-	vfree(ucode_patch_late);
+		update_ucode_pointer(ucode_patch_late);
+	else
+		kvfree(ucode_patch_late);
 	ucode_patch_late = NULL;
 }