Merge tag 's390-6.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 fixes from Vasily Gorbik:

 - Fix IOMMU bitmap allocation in s390 PCI to avoid out of bounds access
   when IOMMU pages aren't a multiple of 64

 - Fix kasan crashes when accessing DCSS mapping in memory holes by
   adding corresponding kasan zero shadow mappings

 - Fix a memory leak in css_alloc_subchannel in case
   dma_set_coherent_mask fails

* tag 's390-6.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/pci: fix iommu bitmap allocation
  s390/kasan: handle DCSS mapping in memory holes
  s390/cio: fix a memleak in css_alloc_subchannel

Author: torvalds

arch/s390/boot/vmem.c

@@ -57,6 +57,7 @@ static void kasan_populate_shadow(void)
 	pmd_t pmd_z = __pmd(__pa(kasan_early_shadow_pte) | _SEGMENT_ENTRY);
 	pud_t pud_z = __pud(__pa(kasan_early_shadow_pmd) | _REGION3_ENTRY);
 	p4d_t p4d_z = __p4d(__pa(kasan_early_shadow_pud) | _REGION2_ENTRY);
+	unsigned long memgap_start = 0;
 	unsigned long untracked_end;
 	unsigned long start, end;
 	int i;
@@ -101,8 +102,12 @@ static void kasan_populate_shadow(void)
 	 * +- shadow end ----+---------+- shadow end ---+
 	 */
 
-	for_each_physmem_usable_range(i, &start, &end)
+	for_each_physmem_usable_range(i, &start, &end) {
 		kasan_populate(start, end, POPULATE_KASAN_MAP_SHADOW);
+		if (memgap_start && physmem_info.info_source == MEM_DETECT_DIAG260)
+			kasan_populate(memgap_start, start, POPULATE_KASAN_ZERO_SHADOW);
+		memgap_start = end;
+	}
 	if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
 		untracked_end = VMALLOC_START;
 		/* shallowly populate kasan shadow for vmalloc and modules */

arch/s390/pci/pci_dma.c

@@ -564,6 +564,17 @@ static void s390_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 		s->dma_length = 0;
 	}
 }
+
+static unsigned long *bitmap_vzalloc(size_t bits, gfp_t flags)
+{
+	size_t n = BITS_TO_LONGS(bits);
+	size_t bytes;
+
+	if (unlikely(check_mul_overflow(n, sizeof(unsigned long), &bytes)))
+		return NULL;
+
+	return vzalloc(bytes);
+}
 
 int zpci_dma_init_device(struct zpci_dev *zdev)
 {
@@ -604,13 +615,13 @@ int zpci_dma_init_device(struct zpci_dev *zdev)
 				zdev->end_dma - zdev->start_dma + 1);
 	zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1;
 	zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
-	zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
+	zdev->iommu_bitmap = bitmap_vzalloc(zdev->iommu_pages, GFP_KERNEL);
 	if (!zdev->iommu_bitmap) {
 		rc = -ENOMEM;
 		goto free_dma_table;
 	}
 	if (!s390_iommu_strict) {
-		zdev->lazy_bitmap = vzalloc(zdev->iommu_pages / 8);
+		zdev->lazy_bitmap = bitmap_vzalloc(zdev->iommu_pages, GFP_KERNEL);
 		if (!zdev->lazy_bitmap) {
 			rc = -ENOMEM;
 			goto free_bitmap;

drivers/s390/cio/css.c

@@ -233,17 +233,19 @@ struct subchannel *css_alloc_subchannel(struct subchannel_id schid,
 	 */
 	ret = dma_set_coherent_mask(&sch->dev, DMA_BIT_MASK(31));
 	if (ret)
-		goto err;
+		goto err_lock;
 	/*
 	 * But we don't have such restrictions imposed on the stuff that
 	 * is handled by the streaming API.
 	 */
 	ret = dma_set_mask(&sch->dev, DMA_BIT_MASK(64));
 	if (ret)
-		goto err;
+		goto err_lock;
 
 	return sch;
 
+err_lock:
+	kfree(sch->lock);
 err:
 	kfree(sch);
 	return ERR_PTR(ret);