scst: Use vmalloc_array() and vcalloc()

Use vmalloc_array() and vcalloc() to protect against multiplication
overflows.

The changes were done using the following Coccinelle
semantic patch:

// <smpl>
@initialize:ocaml@
@@

let rename alloc =
  match alloc with
    "vmalloc" -> "vmalloc_array"
  | "vzalloc" -> "vcalloc"
  | _ -> failwith "unknown"

@@
    size_t e1,e2;
    constant C1, C2;
    expression E1, E2, COUNT, x1, x2, x3;
    typedef u8;
    typedef __u8;
    type t = {u8,__u8,char,unsigned char};
    identifier alloc = {vmalloc,vzalloc};
    fresh identifier realloc = script:ocaml(alloc) { rename alloc };
@@

(
      alloc(x1*x2*x3)
|
      alloc(C1 * C2)
|
      alloc((sizeof(t)) * (COUNT), ...)
|
-     alloc((e1) * (e2))
+     realloc(e1, e2)
|
-     alloc((e1) * (COUNT))
+     realloc(COUNT, e1)
|
-     alloc((E1) * (E2))
+     realloc(E1, E2)
)
// </smpl>

iscsi-scst/kernel/isert-scst/iser_rdma.c

@@ -938,8 +938,7 @@ static struct isert_device *isert_device_create(struct ib_device *ib_dev)
 		goto free_isert_dev;
 	}
 
-	isert_dev->cq_desc = vmalloc(sizeof(*isert_dev->cq_desc) *
-				     isert_dev->num_cqs);
+	isert_dev->cq_desc = vmalloc_array(isert_dev->num_cqs, sizeof(*isert_dev->cq_desc));
 	if (unlikely(isert_dev->cq_desc == NULL)) {
 		PRINT_ERROR("Failed to allocate %zd bytes for iser cq_desc",
 			    sizeof(*isert_dev->cq_desc) * isert_dev->num_cqs);

qla2x00t-32gbit/qla_init.c

@@ -8437,7 +8437,7 @@ qla24xx_load_risc_flash(scsi_qla_host_t *vha, uint32_t *srisc_addr,
 		ql_dbg(ql_dbg_init, vha, 0x0163,
 		    "-> fwdt%u template allocate template %#x words...\n",
 		    j, risc_size);
-		fwdt->template = vmalloc(risc_size * sizeof(*dcode));
+		fwdt->template = vmalloc_array(risc_size, sizeof(*dcode));
 		if (!fwdt->template) {
 			ql_log(ql_log_warn, vha, 0x0164,
 			    "-> fwdt%u failed allocate template.\n", j);
@@ -8692,7 +8692,7 @@ qla24xx_load_risc_blob(scsi_qla_host_t *vha, uint32_t *srisc_addr)
 		ql_dbg(ql_dbg_init, vha, 0x0173,
 		    "-> fwdt%u template allocate template %#x words...\n",
 		    j, risc_size);
-		fwdt->template = vmalloc(risc_size * sizeof(*dcode));
+		fwdt->template = vmalloc_array(risc_size, sizeof(*dcode));
 		if (!fwdt->template) {
 			ql_log(ql_log_warn, vha, 0x0174,
 			    "-> fwdt%u failed allocate template.\n", j);

scst/include/backport.h

@@ -849,6 +849,28 @@ static inline void kvfree(void *addr)
 }
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 18, 0) &&			\
+	(LINUX_VERSION_CODE >> 8 != KERNEL_VERSION(5, 15, 0) >> 8 ||	\
+	 LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 54)) &&		\
+	(!defined(RHEL_RELEASE_CODE) ||					\
+	 RHEL_RELEASE_CODE -0 < RHEL_RELEASE_VERSION(9, 0)) &&		\
+	(!defined(UEK_KABI_RENAME) ||					\
+	 LINUX_VERSION_CODE < KERNEL_VERSION(5, 15, 0))
+/*
+ * See also commit a8749a35c3990 ("mm: vmalloc: introduce array allocation functions") # v5.18,
+ * v5.15.54.
+ */
+static inline void *vmalloc_array(size_t n, size_t size)
+{
+	return vmalloc(n * size);
+}
+
+static inline void *vcalloc(size_t n, size_t size)
+{
+	return vzalloc(n * size);
+}
+#endif
+
 /* <linux/shrinker.h> */
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(6, 0, 0) &&		\

scst/src/scst_dlm.c

@@ -304,11 +304,10 @@ static int scst_copy_from_dlm(struct scst_device *dev, dlm_lockspace_t *ls,
 
 	nr_registrants = be32_to_cpu(lvb->nr_registrants);
 	if (nr_registrants) {
-		reg_lksb = vzalloc((sizeof(*reg_lksb) + PR_DLM_LVB_LEN) *
-				   nr_registrants);
+		reg_lksb = vcalloc(nr_registrants, sizeof(*reg_lksb) + PR_DLM_LVB_LEN);
 		if (!reg_lksb) {
-			PRINT_ERROR("%s: failed to allocate %d * %zd bytes of"
-				    " memory", __func__, nr_registrants,
+			PRINT_ERROR("%s: failed to allocate %u * %zu bytes of memory",
+				    __func__, nr_registrants,
 				    sizeof(*reg_lksb) + PR_DLM_LVB_LEN);
 			goto out;
 		}