ipc3: check alignment of ext data

Sizes are not currently checked for alignment, this can generated
unaligned pointers for aligned types which is undefined behaviour.

Signed-off-by: Curtis Malainey <[email protected]>

src/ipc/ipc3/helper.c

@@ -80,6 +80,7 @@ static const struct comp_driver *get_drv(struct sof_ipc_comp *comp)
  const struct comp_driver *drv = NULL;
  struct comp_driver_info *info;
  struct sof_ipc_comp_ext *comp_ext;
+ uintptr_t offset;
  k_spinlock_key_t key;
 
  /* do we have extended data ? */
@@ -112,9 +113,13 @@ static const struct comp_driver *get_drv(struct sof_ipc_comp *comp)
  goto out;
  }
 
- comp_ext = (struct sof_ipc_comp_ext *)
- ((uint8_t *)comp + comp->hdr.size -
- comp->ext_data_length);
+ offset = comp->hdr.size - comp->ext_data_length;
+ if ((offset & 0x3) != 0) {
+ tr_err(&comp_tr, "Invalid ext data offset %lx", offset);
+ goto out;
+ }
+
+ comp_ext = (struct sof_ipc_comp_ext *)((uint8_t *)comp + offset);
 
  /* UUID is first item in extended data - check its big enough */
  if (comp->ext_data_length < UUID_SIZE) {