x86/boot: Fix memremap of setup_indirect structures

As documented, the setup_indirect structure is nested inside
the setup_data structures in the setup_data list. The code currently
accesses the fields inside the setup_indirect structure but only
the sizeof(struct setup_data) is being memremapped. No crash
occurred but this is just due to how the area is remapped under the
covers.

Properly memremap both the setup_data and setup_indirect structures
in these cases before accessing them.

Fixes: b3c72fc9a78e ("x86/boot: Introduce setup_indirect")
Signed-off-by: Ross Philipson <ross.philipson@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1645668456-22036-2-git-send-email-ross.philipson@oracle.com

1 files changed, 20 insertions, 4 deletions

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 026031b3b782..ab666c4cd357 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -615,6 +615,7 @@ static bool memremap_is_efi_data(resource_size_t phys_addr,
 static bool memremap_is_setup_data(resource_size_t phys_addr,
 				   unsigned long size)
 {
+	struct setup_indirect *indirect;
 	struct setup_data *data;
 	u64 paddr, paddr_next;
 
@@ -627,6 +628,10 @@ static bool memremap_is_setup_data(resource_size_t phys_addr,
 
 		data = memremap(paddr, sizeof(*data),
 				MEMREMAP_WB | MEMREMAP_DEC);
+		if (!data) {
+			pr_warn("failed to memremap setup_data entry\n");
+			return false;
+		}
 
 		paddr_next = data->next;
 		len = data->len;
@@ -636,10 +641,21 @@ static bool memremap_is_setup_data(resource_size_t phys_addr,
 			return true;
 		}
 
-		if (data->type == SETUP_INDIRECT &&
-		    ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
-			paddr = ((struct setup_indirect *)data->data)->addr;
-			len = ((struct setup_indirect *)data->data)->len;
+		if (data->type == SETUP_INDIRECT) {
+			memunmap(data);
+			data = memremap(paddr, sizeof(*data) + len,
+					MEMREMAP_WB | MEMREMAP_DEC);
+			if (!data) {
+				pr_warn("failed to memremap indirect setup_data\n");
+				return false;
+			}
+
+			indirect = (struct setup_indirect *)data->data;
+
+			if (indirect->type != SETUP_INDIRECT) {
+				paddr = indirect->addr;
+				len = indirect->len;
+			}
 		}
 
 		memunmap(data);