projects/linux·commit 9376906c

Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

9376906c · Linus Torvalds <[email protected]> · 2017-06-10 10:12:14 -07:00

Pull EFI fix from Ingo Molnar:
 "A boot crash fix for certain systems where the kernel would trust a
  piece of firmware data it should not have"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Fix boot panic because of invalid BGRT image address
Commit
9376906c17fa975bf6a7ea9dd124be697bcda289
Parents
179145e6 · 792ef14d

Merge commit. Changes below are compared with the first parent: 179145e6.

Changes

1 files changed · +25 −1

FileStatusAddDelContent
drivers/firmware/efi/efi-bgrt.cmodified+25−1View file

drivers/firmware/efi/efi-bgrt.c

View file
diff --git a/drivers/firmware/efi/efi-bgrt.c b/drivers/firmware/efi/efi-bgrt.c
index 8bf2732..b58233e 100644
--- a/drivers/firmware/efi/efi-bgrt.c
+++ b/drivers/firmware/efi/efi-bgrt.c
@@ -27,6 +27,26 @@ struct bmp_header {
u32 size;
} __packed;
+static bool efi_bgrt_addr_valid(u64 addr)
+{
+ efi_memory_desc_t *md;
+
+ for_each_efi_memory_desc(md) {
+ u64 size;
+ u64 end;
+
+ if (md->type != EFI_BOOT_SERVICES_DATA)
+ continue;
+
+ size = md->num_pages << EFI_PAGE_SHIFT;
+ end = md->phys_addr + size;
+ if (addr >= md->phys_addr && addr < end)
+ return true;
+ }
+
+ return false;
+}
+
void __init efi_bgrt_init(struct acpi_table_header *table)
{
void *image;
@@ -36,7 +56,7 @@ void __init efi_bgrt_init(struct acpi_table_header *table)
if (acpi_disabled)
return;
- if (!efi_enabled(EFI_BOOT))
+ if (!efi_enabled(EFI_MEMMAP))
return;
if (table->length < sizeof(bgrt_tab)) {
@@ -65,6 +85,10 @@ void __init efi_bgrt_init(struct acpi_table_header *table)
goto out;
}
+ if (!efi_bgrt_addr_valid(bgrt->image_address)) {
+ pr_notice("Ignoring BGRT: invalid image address\n");
+ goto out;
+ }
image = early_memremap(bgrt->image_address, sizeof(bmp_header));
if (!image) {
pr_notice("Ignoring BGRT: failed to map image header memory\n");