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authorLinus Torvalds <torvalds@linux-foundation.org>2017-06-10 10:12:14 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-06-10 10:12:14 -0700
commit9376906c17fa975bf6a7ea9dd124be697bcda289 (patch)
treef998d3d0a105daef7e78fc4457d33ce5d0c84e38
parent179145e6312b1ccb1731841360d7fcaf2f4abc7a (diff)
parent792ef14df5c585c19b2831673a077504a09e5203 (diff)
Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
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
-rw-r--r--drivers/firmware/efi/efi-bgrt.c26
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/firmware/efi/efi-bgrt.c b/drivers/firmware/efi/efi-bgrt.c
index 8bf27323f7a3..b58233e4ed71 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");