2 files changed, 67 insertions, 0 deletions

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 936a488d6cf6..274dfc481849 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -210,6 +210,70 @@ int __init efi_memblock_x86_reserve_range(void)
         return 0;
 }
 
+#define OVERFLOW_ADDR_SHIFT     (64 - EFI_PAGE_SHIFT)
+#define OVERFLOW_ADDR_MASK      (U64_MAX << OVERFLOW_ADDR_SHIFT)
+#define U64_HIGH_BIT            (~(U64_MAX >> 1))
+
+static bool __init efi_memmap_entry_valid(const efi_memory_desc_t *md, int i)
+{
+        u64 end = (md->num_pages << EFI_PAGE_SHIFT) + md->phys_addr - 1;
+        u64 end_hi = 0;
+        char buf[64];
+
+        if (md->num_pages == 0) {
+                end = 0;
+        } else if (md->num_pages > EFI_PAGES_MAX ||
+                   EFI_PAGES_MAX - md->num_pages <
+                   (md->phys_addr >> EFI_PAGE_SHIFT)) {
+                end_hi = (md->num_pages & OVERFLOW_ADDR_MASK)
+                        >> OVERFLOW_ADDR_SHIFT;
+
+                if ((md->phys_addr & U64_HIGH_BIT) && !(end & U64_HIGH_BIT))
+                        end_hi += 1;
+        } else {
+                return true;
+        }
+
+        pr_warn_once(FW_BUG "Invalid EFI memory map entries:\n");
+
+        if (end_hi) {
+                pr_warn("mem%02u: %s range=[0x%016llx-0x%llx%016llx] (invalid)\n",
+                        i, efi_md_typeattr_format(buf, sizeof(buf), md),
+                        md->phys_addr, end_hi, end);
+        } else {
+                pr_warn("mem%02u: %s range=[0x%016llx-0x%016llx] (invalid)\n",
+                        i, efi_md_typeattr_format(buf, sizeof(buf), md),
+                        md->phys_addr, end);
+        }
+        return false;
+}
+
+static void __init efi_clean_memmap(void)
+{
+        efi_memory_desc_t *out = efi.memmap.map;
+        const efi_memory_desc_t *in = out;
+        const efi_memory_desc_t *end = efi.memmap.map_end;
+        int i, n_removal;
+
+        for (i = n_removal = 0; in < end; i++) {
+                if (efi_memmap_entry_valid(in, i)) {
+                        if (out != in)
+                                memcpy(out, in, efi.memmap.desc_size);
+                        out = (void *)out + efi.memmap.desc_size;
+                } else {
+                        n_removal++;
+                }
+                in = (void *)in + efi.memmap.desc_size;
+        }
+
+        if (n_removal > 0) {
+                u64 size = efi.memmap.nr_map - n_removal;
+
+                pr_warn("Removing %d invalid memory map entries.\n", n_removal);
+                efi_memmap_install(efi.memmap.phys_map, size);
+        }
+}
+
 void __init efi_print_memmap(void)
 {
         efi_memory_desc_t *md;
@@ -472,6 +536,8 @@ void __init efi_init(void)
                 }
         }
 
+        efi_clean_memmap();
+
         if (efi_enabled(EFI_DBG))
                 efi_print_memmap();
 }
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 2d089487d2da..fda79cdf9f10 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -103,6 +103,7 @@ typedef	struct {
 
 #define EFI_PAGE_SHIFT          12
 #define EFI_PAGE_SIZE           (1UL << EFI_PAGE_SHIFT)
+#define EFI_PAGES_MAX           (U64_MAX >> EFI_PAGE_SHIFT)
 
 typedef struct {
         u32 type;