diff options
| -rw-r--r-- | arch/x86/boot/edd.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/boot/edd.c b/arch/x86/boot/edd.c index bf4ae6ff518..067e28cd3c5 100644 --- a/arch/x86/boot/edd.c +++ b/arch/x86/boot/edd.c @@ -43,6 +43,7 @@ static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig) char *mbrbuf_ptr, *mbrbuf_end; u32 buf_base, mbr_base; extern char _end[]; + u16 mbr_magic; sector_size = ei->params.bytes_per_sector; if (!sector_size) @@ -60,11 +61,15 @@ static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig) if (mbrbuf_end > (char *)(size_t)boot_params.hdr.heap_end_ptr) return -1; + memset(mbrbuf_ptr, 0, sector_size); if (read_mbr(devno, mbrbuf_ptr)) return -1; *mbrsig = *(u32 *)&mbrbuf_ptr[EDD_MBR_SIG_OFFSET]; - return 0; + mbr_magic = *(u16 *)&mbrbuf_ptr[510]; + + /* check for valid MBR magic */ + return mbr_magic == 0xAA55 ? 0 : -1; } static int get_edd_info(u8 devno, struct edd_info *ei) |