libblkid: exfat: validate more fields

diff --git a/libblkid/src/superblocks/exfat.c b/libblkid/src/superblocks/exfat.c
index 003c08f6f4f147597002f129365707af41aeddd6..c07054ac433aee25103c848e4ac2a2472daedfe9 100644 (file)
--- a/libblkid/src/superblocks/exfat.c
+++ b/libblkid/src/superblocks/exfat.c
@@ -167,6 +167,16 @@ static int probe_exfat(blkid_probe pr, const struct blkid_idmag *mag)
        if (!sb || !CLUSTER_SIZE(sb))
                return errno ? -errno : BLKID_PROBE_NONE;
 
+       if (le16_to_cpu(sb->BootSignature) != 0xAA55)
+               return BLKID_PROBE_NONE;
+
+       if (memcmp(sb->JumpBoot, "\xEB\x76\x90", 3) != 0)
+               return BLKID_PROBE_NONE;
+
+       for (size_t i = 0; i < sizeof(sb->MustBeZero); i++)
+               if (sb->MustBeZero[i] != 0x00)
+                       return BLKID_PROBE_NONE;
+
        if (!exfat_validate_checksum(pr, sb))
                return BLKID_PROBE_NONE;