diff --git a/fs/befs/befs.h b/fs/befs/befs.h
index 7cd47245694d..5490024adb33 100644
--- a/fs/befs/befs.h
+++ b/fs/befs/befs.h
@@ -13,7 +13,7 @@
 
 /* used in debug.c */
 #define BEFS_VERSION "0.9.3"
-
+#define BEFS_MAX_BLOCK_SHIFT 31
 
 typedef u64 befs_blocknr_t;
 /*
@@ -133,7 +133,7 @@ blockno2iaddr(struct super_block *sb, befs_blocknr_t blockno)
 
 	iaddr.allocation_group = blockno >> BEFS_SB(sb)->ag_shift;
 	iaddr.start =
-	    blockno - (iaddr.allocation_group << BEFS_SB(sb)->ag_shift);
+		blockno - (iaddr.allocation_group << BEFS_SB(sb)->ag_shift);
 	iaddr.len = 1;
 
 	return iaddr;
diff --git a/fs/befs/super.c b/fs/befs/super.c
index 7c50025c99d8..f2aeb2ed6e77 100644
--- a/fs/befs/super.c
+++ b/fs/befs/super.c
@@ -88,6 +88,17 @@ befs_check_sb(struct super_block *sb)
 		return BEFS_ERR;
 	}
 
+	/*
+	 * block_shift check added so that overflow does not
+	 * occur during the block_size check
+	 */
+
+	if (befs_sb->block_shift > BEFS_MAX_BLOCK_SHIFT) {
+		befs_error(sb, "block_size too large. "
+			   "Corruption likely.");
+		return BEFS_ERR;
+	}
+
 	/*
 	 * block_shift and block_size encode the same information
 	 * in different ways as a consistency check.