1 files changed, 29 insertions, 45 deletions

diff --git a/fs/udf/balloc.c b/fs/udf/balloc.c
index ab3ffc355949..d8fc11765d61 100644
--- a/fs/udf/balloc.c
+++ b/fs/udf/balloc.c
@@ -18,6 +18,7 @@
 #include "udfdecl.h"
 
 #include <linux/bitops.h>
+#include <linux/overflow.h>
 
 #include "udf_i.h"
 #include "udf_sb.h"
@@ -64,14 +65,18 @@ static int read_block_bitmap(struct super_block *sb,
 	}
 
 	for (i = 0; i < count; i++)
-		if (udf_test_bit(i + off, bh->b_data))
+		if (udf_test_bit(i + off, bh->b_data)) {
+			bitmap->s_block_bitmap[bitmap_nr] =
+							ERR_PTR(-EFSCORRUPTED);
+			brelse(bh);
 			return -EFSCORRUPTED;
+		}
 	return 0;
 }
 
-static int __load_block_bitmap(struct super_block *sb,
-			       struct udf_bitmap *bitmap,
-			       unsigned int block_group)
+static int load_block_bitmap(struct super_block *sb,
+			     struct udf_bitmap *bitmap,
+			     unsigned int block_group)
 {
 	int retval = 0;
 	int nr_groups = bitmap->s_nr_groups;
@@ -81,8 +86,15 @@ static int __load_block_bitmap(struct super_block *sb,
 			  block_group, nr_groups);
 	}
 
-	if (bitmap->s_block_bitmap[block_group])
+	if (bitmap->s_block_bitmap[block_group]) {
+		/*
+		 * The bitmap failed verification in the past. No point in
+		 * trying again.
+		 */
+		if (IS_ERR(bitmap->s_block_bitmap[block_group]))
+			return PTR_ERR(bitmap->s_block_bitmap[block_group]);
 		return block_group;
+	}
 
 	retval = read_block_bitmap(sb, bitmap, block_group, block_group);
 	if (retval < 0)
@@ -91,23 +103,6 @@ static int __load_block_bitmap(struct super_block *sb,
 	return block_group;
 }
 
-static inline int load_block_bitmap(struct super_block *sb,
-				    struct udf_bitmap *bitmap,
-				    unsigned int block_group)
-{
-	int slot;
-
-	slot = __load_block_bitmap(sb, bitmap, block_group);
-
-	if (slot < 0)
-		return slot;
-
-	if (!bitmap->s_block_bitmap[slot])
-		return -EIO;
-
-	return slot;
-}
-
 static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
 {
 	struct udf_sb_info *sbi = UDF_SB(sb);
@@ -129,7 +124,6 @@ static void udf_bitmap_free_blocks(struct super_block *sb,
 {
 	struct udf_sb_info *sbi = UDF_SB(sb);
 	struct buffer_head *bh = NULL;
-	struct udf_part_map *partmap;
 	unsigned long block;
 	unsigned long block_group;
 	unsigned long bit;
@@ -138,19 +132,9 @@ static void udf_bitmap_free_blocks(struct super_block *sb,
 	unsigned long overflow;
 
 	mutex_lock(&sbi->s_alloc_mutex);
-	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
-	if (bloc->logicalBlockNum + count < count ||
-	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
-		udf_debug("%u < %d || %u + %u > %u\n",
-			  bloc->logicalBlockNum, 0,
-			  bloc->logicalBlockNum, count,
-			  partmap->s_partition_len);
-		goto error_return;
-	}
-
+	/* We make sure this cannot overflow when mounting the filesystem */
 	block = bloc->logicalBlockNum + offset +
 		(sizeof(struct spaceBitmapDesc) << 3);
-
 	do {
 		overflow = 0;
 		block_group = block >> (sb->s_blocksize_bits + 3);
@@ -380,7 +364,6 @@ static void udf_table_free_blocks(struct super_block *sb,
 				  uint32_t count)
 {
 	struct udf_sb_info *sbi = UDF_SB(sb);
-	struct udf_part_map *partmap;
 	uint32_t start, end;
 	uint32_t elen;
 	struct kernel_lb_addr eloc;
@@ -389,16 +372,6 @@ static void udf_table_free_blocks(struct super_block *sb,
 	struct udf_inode_info *iinfo;
 
 	mutex_lock(&sbi->s_alloc_mutex);
-	partmap = &sbi->s_partmaps[bloc->partitionReferenceNum];
-	if (bloc->logicalBlockNum + count < count ||
-	    (bloc->logicalBlockNum + count) > partmap->s_partition_len) {
-		udf_debug("%u < %d || %u + %u > %u\n",
-			  bloc->logicalBlockNum, 0,
-			  bloc->logicalBlockNum, count,
-			  partmap->s_partition_len);
-		goto error_return;
-	}
-
 	iinfo = UDF_I(table);
 	udf_add_free_space(sb, sbi->s_partition, count);
 
@@ -673,6 +646,17 @@ void udf_free_blocks(struct super_block *sb, struct inode *inode,
 {
 	uint16_t partition = bloc->partitionReferenceNum;
 	struct udf_part_map *map = &UDF_SB(sb)->s_partmaps[partition];
+	uint32_t blk;
+
+	if (check_add_overflow(bloc->logicalBlockNum, offset, &blk) ||
+	    check_add_overflow(blk, count, &blk) ||
+	    bloc->logicalBlockNum + count > map->s_partition_len) {
+		udf_debug("Invalid request to free blocks: (%d, %u), off %u, "
+			  "len %u, partition len %u\n",
+			  partition, bloc->logicalBlockNum, offset, count,
+			  map->s_partition_len);
+		return;
+	}
 
 	if (map->s_partition_flags & UDF_PART_FLAG_UNALLOC_BITMAP) {
 		udf_bitmap_free_blocks(sb, map->s_uspace.s_bitmap,