Commit ebbe26fd authored by Jan Kara's avatar Jan Kara
Browse files

udf: Avoid excessive partition lengths 

Avoid mounting filesystems where the partition would overflow the
32-bits used for block number. Also refuse to mount filesystems where
the partition length is so large we cannot safely index bits in a
block bitmap.

Link: https://patch.msgid.link/20240620130403.14731-1-jack@suse.cz


Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 8037da38

fs/udf/super.c

+15 −0
Original line number Diff line number Diff line
@@ -1111,12 +1111,19 @@ static int udf_fill_partdesc_info(struct super_block *sb, 
	struct udf_part_map *map;

	struct udf_sb_info *sbi = UDF_SB(sb);

	struct partitionHeaderDesc *phd;

	u32 sum;

	int err;



	map = &sbi->s_partmaps[p_index];



	map->s_partition_len = le32_to_cpu(p->partitionLength); /* blocks */

	map->s_partition_root = le32_to_cpu(p->partitionStartingLocation);

	if (check_add_overflow(map->s_partition_root, map->s_partition_len,

			       &sum)) {

		udf_err(sb, "Partition %d has invalid location %u + %u\n",

			p_index, map->s_partition_root, map->s_partition_len);

		return -EFSCORRUPTED;

	}



	if (p->accessType == cpu_to_le32(PD_ACCESS_TYPE_READ_ONLY))

		map->s_partition_flags |= UDF_PART_FLAG_READ_ONLY;
@@ -1172,6 +1179,14 @@ static int udf_fill_partdesc_info(struct super_block *sb, 
		bitmap->s_extPosition = le32_to_cpu(

				phd->unallocSpaceBitmap.extPosition);

		map->s_partition_flags |= UDF_PART_FLAG_UNALLOC_BITMAP;

		/* Check whether math over bitmap won't overflow. */

		if (check_add_overflow(map->s_partition_len,

				       sizeof(struct spaceBitmapDesc) << 3,

				       &sum)) {

			udf_err(sb, "Partition %d is too long (%u)\n", p_index,

				map->s_partition_len);

			return -EFSCORRUPTED;

		}

		udf_debug("unallocSpaceBitmap (part %d) @ %u\n",

			  p_index, bitmap->s_extPosition);

	}