4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara <jack@xxxxxxx> [ Upstream commit ebbe26fd54a9621994bc16b14f2ba8f84c089693 ] 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@xxxxxxx Signed-off-by: Jan Kara <jack@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- fs/udf/super.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/fs/udf/super.c b/fs/udf/super.c index 6273ffd312cc..22c76a33f6f3 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1054,12 +1054,19 @@ 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; @@ -1115,6 +1122,14 @@ 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); } -- 2.43.0
