From: Jan Kara jack@suse.cz
[ 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@suse.cz Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Sasha Levin sashal@kernel.org --- fs/udf/super.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/fs/udf/super.c b/fs/udf/super.c index 928a04d9d9e0a..9416aca543a85 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1079,12 +1079,19 @@ 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; @@ -1140,6 +1147,14 @@ 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); }