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udf: Avoid excessive partition lengths

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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>
This commit is contained in:
Jan Kara 2024-06-20 12:52:17 +02:00
parent 8037da38d3
commit ebbe26fd54
1 changed files with 15 additions and 0 deletions
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15
fs/udf/super.c
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@ -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);
}