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.
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/udf/super.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
I plan to merge this patch through my tree.
diff --git a/fs/udf/super.c b/fs/udf/super.c
index 9381a66c6ce5..c7bdda3f9369 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1110,12 +1110,19 @@ 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;
@@ -1171,6 +1178,14 @@ 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 it too long (%u)\n", p_index,
+ map->s_partition_len);
+ return -EFSCORRUPTED;
+ }
udf_debug("unallocSpaceBitmap (part %d) @ %u\n",
p_index, bitmap->s_extPosition);
}
--
2.35.3
