Linux ext4: Out-of-bounds Memcpy via Non-Inline system.data xattr

In Summary :

ext4 can store data for small regular files as "inline data", meaning that the data is stored inside the 

corresponding inode instead of in separate blocks. Inline data is stored in two places: The first 60 

bytes go in the i_block field in the inode (which normally contains a list of blocks instead), the rest 

goes in the special filesystem-internal extended attribute "system.data". Since commit e50e5129f384

 ("ext4: xattr-in-inode support", in v4.13+), ext4 can store extended attribute values not only inline in 

the inode, but can also store such values in dedicated inodes. When a corrupted filesystem stores the 

system.data extended attribute value in a dedicated inode, the kernel gets confused, causing memory

 corruption.[...]

kindly refer the following link as follow up :
https://ift.tt/2IHZzd7