On 2023/01/03 5:19, Michal Hocko wrote:
>> @@ -52,7 +52,7 @@ int ntfs_load_attr_list(struct ntfs_inode *ni, struct ATTRIB *attr)
>>
>> if (!attr->non_res) {
>> lsize = le32_to_cpu(attr->res.data_size);
>> - le = kmalloc(al_aligned(lsize), GFP_NOFS);
>> + le = kmalloc(al_aligned(lsize), GFP_NOFS | __GFP_NOWARN);
>
> This looks like a bad idea in general. The allocator merely says that
> something is wrong and you are silencing that. The calling code should
> check the size for reasonable range and if larger size. Moreover, if
> lsize can be really more than PAGE_SIZE this should be kvmalloc instead.
There are already similar commits.
commit 0d0f659bf713 ("fs/ntfs3: Use __GFP_NOWARN allocation at wnd_init()")
commit 59bfd7a483da ("fs/ntfs3: Use __GFP_NOWARN allocation at ntfs_fill_super()")
Is KMALLOC_MAX_SIZE intended to be used by callers like
https://linux.googlesource.com/linux/kernel/git/torvalds/linux/+/a5a1e1f249db4e0a35d3deca0b9916b11cc1f02b%5E!
? I think that, unless there is a known upper limit defined by specification,
checking for overflow and silence like
https://lkml.kernel.org/r/6d878e01-6c2f-8766-2578-c95030442369@xxxxxxxxxxxxxxxxxxx
is fine. These input are random values which do not need to succeed by using kvmalloc().
