Re: [PATCH V3] ocfs2: pass u64 to ocfs2_truncate_inline maybe overflow

[Joseph Qi]

On 10/16/24 11:22 AM, Edward Adam Davis wrote:
> Syzbot reported a kernel BUG in ocfs2_truncate_inline.
> There are two reasons for this: first, the parameter value passed is greater
> than UINT_MAX, second, the start and end parameters of ocfs2_truncate_inline
> are "unsigned int".
> 
> So, we need to add a sanity check for byte_start and byte_len right before
> ocfs2_truncate_inline() in ocfs2_remove_inode_range(), if they are greater
> than ocfs2_max_inline_data_with_xattr return -EFBIG.
> 
> Reported-by: syzbot+81092778aac03460d6b7@xxxxxxxxxxxxxxxxxxxxxxxxx
> Closes: https://syzkaller.appspot.com/bug?extid=81092778aac03460d6b7
> Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>
> ---
> V1 -> V2: move sanity check to ocfs2_remove_inode_range
> V2 -> V3: use ocfs2_max_inline_data_with_xattr return value replace UINT_MAX
> 
>  fs/ocfs2/file.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index ad131a2fc58e..9327aa2f1bf4 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1784,6 +1784,12 @@ int ocfs2_remove_inode_range(struct inode *inode,
>  		return 0;
>  
>  	if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
> +		int max_inl = ocfs2_max_inline_data_with_xattr(inode->i_sb, di);

Or rename it to 'id_count' refer to 'struct ocfs2_inline_data'.
Better to leave a blank line here.

> +		if (byte_start > max_inl || byte_start + byte_len > max_inl) {
> +			ret = -EFBIG;

Seems 'EINVAL' is more proper here.
Please do corresponding change in commit log.

> +			mlog_errno(ret);
> +			goto out;
> +		}

Better to leave a blank line.

Thanks,
Joseph

>  		ret = ocfs2_truncate_inline(inode, di_bh, byte_start,
>  					    byte_start + byte_len, 0);
>  		if (ret) {