lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:	Mon, 10 Dec 2012 23:17:24 +0800
From:	Tao Ma <>
To:	Theodore Ts'o <>
Subject: Re: [PATCH V7 00/23] ext4: Add inline data support

On 12/10/2012 11:02 PM, Theodore Ts'o wrote:
> On Fri, Dec 07, 2012 at 09:34:24AM +0800, Tao Ma wrote:
>> I think ext4_inode->xattr_sem should protect us? When we do xattr
>> corresponding operation, we just do
>> down_write/read(&EXT4_I(inode)->xattr_sem), so we should be fine with
>> this type of operation. Am I missing something here?
> We're not taking the xattr_sem in ext4_find_inline_data() before we
> call ext4_xattr_ibody_find().  So I think we need something like this:
> diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
> index 6b600b4..e96268d 100644
> --- a/fs/ext4/inline.c
> +++ b/fs/ext4/inline.c
> @@ -143,7 +143,9 @@ int ext4_find_inline_data(struct inode *inode)
>  	if (error)
>  		return error;
> +	down_read(&EXT4_I(inode)->xattr_sem);
>  	error = ext4_xattr_ibody_find(inode, &i, &is);
> +	up_read(&EXT4_I(inode)->xattr_sem);
>  	if (error)
>  		goto out;
Actually ext4_find_inline_data is only called in ext4_iget when we
initialize an inode from the disk and that's the reason why I didn't add
this lock. So maybe the name isn't obvious to the reader.  :(

Having said that, I think it should be safe for us to add this lock so
that any future user may abuse it without any worry about the xattr
lock. So go ahead with it.

To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to
More majordomo info at

Powered by blists - more mailing lists