linux-kernel - Re: [PATCH -V1 09/22] vfs: Make acl_permission

lists.openwall.net		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] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140429002013.GR15995@dastard>
Date:	Tue, 29 Apr 2014 10:20:13 +1000
From:	Dave Chinner <david@...morbit.com>
To:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Cc:	agruen@...nel.org, bfields@...ldses.org, akpm@...ux-foundation.org,
	viro@...iv.linux.org.uk, dhowells@...hat.com,
	linux-fsdevel@...r.kernel.org, linux-nfs@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH -V1 09/22] vfs: Make acl_permission_check() work for
 richacls

On Sun, Apr 27, 2014 at 09:44:40PM +0530, Aneesh Kumar K.V wrote:
> From: Andreas Gruenbacher <agruen@...nel.org>
> 
> Signed-off-by: Andreas Gruenbacher <agruen@...nel.org>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@...ux.vnet.ibm.com>
> ---
>  fs/namei.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/fs/namei.c b/fs/namei.c
> index 26b9a8212837..06474553c08d 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -284,6 +284,19 @@ static int acl_permission_check(struct inode *inode, int mask)
>  {
>  	unsigned int mode = inode->i_mode;
>  
> +	if (IS_RICHACL(inode)) {
> +		int error = check_acl(inode, mask);
> +		if (error != -EAGAIN)
> +			return error;
> +		if (mask & (MAY_DELETE_SELF | MAY_TAKE_OWNERSHIP |
> +			    MAY_CHMOD | MAY_SET_TIMES)) {
> +			/*
> +			 * The file permission bit cannot grant these
> +			 * permissions.
> +			 */
> +			return -EACCES;
> +		}
> +	}
>  	if (likely(uid_eq(current_fsuid(), inode->i_uid)))
>  		mode >>= 6;
>  	else {

why does this take priority over a simple uid match? Some comments
explaining this for people unfamiliar with richacls would be nice.
Not to mention the commit message should also explain the change...

Cheers,

Dave.
-- 
Dave Chinner
david@...morbit.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/