linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: NeilBrown <neilb@suse.com>
To: Thiago Rafael Becker <thiago.becker@gmail.com>, bfields@fieldses.org
Cc: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Thiago Rafael Becker <thiago.becker@gmail.com>
Subject: Re: [PATCH 2/3, V2] kernel: Move groups_sort to the caller of set_groups.
Date: Mon, 04 Dec 2017 12:42:46 +1100	[thread overview]
Message-ID: <87mv2ztgix.fsf@notabene.neil.brown.name> (raw)
In-Reply-To: <20171130130457.11429-3-thiago.becker@gmail.com>

[-- Attachment #1: Type: text/plain, Size: 2656 bytes --]

On Thu, Nov 30 2017, Thiago Rafael Becker wrote:

> The responsibility for calling groups_sort is now on the caller
> of set_groups.
>
> Signed-off-by: Thiago Rafael Becker <thiago.becker@gmail.com>
> ---
>  kernel/groups.c           | 1 +
>  kernel/uid16.c            | 1 +
>  net/sunrpc/svcauth_unix.c | 7 +++++++
>  3 files changed, 9 insertions(+)
>
> diff --git a/kernel/groups.c b/kernel/groups.c
> index 4c9c9ed..17073a9 100644
> --- a/kernel/groups.c
> +++ b/kernel/groups.c
> @@ -208,6 +208,7 @@ SYSCALL_DEFINE2(setgroups, int, gidsetsize, gid_t __user *, grouplist)
>  		return retval;
>  	}
>  
> +	groups_sort(group_info);
>  	retval = set_current_groups(group_info);
>  	put_group_info(group_info);
>  
> diff --git a/kernel/uid16.c b/kernel/uid16.c
> index ce74a49..ef1da2a 100644
> --- a/kernel/uid16.c
> +++ b/kernel/uid16.c
> @@ -192,6 +192,7 @@ SYSCALL_DEFINE2(setgroups16, int, gidsetsize, old_gid_t __user *, grouplist)
>  		return retval;
>  	}
>  
> +	groups_sort(group_info);
>  	retval = set_current_groups(group_info);
>  	put_group_info(group_info);
>  
> diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
> index f81eaa8..91e3d34 100644
> --- a/net/sunrpc/svcauth_unix.c
> +++ b/net/sunrpc/svcauth_unix.c
> @@ -20,6 +20,7 @@
>  
>  
>  #include "netns.h"
> +void groups_sort(struct group_info *group_info);
>  
>  /*
>   * AUTHUNIX and AUTHNULL credentials are both handled here.
> @@ -520,6 +521,12 @@ static int unix_gid_parse(struct cache_detail *cd,
>  		ug.gi->gid[i] = kgid;
>  	}
>  
> +	/* Sort the groups before inserting this entry
> +	 * into the cache to avoid future corrutpions
> +	 * by multiple simultaneous attempts to sort this
> +	 * entry.
> +	 */
> +	groups_sort(ug.gi);
>  	ugp = unix_gid_lookup(cd, uid);
>  	if (ugp) {
>  		struct cache_head *ch;


I think you need to add groups_sort() in a few more places.
Almost anywhere that calls groups_alloc() should be considered.
net/sunrpc/svcauth_unix.c, net/sunrpc/auth_gss/svcauth_gss.c,
fs/nfsd/auth.c definitely need it.

I wonder if there is a more robust way to fix this.
Maybe:
  groups_alloc() could initialize ->usage to -1
  groups_sort() to require it be -1, and change it to 1
  get_group_info() complains if ->usage is -1 ???

or something.
Maybe it could be done with types.
'struct group_info' could be declared with ngroups and
gid[] as const.
'struct group_info_unsorted' could be the same structure but
without the 'const'.
Then groups_sort() takes a 'struct group_info_unsorted *' and returns
a 'struct group_info *'...

Thanks,
NeilBrown

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]

  parent reply	other threads:[~2017-12-04  1:42 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-30 13:04 [PATCH 0/3, V2] Move groups_sort outisde of set_groups Thiago Rafael Becker
2017-11-30 13:04 ` [PATCH 1/3, V2] kernel: make groups_sort globally visible Thiago Rafael Becker
2017-11-30 13:04 ` [PATCH 2/3, V2] kernel: Move groups_sort to the caller of set_groups Thiago Rafael Becker
2017-12-03 12:56   ` kbuild test robot
2017-12-04  1:42   ` NeilBrown [this message]
2017-12-04 15:39     ` Thiago Rafael Becker
2017-12-04 15:47       ` J. Bruce Fields
2017-12-04 19:00         ` Thiago Rafael Becker
2017-12-04 20:11       ` NeilBrown
2017-12-05 21:28         ` Matthew Wilcox
2017-12-05 22:05           ` NeilBrown
2017-12-05 23:03           ` Thiago Rafael Becker
2017-12-05 23:23             ` Matthew Wilcox
2017-12-19 16:30         ` J. Bruce Fields
2017-12-19 20:14           ` NeilBrown
2017-11-30 13:04 ` [PATCH 3/3, V2] kernel: set_groups doesn't call groups_sort anymore Thiago Rafael Becker
2017-12-05 14:05 ` [PATCH 0/3 v3] Move groups_sort outisde of set_groups Thiago Rafael Becker
2017-12-05 14:05   ` [PATCH 1/3 v3] kernel: make groups_sort globally visible Thiago Rafael Becker
2017-12-05 14:05   ` [PATCH 2/3 v3] kernel: Move groups_sort to the caller of set_groups Thiago Rafael Becker
2017-12-05 18:55     ` [PATCH 2/3] " Thiago Rafael Becker
2017-12-05 22:08       ` NeilBrown
2017-12-05 18:57     ` [PATCH 2/3 v3] " Thiago Rafael Becker
2017-12-05 14:05   ` [PATCH 3/3 v3] kernel: set_groups doesn't call groups_sort anymore Thiago Rafael Becker
2017-12-06 19:27   ` [PATCH 0/3 v3] Move groups_sort outisde of set_groups J. Bruce Fields
2017-12-11 13:28   ` [PATCH v4] kernel: make groups_sort calling a responsibility group_info allocators Thiago Rafael Becker
2017-12-11 14:27     ` Matthew Wilcox
2017-12-11 15:14       ` [PATCH v5] " Thiago Rafael Becker
2017-12-11 15:24         ` Matthew Wilcox
2017-12-11 16:18         ` J. Bruce Fields
2017-12-11 21:43         ` NeilBrown
2018-01-02 14:54         ` David Howells
2018-01-02 21:01           ` [PATCH] Documentation: security/credentials.rst: explain need to sort group_list NeilBrown
2018-01-02 21:04             ` Matthew Wilcox
2018-01-06 18:09               ` Jonathan Corbet
2018-01-06 20:20                 ` Matthew Wilcox
2018-01-06 22:36                   ` Randy Dunlap
2018-01-08 16:36                   ` Jonathan Corbet
2018-01-07 23:39                 ` NeilBrown
2018-01-08 16:40                   ` Jonathan Corbet

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87mv2ztgix.fsf@notabene.neil.brown.name \
    --to=neilb@suse.com \
    --cc=bfields@fieldses.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nfs@vger.kernel.org \
    --cc=thiago.becker@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).