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>
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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
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next prev 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
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