[ 3.5.y.z extended stable ] Patch "proc: pid/status: show all supplementary groups" has been added to staging queue

[Herton Ronaldo Krzesinski]

This is a note to let you know that I have just added a patch titled

    proc: pid/status: show all supplementary groups

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From f8631261e301a4ed93a8a9a6d4a0b236c5577b9f Mon Sep 17 00:00:00 2001
From: Artem Bityutskiy <artem.bityutskiy at linux.intel.com>
Date: Mon, 17 Dec 2012 16:03:17 -0800
Subject: [PATCH] proc: pid/status: show all supplementary groups

commit 8d238027b87e654be552eabdf492042a34c5c300 upstream.

We display a list of supplementary group for each process in
/proc/<pid>/status.  However, we show only the first 32 groups, not all of
them.

Although this is rare, but sometimes processes do have more than 32
supplementary groups, and this kernel limitation breaks user-space apps
that rely on the group list in /proc/<pid>/status.

Number 32 comes from the internal NGROUPS_SMALL macro which defines the
length for the internal kernel "small" groups buffer.  There is no
apparent reason to limit to this value.

This patch removes the 32 groups printing limit.

The Linux kernel limits the amount of supplementary groups by NGROUPS_MAX,
which is currently set to 65536.  And this is the maximum count of groups
we may possibly print.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy at linux.intel.com>
Acked-by: Serge E. Hallyn <serge.hallyn at ubuntu.com>
Acked-by: Kees Cook <keescook at chromium.org>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at canonical.com>
---
 fs/proc/array.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/proc/array.c b/fs/proc/array.c
index c1c207c..bd31e02 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -212,7 +212,7 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
 	group_info = cred->group_info;
 	task_unlock(p);

-	for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++)
+	for (g = 0; g < group_info->ngroups; g++)
 		seq_printf(m, "%d ",
 			   from_kgid_munged(user_ns, GROUP_AT(group_info, g)));
 	put_cred(cred);
--
1.7.9.5