From: ebiederm@xmission.com (Eric W. Biederman)
To: "Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-kernel@vger.kernel.org,
Linux Containers <containers@lists.linux-foundation.org>,
Cyrill Gorcunov <gorcunov@openvz.org>,
linux-security-module@vger.kernel.org,
Al Viro <viro@ZenIV.linux.org.uk>,
linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 27/43] userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs
Date: Wed, 25 Apr 2012 22:33:06 -0700 [thread overview]
Message-ID: <m1wr53f46l.fsf@fess.ebiederm.org> (raw)
In-Reply-To: <20120426001101.GA10308@mail.hallyn.com> (Serge E. Hallyn's message of "Thu, 26 Apr 2012 00:11:01 +0000")
"Serge E. Hallyn" <serge@hallyn.com> writes:
> Quoting Eric W. Biederman (ebiederm@xmission.com):
>> "Serge E. Hallyn" <serge@hallyn.com> writes:
>>
>> > Quoting Eric W. Beiderman (ebiederm@xmission.com):
>> >> From: Eric W. Biederman <ebiederm@xmission.com>
>> >>
>> >> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
>> >> ---
>> >> fs/attr.c | 8 ++++----
>> >> fs/exec.c | 10 +++++-----
>> >> fs/fcntl.c | 6 +++---
>> >> fs/ioprio.c | 4 ++--
>> >> fs/locks.c | 2 +-
>> >> fs/namei.c | 8 ++++----
>> >> include/linux/quotaops.h | 4 ++--
>> >> 7 files changed, 21 insertions(+), 21 deletions(-)
>> >>
>>
>> >> @@ -2120,7 +2120,7 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs)
>> >> if (__get_dumpable(cprm.mm_flags) == 2) {
>> >> /* Setuid core dump mode */
>> >> flag = O_EXCL; /* Stop rewrite attacks */
>> >> - cred->fsuid = 0; /* Dump root private */
>> >> + cred->fsuid = GLOBAL_ROOT_UID; /* Dump root private */
>> >
>> > Sorry, one more - can this be the per-ns root uid? The coredumps should
>> > be ok to belong to privileged users in the namespace right?
>>
>> I'm not certain it was clear when you were looking at this that
>> this is about dumping core from suid applications, not normal
>> applications.
>>
>> Looking at the code in commoncap and commit_creds it looks like it is a
>> bug that we don't call set_dumpable(new, suid_dumpable) in common cap
>> when we use file capabilities. I might be wrong but I think we escape
>
> We do, check kernel/cred.c:commit_creds(). So long as the new permitted
> set is not a subset of the old one.
>
> Tested it to make absolutely sure. When I add file capabilities to a
> program that otherwise dumps core (int *x = 0; *x = 0;), core dumps are
> no longer generated.
Thanks for testing. Just reading through I was not certain if we had
the change in creds that commit_creds needed to trigger the set_dumpable
logic.
Eric
next prev parent reply other threads:[~2012-04-26 5:29 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-08 5:10 [REVIEW][PATCH 0/43] Completing the user namespace Eric W. Biederman
2012-04-08 5:14 ` [PATCH 01/43] vfs: Don't allow a user namespace root to make device nodes "Eric W. Beiderman
2012-04-08 5:14 ` [PATCH 02/43] userns: Kill bogus declaration of function release_uids "Eric W. Beiderman
2012-04-08 5:14 ` [PATCH 03/43] userns: Replace netlink uses of cap_raised with capable "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 04/43] userns: Remove unnecessary cast to struct user_struct when copying cred->user "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 05/43] cred: Add forward declaration of init_user_ns in all cases "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 06/43] userns: Use cred->user_ns instead of cred->user->user_ns "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 07/43] cred: Refcount the user_ns pointed to by the cred "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 08/43] userns: Add an explicit reference to the parent user namespace "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 09/43] mqueue: Explicitly capture the user namespace to send the notification to "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 10/43] userns: Deprecate and rename the user_namespace reference in the user_struct "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 11/43] userns: Start out with a full set of capabilities "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 12/43] userns: Replace the hard to write inode_userns with inode_capable "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 13/43] userns: Add kuid_t and kgid_t and associated infrastructure in uidgid.h "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 14/43] userns: Add a Kconfig option to enforce strict kuid and kgid type checks "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 15/43] userns: Disassociate user_struct from the user_namespace "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 16/43] userns: Simplify the user_namespace by making userns->creator a kuid "Eric W. Beiderman
2012-04-18 18:48 ` Serge E. Hallyn
2012-04-20 22:58 ` Eric W. Biederman
2012-04-24 17:33 ` Serge E. Hallyn
2012-04-24 19:41 ` Eric W. Biederman
2012-04-24 20:23 ` Serge E. Hallyn
2012-04-26 9:09 ` Eric W. Biederman
2012-04-26 16:21 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 18/43] userns: Convert group_info values from gid_t to kgid_t "Eric W. Beiderman
2012-04-18 18:49 ` Serge E. Hallyn
2012-04-20 23:05 ` Eric W. Biederman
2012-04-08 5:15 ` [PATCH 19/43] userns: Store uid and gid values in struct cred with kuid_t and kgid_t types "Eric W. Beiderman
2012-04-18 18:49 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 20/43] userns: Replace user_ns_map_uid and user_ns_map_gid with from_kuid and from_kgid "Eric W. Beiderman
2012-04-18 18:49 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 21/43] userns: Convert sched_set_affinity and sched_set_scheduler's permission checks "Eric W. Beiderman
2012-04-18 18:50 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 22/43] userns: Convert capabilities related permsion checks "Eric W. Beiderman
2012-04-18 18:51 ` Serge E. Hallyn
2012-04-20 23:18 ` Eric W. Biederman
2012-04-08 5:15 ` [PATCH 23/43] userns: Convert setting and getting uid and gid system calls to use kuid and kgid "Eric W. Beiderman
2012-04-26 16:20 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 24/43] userns: Convert ptrace, kill, set_priority permission checks to work with kuids and kgids "Eric W. Beiderman
2012-04-18 18:56 ` Serge E. Hallyn
2012-04-20 23:51 ` Eric W. Biederman
2012-04-08 5:15 ` [PATCH 25/43] userns: Store uid and gid types in vfs structures with kuid_t and kgid_t types "Eric W. Beiderman
2012-04-18 18:57 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 26/43] userns: Convert in_group_p and in_egroup_p to use kgid_t "Eric W. Beiderman
2012-04-18 18:58 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 27/43] userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs "Eric W. Beiderman
2012-04-18 19:02 ` Serge E. Hallyn
2012-04-21 0:05 ` Eric W. Biederman
2012-04-18 19:03 ` Serge E. Hallyn
2012-04-21 0:58 ` Eric W. Biederman
2012-04-24 17:41 ` Serge E. Hallyn
2012-04-26 0:11 ` Serge E. Hallyn
2012-04-26 5:33 ` Eric W. Biederman [this message]
2012-04-08 5:15 ` [PATCH 28/43] userns: Convert user specfied uids and gids in chown into kuids and kgid "Eric W. Beiderman
2012-04-18 19:03 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 29/43] userns: Convert stat to return values mapped from kuids and kgids "Eric W. Beiderman
2012-04-18 19:03 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 30/43] userns: Fail exec for suid and sgid binaries with ids outside our user namespace "Eric W. Beiderman
2012-04-18 19:05 ` Serge E. Hallyn
2012-04-18 19:09 ` Serge E. Hallyn
2012-04-24 2:28 ` Eric W. Biederman
2012-04-24 15:10 ` Serge Hallyn
2012-04-08 5:15 ` [PATCH 31/43] userns: Teach inode_capable to understand inodes whose uids map to other namespaces "Eric W. Beiderman
2012-04-18 19:06 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 32/43] userns: signal remove unnecessary map_cred_ns "Eric W. Beiderman
2012-04-18 19:07 ` Serge E. Hallyn
2012-04-08 5:15 ` [PATCH 33/43] userns: Convert binary formats to use kuid/kgid where appropriate "Eric W. Beiderman
2012-04-18 19:10 ` Serge E. Hallyn
2012-04-24 2:44 ` Eric W. Biederman
2012-04-08 5:15 ` [PATCH 34/43] userns: Convert devpts " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 35/43] userns: Convert ext2 " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 36/43] userns: Convert ext3 " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 37/43] userns: Convert ext4 to user " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 38/43] userns: Convert proc to use " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 39/43] userns: Convert sysctl permission checks to use kuid and kgids "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 40/43] userns: Convert sysfs to use kgid/kuid where appropriate "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 41/43] userns: Convert tmpfs to use kuid and kgid " "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 42/43] userns: Convert cgroup permission checks to use uid_eq "Eric W. Beiderman
2012-04-08 5:15 ` [PATCH 43/43] userns: Convert the move_pages, and migrate_pages " "Eric W. Beiderman
2012-04-08 14:54 ` [REVIEW][PATCH 0/43] Completing the user namespace Serge Hallyn
2012-04-08 17:40 ` richard -rw- weinberger
2012-04-08 21:30 ` Eric W. Biederman
2012-04-08 22:04 ` richard -rw- weinberger
2012-04-08 22:52 ` Eric W. Biederman
[not found] ` <1333862139-31737-17-git-send-email-ebiederm@xmission.com>
2012-04-18 18:49 ` [PATCH 17/43] userns: Rework the user_namespace adding uid/gid mapping support Serge E. Hallyn
2012-05-11 23:20 ` Please include user-namespace.git in linux-next Eric W. Biederman
2012-05-13 23:35 ` Stephen Rothwell
2012-05-21 2:25 ` Tetsuo Handa
2012-05-22 17:26 ` Eric W. Biederman
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=m1wr53f46l.fsf@fess.ebiederm.org \
--to=ebiederm@xmission.com \
--cc=akpm@linux-foundation.org \
--cc=containers@lists.linux-foundation.org \
--cc=gorcunov@openvz.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=serge@hallyn.com \
--cc=torvalds@linux-foundation.org \
--cc=viro@ZenIV.linux.org.uk \
/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