From: Seth Forshee <seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> To: "Eric W. Biederman" <ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>, Paul Moore <paul-r2n+y4ga6xFZroRs9YW3xA@public.gmane.org>, Stephen Smalley <sds-+05T5uksL2qpZYMLLGbcSA@public.gmane.org>, Eric Paris <eparis-FjpueFixGhCM4zKIHC2jIg@public.gmane.org> Cc: linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Serge Hallyn <serge.hallyn-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>, Seth Forshee <seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>, James Morris <james.l.morris-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Miklos Szeredi <mszeredi-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-raid-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, fuse-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Austin S Hemmelgarn <ahferroin7-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Alexander Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>, selinux-+05T5uksL2qpZYMLLGbcSA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Pavel Tikhomirov <ptikhomirov-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org>, "Serge E. Hallyn" <serge-A9i7LUbDfNHQT0dZR+AlfA@public.gmane.org> Subject: [PATCH v4 07/21] selinux: Add support for unprivileged mounts from user namespaces Date: Tue, 26 Apr 2016 14:36:20 -0500 [thread overview] Message-ID: <1461699396-33000-8-git-send-email-seth.forshee@canonical.com> (raw) In-Reply-To: <1461699396-33000-1-git-send-email-seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> Security labels from unprivileged mounts in user namespaces must be ignored. Force superblocks from user namespaces whose labeling behavior is to use xattrs to use mountpoint labeling instead. For the mountpoint label, default to converting the current task context into a form suitable for file objects, but also allow the policy writer to specify a different label through policy transition rules. Pieced together from code snippets provided by Stephen Smalley. Signed-off-by: Seth Forshee <seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> Acked-by: Stephen Smalley <sds-+05T5uksL2qpZYMLLGbcSA@public.gmane.org> Acked-by: James Morris <james.l.morris-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org> --- security/selinux/hooks.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 1350167635cb..33beed3ac589 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -820,6 +820,28 @@ static int selinux_set_mnt_opts(struct super_block *sb, goto out; } } + + /* + * If this is a user namespace mount, no contexts are allowed + * on the command line and security labels must be ignored. + */ + if (sb->s_user_ns != &init_user_ns) { + if (context_sid || fscontext_sid || rootcontext_sid || + defcontext_sid) { + rc = -EACCES; + goto out; + } + if (sbsec->behavior == SECURITY_FS_USE_XATTR) { + sbsec->behavior = SECURITY_FS_USE_MNTPOINT; + rc = security_transition_sid(current_sid(), current_sid(), + SECCLASS_FILE, NULL, + &sbsec->mntpoint_sid); + if (rc) + goto out; + } + goto out_set_opts; + } + /* sets the context of the superblock for the fs being mounted. */ if (fscontext_sid) { rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); @@ -888,6 +910,7 @@ static int selinux_set_mnt_opts(struct super_block *sb, sbsec->def_sid = defcontext_sid; } +out_set_opts: rc = sb_finish_set_opts(sb); out: mutex_unlock(&sbsec->lock); -- 2.7.4 ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z -- fuse-devel mailing list To unsubscribe or subscribe, visit https://lists.sourceforge.net/lists/listinfo/fuse-devel
WARNING: multiple messages have this Message-ID (diff)
From: Seth Forshee <seth.forshee@canonical.com> To: "Eric W. Biederman" <ebiederm@xmission.com>, Paul Moore <paul@paul-moore.com>, Stephen Smalley <sds@tycho.nsa.gov>, Eric Paris <eparis@parisplace.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk>, Serge Hallyn <serge.hallyn@canonical.com>, Richard Weinberger <richard.weinberger@gmail.com>, Austin S Hemmelgarn <ahferroin7@gmail.com>, Miklos Szeredi <mszeredi@redhat.com>, Pavel Tikhomirov <ptikhomirov@virtuozzo.com>, linux-kernel@vger.kernel.org, linux-bcache@vger.kernel.org, dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-mtd@lists.infradead.org, linux-fsdevel@vger.kernel.org, fuse-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov, cgroups@vger.kernel.org, Seth Forshee <seth.forshee@canonical.com>, James Morris <james.l.morris@oracle.com>, "Serge E. Hallyn" <serge@hallyn.com> Subject: [PATCH v4 07/21] selinux: Add support for unprivileged mounts from user namespaces Date: Tue, 26 Apr 2016 14:36:20 -0500 [thread overview] Message-ID: <1461699396-33000-8-git-send-email-seth.forshee@canonical.com> (raw) In-Reply-To: <1461699396-33000-1-git-send-email-seth.forshee@canonical.com> Security labels from unprivileged mounts in user namespaces must be ignored. Force superblocks from user namespaces whose labeling behavior is to use xattrs to use mountpoint labeling instead. For the mountpoint label, default to converting the current task context into a form suitable for file objects, but also allow the policy writer to specify a different label through policy transition rules. Pieced together from code snippets provided by Stephen Smalley. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: James Morris <james.l.morris@oracle.com> --- security/selinux/hooks.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 1350167635cb..33beed3ac589 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -820,6 +820,28 @@ static int selinux_set_mnt_opts(struct super_block *sb, goto out; } } + + /* + * If this is a user namespace mount, no contexts are allowed + * on the command line and security labels must be ignored. + */ + if (sb->s_user_ns != &init_user_ns) { + if (context_sid || fscontext_sid || rootcontext_sid || + defcontext_sid) { + rc = -EACCES; + goto out; + } + if (sbsec->behavior == SECURITY_FS_USE_XATTR) { + sbsec->behavior = SECURITY_FS_USE_MNTPOINT; + rc = security_transition_sid(current_sid(), current_sid(), + SECCLASS_FILE, NULL, + &sbsec->mntpoint_sid); + if (rc) + goto out; + } + goto out_set_opts; + } + /* sets the context of the superblock for the fs being mounted. */ if (fscontext_sid) { rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); @@ -888,6 +910,7 @@ static int selinux_set_mnt_opts(struct super_block *sb, sbsec->def_sid = defcontext_sid; } +out_set_opts: rc = sb_finish_set_opts(sb); out: mutex_unlock(&sbsec->lock); -- 2.7.4
next prev parent reply other threads:[~2016-04-26 19:36 UTC|newest] Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-04-26 19:36 [PATCH v4 00/21] Support fuse mounts in user namespaces Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 01/21] fs: fix a posible leak of allocated superblock Seth Forshee 2016-04-26 19:36 ` [PATCH v4 04/21] block_dev: Support checking inode permissions in lookup_bdev() Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 05/21] block_dev: Check permissions towards block device inode when mounting Seth Forshee 2016-04-26 19:36 ` [PATCH v4 06/21] fs: Treat foreign mounts as nosuid Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 08/21] userns: Replace in_userns with current_in_userns Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 09/21] Smack: Handle labels consistently in untrusted mounts Seth Forshee 2016-04-26 19:36 ` [PATCH v4 10/21] fs: Check for invalid i_uid in may_follow_link() Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-05-24 15:55 ` Djalal Harouni 2016-04-26 19:36 ` [PATCH v4 11/21] cred: Reject inodes with invalid ids in set_create_file_as() Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 15/21] fs: Don't remove suid for CAP_FSETID in s_user_ns Seth Forshee 2016-04-26 19:36 ` Seth Forshee [not found] ` <1461699396-33000-1-git-send-email-seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> 2016-04-26 19:36 ` [PATCH v4 02/21] fs: Remove check of s_user_ns for existing mounts in fs_fully_visible() Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 03/21] fs: Allow sysfs and cgroupfs to share super blocks between user namespaces Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` Seth Forshee [this message] 2016-04-26 19:36 ` [PATCH v4 07/21] selinux: Add support for unprivileged mounts from " Seth Forshee 2016-04-26 19:36 ` [PATCH v4 12/21] fs: Refuse uid/gid changes which don't map into s_user_ns Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 13/21] fs: Update posix_acl support to handle user namespace mounts Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 14/21] fs: Allow superblock owner to change ownership of inodes with unmappable ids Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 16/21] fs: Allow superblock owner to access do_remount_sb() Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 17/21] capabilities: Allow privileged user in s_user_ns to set security.* xattrs Seth Forshee 2016-04-26 19:36 ` Seth Forshee [not found] ` <1461699396-33000-18-git-send-email-seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> 2016-04-27 7:22 ` James Morris 2016-04-27 7:22 ` James Morris 2016-04-26 19:36 ` [PATCH v4 18/21] fuse: Add support for pid namespaces Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-07-20 2:44 ` Sheng Yang [not found] ` <CA+2rt426_pshAauQizcxkfAq16vmEpB4sJ4genW_ucosH3j=zQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2016-07-20 12:52 ` Seth Forshee 2016-07-20 12:52 ` Seth Forshee 2016-07-20 22:28 ` Sheng Yang 2016-07-21 7:25 ` Miklos Szeredi 2016-07-21 7:25 ` Miklos Szeredi 2016-04-26 19:36 ` [PATCH v4 19/21] fuse: Support fuse filesystems outside of init_user_ns Seth Forshee 2016-04-26 19:36 ` Seth Forshee 2016-04-26 19:36 ` [PATCH v4 20/21] fuse: Restrict allow_other to the superblock's namespace or a descendant Seth Forshee 2016-04-26 19:36 ` [PATCH v4 21/21] fuse: Allow user namespace mounts Seth Forshee
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