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Fri, 10 Dec 2021 19:47:39 +0000 (GMT) From: Stefan Berger To: linux-integrity@vger.kernel.org Cc: zohar@linux.ibm.com, serge@hallyn.com, christian.brauner@ubuntu.com, containers@lists.linux.dev, dmitry.kasatkin@gmail.com, ebiederm@xmission.com, krzysztof.struczynski@huawei.com, roberto.sassu@huawei.com, mpeters@redhat.com, lhinds@redhat.com, lsturman@redhat.com, puiterwi@redhat.com, jejb@linux.ibm.com, jamjoom@us.ibm.com, linux-kernel@vger.kernel.org, paul@paul-moore.com, rgb@redhat.com, linux-security-module@vger.kernel.org, jmorris@namei.org, Stefan Berger , James Bottomley Subject: [PATCH v6 11/17] securityfs: Only use simple_pin_fs/simple_release_fs for init_user_ns Date: Fri, 10 Dec 2021 14:47:30 -0500 Message-Id: <20211210194736.1538863-12-stefanb@linux.ibm.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211210194736.1538863-1-stefanb@linux.ibm.com> References: <20211210194736.1538863-1-stefanb@linux.ibm.com> MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: 87CusPLSDDIv-9HaBcL21yV1vuMhE7tp X-Proofpoint-GUID: EZaHEQ0-gjLZ54tKLN4NTTrFdbz3bhv8 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.790,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2021-12-10_07,2021-12-10_01,2021-12-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 suspectscore=0 clxscore=1015 mlxscore=0 malwarescore=0 spamscore=0 bulkscore=0 impostorscore=0 mlxlogscore=999 phishscore=0 adultscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2110150000 definitions=main-2112100106 Precedence: bulk List-ID: To prepare for virtualization of SecurityFS, use simple_pin_fs and simpe_release_fs only when init_user_ns is active. Signed-off-by: Stefan Berger Signed-off-by: James Bottomley Acked-by: Christian Brauner --- security/inode.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/security/inode.c b/security/inode.c index 6c326939750d..fee01ff4d831 100644 --- a/security/inode.c +++ b/security/inode.c @@ -21,9 +21,10 @@ #include #include #include +#include -static struct vfsmount *mount; -static int mount_count; +static struct vfsmount *init_securityfs_mount; +static int init_securityfs_mount_count; static void securityfs_free_inode(struct inode *inode) { @@ -109,6 +110,7 @@ static struct dentry *securityfs_create_dentry(const char *name, umode_t mode, const struct file_operations *fops, const struct inode_operations *iops) { + struct user_namespace *ns = current_user_ns(); struct dentry *dentry; struct inode *dir, *inode; int error; @@ -118,12 +120,19 @@ static struct dentry *securityfs_create_dentry(const char *name, umode_t mode, pr_debug("securityfs: creating file '%s'\n",name); - error = simple_pin_fs(&fs_type, &mount, &mount_count); - if (error) - return ERR_PTR(error); + if (ns == &init_user_ns) { + error = simple_pin_fs(&fs_type, &init_securityfs_mount, + &init_securityfs_mount_count); + if (error) + return ERR_PTR(error); + } - if (!parent) - parent = mount->mnt_root; + if (!parent) { + if (ns == &init_user_ns) + parent = init_securityfs_mount->mnt_root; + else + return ERR_PTR(-EINVAL); + } dir = d_inode(parent); @@ -168,7 +177,9 @@ static struct dentry *securityfs_create_dentry(const char *name, umode_t mode, dentry = ERR_PTR(error); out: inode_unlock(dir); - simple_release_fs(&mount, &mount_count); + if (ns == &init_user_ns) + simple_release_fs(&init_securityfs_mount, + &init_securityfs_mount_count); return dentry; } @@ -294,11 +305,14 @@ EXPORT_SYMBOL_GPL(securityfs_create_symlink); */ void securityfs_remove(struct dentry *dentry) { + struct user_namespace *ns; struct inode *dir; if (!dentry || IS_ERR(dentry)) return; + ns = dentry->d_sb->s_user_ns; + dir = d_inode(dentry->d_parent); inode_lock(dir); if (simple_positive(dentry)) { @@ -309,7 +323,9 @@ void securityfs_remove(struct dentry *dentry) dput(dentry); } inode_unlock(dir); - simple_release_fs(&mount, &mount_count); + if (ns == &init_user_ns) + simple_release_fs(&init_securityfs_mount, + &init_securityfs_mount_count); } EXPORT_SYMBOL_GPL(securityfs_remove);