From: Roberto Sassu <roberto.sassu@huaweicloud.com>
To: viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz,
chuck.lever@oracle.com, jlayton@kernel.org, neilb@suse.de,
kolga@netapp.com, Dai.Ngo@oracle.com, tom@talpey.com,
paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com,
zohar@linux.ibm.com, dmitry.kasatkin@gmail.com,
eric.snowberg@oracle.com, dhowells@redhat.com, jarkko@kernel.org,
stephen.smalley.work@gmail.com, omosnace@redhat.com,
casey@schaufler-ca.com, shuah@kernel.org, mic@digikod.net
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-nfs@vger.kernel.org, linux-security-module@vger.kernel.org,
linux-integrity@vger.kernel.org, keyrings@vger.kernel.org,
selinux@vger.kernel.org, linux-kselftest@vger.kernel.org,
Roberto Sassu <roberto.sassu@huawei.com>,
Stefan Berger <stefanb@linux.ibm.com>
Subject: [PATCH v10 11/25] security: Introduce inode_post_removexattr hook
Date: Thu, 15 Feb 2024 11:30:59 +0100 [thread overview]
Message-ID: <20240215103113.2369171-12-roberto.sassu@huaweicloud.com> (raw)
In-Reply-To: <20240215103113.2369171-1-roberto.sassu@huaweicloud.com>
From: Roberto Sassu <roberto.sassu@huawei.com>
In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_removexattr hook.
At inode_removexattr hook, EVM verifies the file's existing HMAC value. At
inode_post_removexattr, EVM re-calculates the file's HMAC with the passed
xattr removed and other file metadata.
Other LSMs could similarly take some action after successful xattr removal.
The new hook cannot return an error and cannot cause the operation to be
reverted.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Christian Brauner <brauner@kernel.org>
---
fs/xattr.c | 9 +++++----
include/linux/lsm_hook_defs.h | 2 ++
include/linux/security.h | 5 +++++
security/security.c | 14 ++++++++++++++
4 files changed, 26 insertions(+), 4 deletions(-)
diff --git a/fs/xattr.c b/fs/xattr.c
index 09d927603433..f891c260a971 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -552,11 +552,12 @@ __vfs_removexattr_locked(struct mnt_idmap *idmap,
goto out;
error = __vfs_removexattr(idmap, dentry, name);
+ if (error)
+ return error;
- if (!error) {
- fsnotify_xattr(dentry);
- evm_inode_post_removexattr(dentry, name);
- }
+ fsnotify_xattr(dentry);
+ security_inode_post_removexattr(dentry, name);
+ evm_inode_post_removexattr(dentry, name);
out:
return error;
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index a0e9e48015a4..f849f7d5bb53 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -149,6 +149,8 @@ LSM_HOOK(int, 0, inode_getxattr, struct dentry *dentry, const char *name)
LSM_HOOK(int, 0, inode_listxattr, struct dentry *dentry)
LSM_HOOK(int, 0, inode_removexattr, struct mnt_idmap *idmap,
struct dentry *dentry, const char *name)
+LSM_HOOK(void, LSM_RET_VOID, inode_post_removexattr, struct dentry *dentry,
+ const char *name)
LSM_HOOK(int, 0, inode_set_acl, struct mnt_idmap *idmap,
struct dentry *dentry, const char *acl_name, struct posix_acl *kacl)
LSM_HOOK(int, 0, inode_get_acl, struct mnt_idmap *idmap,
diff --git a/include/linux/security.h b/include/linux/security.h
index 56c841aa3994..84ae03690340 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -380,6 +380,7 @@ int security_inode_getxattr(struct dentry *dentry, const char *name);
int security_inode_listxattr(struct dentry *dentry);
int security_inode_removexattr(struct mnt_idmap *idmap,
struct dentry *dentry, const char *name);
+void security_inode_post_removexattr(struct dentry *dentry, const char *name);
int security_inode_need_killpriv(struct dentry *dentry);
int security_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry);
int security_inode_getsecurity(struct mnt_idmap *idmap,
@@ -942,6 +943,10 @@ static inline int security_inode_removexattr(struct mnt_idmap *idmap,
return cap_inode_removexattr(idmap, dentry, name);
}
+static inline void security_inode_post_removexattr(struct dentry *dentry,
+ const char *name)
+{ }
+
static inline int security_inode_need_killpriv(struct dentry *dentry)
{
return cap_inode_need_killpriv(dentry);
diff --git a/security/security.c b/security/security.c
index 8b8a03291a8e..0f0f2c11ef73 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2453,6 +2453,20 @@ int security_inode_removexattr(struct mnt_idmap *idmap,
return evm_inode_removexattr(idmap, dentry, name);
}
+/**
+ * security_inode_post_removexattr() - Update the inode after a removexattr op
+ * @dentry: file
+ * @name: xattr name
+ *
+ * Update the inode after a successful removexattr operation.
+ */
+void security_inode_post_removexattr(struct dentry *dentry, const char *name)
+{
+ if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
+ return;
+ call_void_hook(inode_post_removexattr, dentry, name);
+}
+
/**
* security_inode_need_killpriv() - Check if security_inode_killpriv() required
* @dentry: associated dentry
--
2.34.1
next prev parent reply other threads:[~2024-02-15 10:35 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-15 10:30 [PATCH v10 00/25] security: Move IMA and EVM to the LSM infrastructure Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 01/25] ima: Align ima_inode_post_setattr() definition with " Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 02/25] ima: Align ima_file_mprotect() " Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 03/25] ima: Align ima_inode_setxattr() " Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 04/25] ima: Align ima_inode_removexattr() " Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 05/25] ima: Align ima_post_read_file() " Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 06/25] evm: Align evm_inode_post_setattr() " Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 07/25] evm: Align evm_inode_setxattr() " Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 08/25] evm: Align evm_inode_post_setxattr() " Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 09/25] security: Align inode_setattr hook definition with EVM Roberto Sassu
2024-02-15 10:30 ` [PATCH v10 10/25] security: Introduce inode_post_setattr hook Roberto Sassu
2024-02-15 10:30 ` Roberto Sassu [this message]
2024-02-15 10:31 ` [PATCH v10 12/25] security: Introduce file_post_open hook Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 13/25] security: Introduce file_release hook Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 14/25] security: Introduce path_post_mknod hook Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 15/25] security: Introduce inode_post_create_tmpfile hook Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 16/25] security: Introduce inode_post_set_acl hook Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 17/25] security: Introduce inode_post_remove_acl hook Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 18/25] security: Introduce key_post_create_or_update hook Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 19/25] integrity: Move integrity_kernel_module_request() to IMA Roberto Sassu
2024-02-15 16:09 ` Roberto Sassu
2024-02-16 0:25 ` Mimi Zohar
2024-02-15 10:31 ` [PATCH v10 20/25] ima: Move to LSM infrastructure Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 21/25] ima: Move IMA-Appraisal " Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 22/25] evm: Move " Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 23/25] evm: Make it independent from 'integrity' LSM Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 24/25] ima: " Roberto Sassu
2024-02-15 10:31 ` [PATCH v10 25/25] integrity: Remove LSM Roberto Sassu
2024-02-16 4:43 ` [PATCH v10 0/25] security: Move IMA and EVM to the LSM infrastructure Paul Moore
2024-02-16 7:54 ` Roberto Sassu
2024-02-16 22:34 ` [PATCH v10 00/25] " Eric Snowberg
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=20240215103113.2369171-12-roberto.sassu@huaweicloud.com \
--to=roberto.sassu@huaweicloud.com \
--cc=Dai.Ngo@oracle.com \
--cc=brauner@kernel.org \
--cc=casey@schaufler-ca.com \
--cc=chuck.lever@oracle.com \
--cc=dhowells@redhat.com \
--cc=dmitry.kasatkin@gmail.com \
--cc=eric.snowberg@oracle.com \
--cc=jack@suse.cz \
--cc=jarkko@kernel.org \
--cc=jlayton@kernel.org \
--cc=jmorris@namei.org \
--cc=keyrings@vger.kernel.org \
--cc=kolga@netapp.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=linux-nfs@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mic@digikod.net \
--cc=neilb@suse.de \
--cc=omosnace@redhat.com \
--cc=paul@paul-moore.com \
--cc=roberto.sassu@huawei.com \
--cc=selinux@vger.kernel.org \
--cc=serge@hallyn.com \
--cc=shuah@kernel.org \
--cc=stefanb@linux.ibm.com \
--cc=stephen.smalley.work@gmail.com \
--cc=tom@talpey.com \
--cc=viro@zeniv.linux.org.uk \
--cc=zohar@linux.ibm.com \
/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;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).