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 10/25] security: Introduce inode_post_setattr hook
Date: Thu, 15 Feb 2024 11:30:58 +0100 [thread overview]
Message-ID: <20240215103113.2369171-11-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_setattr hook.
At inode_setattr hook, EVM verifies the file's existing HMAC value. At
inode_post_setattr, EVM re-calculates the file's HMAC based on the modified
file attributes and other file metadata.
Other LSMs could similarly take some action after successful file attribute
change.
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>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Acked-by: Christian Brauner <brauner@kernel.org>
---
fs/attr.c | 1 +
include/linux/lsm_hook_defs.h | 2 ++
include/linux/security.h | 7 +++++++
security/security.c | 16 ++++++++++++++++
4 files changed, 26 insertions(+)
diff --git a/fs/attr.c b/fs/attr.c
index adeba0ec40f1..990e1b3a3c91 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -502,6 +502,7 @@ int notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
if (!error) {
fsnotify_change(dentry, ia_valid);
+ security_inode_post_setattr(idmap, dentry, ia_valid);
ima_inode_post_setattr(idmap, dentry, ia_valid);
evm_inode_post_setattr(idmap, dentry, ia_valid);
}
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index b00b16d58413..a0e9e48015a4 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -137,6 +137,8 @@ LSM_HOOK(int, 0, inode_follow_link, struct dentry *dentry, struct inode *inode,
LSM_HOOK(int, 0, inode_permission, struct inode *inode, int mask)
LSM_HOOK(int, 0, inode_setattr, struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *attr)
+LSM_HOOK(void, LSM_RET_VOID, inode_post_setattr, struct mnt_idmap *idmap,
+ struct dentry *dentry, int ia_valid)
LSM_HOOK(int, 0, inode_getattr, const struct path *path)
LSM_HOOK(int, 0, inode_setxattr, struct mnt_idmap *idmap,
struct dentry *dentry, const char *name, const void *value,
diff --git a/include/linux/security.h b/include/linux/security.h
index d0eb20f90b26..56c841aa3994 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -361,6 +361,8 @@ int security_inode_follow_link(struct dentry *dentry, struct inode *inode,
int security_inode_permission(struct inode *inode, int mask);
int security_inode_setattr(struct mnt_idmap *idmap,
struct dentry *dentry, struct iattr *attr);
+void security_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+ int ia_valid);
int security_inode_getattr(const struct path *path);
int security_inode_setxattr(struct mnt_idmap *idmap,
struct dentry *dentry, const char *name,
@@ -879,6 +881,11 @@ static inline int security_inode_setattr(struct mnt_idmap *idmap,
return 0;
}
+static inline void
+security_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+ int ia_valid)
+{ }
+
static inline int security_inode_getattr(const struct path *path)
{
return 0;
diff --git a/security/security.c b/security/security.c
index 671472b34bbf..8b8a03291a8e 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2223,6 +2223,22 @@ int security_inode_setattr(struct mnt_idmap *idmap,
}
EXPORT_SYMBOL_GPL(security_inode_setattr);
+/**
+ * security_inode_post_setattr() - Update the inode after a setattr operation
+ * @idmap: idmap of the mount
+ * @dentry: file
+ * @ia_valid: file attributes set
+ *
+ * Update inode security field after successful setting file attributes.
+ */
+void security_inode_post_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+ int ia_valid)
+{
+ if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
+ return;
+ call_void_hook(inode_post_setattr, idmap, dentry, ia_valid);
+}
+
/**
* security_inode_getattr() - Check if getting file attributes is allowed
* @path: file
--
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 ` Roberto Sassu [this message]
2024-02-15 10:30 ` [PATCH v10 11/25] security: Introduce inode_post_removexattr hook Roberto Sassu
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
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