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[14/28] security: Introduce inode_post_setattr hook

Message ID 20230303181842.1087717-15-roberto.sassu@huaweicloud.com (mailing list archive)
State New, archived
Headers show
Series security: Move IMA and EVM to the LSM infrastructure | expand

Commit Message

Roberto Sassu March 3, 2023, 6:18 p.m. UTC 
From: Roberto Sassu <roberto.sassu@huawei.com>

In preparation for moving IMA and EVM to the LSM infrastructure, introduce
the inode_post_setattr hook.

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 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(+)

Comments

Stefan Berger March 6, 2023, 5:08 p.m. UTC | #1 
On 3/3/23 13:18, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
> 
> In preparation for moving IMA and EVM to the LSM infrastructure, introduce
> the inode_post_setattr hook.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Mimi Zohar March 8, 2023, 3:19 p.m. UTC | #2 
Hi Roberto,

On Fri, 2023-03-03 at 19:18 +0100, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
> 
> In preparation for moving IMA and EVM to the LSM infrastructure, introduce
> the inode_post_setattr hook.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>

Other than the one minor comment below,

Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
> ---
>  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 da45cf01be6..343d6d62435 100644
> --- a/fs/attr.c
> +++ b/fs/attr.c
> @@ -485,6 +485,7 @@ 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 4372a6b2632..eedefbcdde3 100644
> --- a/include/linux/lsm_hook_defs.h
> +++ b/include/linux/lsm_hook_defs.h
> @@ -135,6 +135,8 @@ 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 cd23221ce9e..64224216f6c 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -354,6 +354,8 @@ 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,
> @@ -855,6 +857,11 @@ 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 f7fe252e9d3..2dbf225f5d8 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -2190,6 +2190,22 @@ int security_inode_getattr(const struct path *path)
>  	return call_int_hook(inode_getattr, 0, path);
>  }
>  

Like the definitions, move the security_inode_post_setattr() to after
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 *entry,
> +				 int ia_valid)
> +{
> +	if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
> +		return;
> +	call_void_hook(inode_post_setattr, idmap, dentry, ia_valid);
> +}
> +
>  /**
>   * security_inode_setxattr() - Check if setting file xattrs is allowed
>   * @idmap: idmap of the mounth
diff mbox series

Patch

diff --git a/fs/attr.c b/fs/attr.c
index da45cf01be6..343d6d62435 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -485,6 +485,7 @@  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 4372a6b2632..eedefbcdde3 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -135,6 +135,8 @@  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 cd23221ce9e..64224216f6c 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -354,6 +354,8 @@  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,
@@ -855,6 +857,11 @@  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 f7fe252e9d3..2dbf225f5d8 100644
--- a/security/security.c
+++ b/security/security.c
@@ -2190,6 +2190,22 @@  int security_inode_getattr(const struct path *path)
 	return call_int_hook(inode_getattr, 0, path);
 }
 
+/**
+ * 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_setxattr() - Check if setting file xattrs is allowed
  * @idmap: idmap of the mount