Unverified Commit defdd02d authored by Andrey Albershteyn's avatar Andrey Albershteyn Committed by Christian Brauner
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lsm: introduce new hooks for setting/getting inode fsxattr 



Introduce new hooks for setting and getting filesystem extended
attributes on inode (FS_IOC_FSGETXATTR).

Cc: selinux@vger.kernel.org
Cc: Paul Moore <paul@paul-moore.com>

Acked-by: default avatarPaul Moore <paul@paul-moore.com>
Signed-off-by: default avatarAndrey Albershteyn <aalbersh@kernel.org>
Link: https://lore.kernel.org/20250630-xattrat-syscall-v6-2-c4e3bc35227b@kernel.org


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 2f952c9e

fs/file_attr.c

+16 −3
Original line number Diff line number Diff line
@@ -77,10 +77,15 @@ EXPORT_SYMBOL(fileattr_fill_flags); 
int vfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)

{

	struct inode *inode = d_inode(dentry);

	int error;



	if (!inode->i_op->fileattr_get)

		return -ENOIOCTLCMD;



	error = security_inode_file_getattr(dentry, fa);

	if (error)

		return error;



	return inode->i_op->fileattr_get(dentry, fa);

}

EXPORT_SYMBOL(vfs_fileattr_get);
@@ -243,12 +248,20 @@ int vfs_fileattr_set(struct mnt_idmap *idmap, struct dentry *dentry, 
		} else {

			fa->flags |= old_ma.flags & ~FS_COMMON_FL;

		}



		err = fileattr_set_prepare(inode, &old_ma, fa);

		if (!err)

		if (err)

			goto out;

		err = security_inode_file_setattr(dentry, fa);

		if (err)

			goto out;

		err = inode->i_op->fileattr_set(idmap, dentry, fa);

		if (err)

			goto out;

	}

	inode_unlock(inode);



out:

	inode_unlock(inode);

	return err;

}

EXPORT_SYMBOL(vfs_fileattr_set);

include/linux/lsm_hook_defs.h

+2 −0
Original line number Diff line number Diff line
@@ -157,6 +157,8 @@ 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_file_setattr, struct dentry *dentry, struct fileattr *fa)

LSM_HOOK(int, 0, inode_file_getattr, struct dentry *dentry, struct fileattr *fa)

LSM_HOOK(int, 0, inode_set_acl, struct mnt_idmap *idmap,

	 struct dentry *dentry, const char *acl_name, struct posix_acl *kacl)

LSM_HOOK(void, LSM_RET_VOID, inode_post_set_acl, struct dentry *dentry,

include/linux/security.h

+16 −0
Original line number Diff line number Diff line
@@ -451,6 +451,10 @@ 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_file_setattr(struct dentry *dentry,

			      struct fileattr *fa);

int security_inode_file_getattr(struct dentry *dentry,

			      struct fileattr *fa);

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,
@@ -1052,6 +1056,18 @@ static inline void security_inode_post_removexattr(struct dentry *dentry, 
						   const char *name)

{ }



static inline int security_inode_file_setattr(struct dentry *dentry,

					      struct fileattr *fa)

{

	return 0;

}



static inline int security_inode_file_getattr(struct dentry *dentry,

					      struct fileattr *fa)

{

	return 0;

}



static inline int security_inode_need_killpriv(struct dentry *dentry)

{

	return cap_inode_need_killpriv(dentry);

security/security.c

+30 −0
Original line number Diff line number Diff line
@@ -2622,6 +2622,36 @@ void security_inode_post_removexattr(struct dentry *dentry, const char *name) 
	call_void_hook(inode_post_removexattr, dentry, name);

}



/**

 * security_inode_file_setattr() - check if setting fsxattr is allowed

 * @dentry: file to set filesystem extended attributes on

 * @fa: extended attributes to set on the inode

 *

 * Called when file_setattr() syscall or FS_IOC_FSSETXATTR ioctl() is called on

 * inode

 *

 * Return: Returns 0 if permission is granted.

 */

int security_inode_file_setattr(struct dentry *dentry, struct fileattr *fa)

{

	return call_int_hook(inode_file_setattr, dentry, fa);

}



/**

 * security_inode_file_getattr() - check if retrieving fsxattr is allowed

 * @dentry: file to retrieve filesystem extended attributes from

 * @fa: extended attributes to get

 *

 * Called when file_getattr() syscall or FS_IOC_FSGETXATTR ioctl() is called on

 * inode

 *

 * Return: Returns 0 if permission is granted.

 */

int security_inode_file_getattr(struct dentry *dentry, struct fileattr *fa)

{

	return call_int_hook(inode_file_getattr, dentry, fa);

}



/**

 * security_inode_need_killpriv() - Check if security_inode_killpriv() required

 * @dentry: associated dentry