Files
linux-stable-mirror/include/linux/lsm_audit.h
T
Paul Moore 6af36aeb14 lsm: add backing_file LSM hooks
Stacked filesystems such as overlayfs do not currently provide the
necessary mechanisms for LSMs to properly enforce access controls on the
mmap() and mprotect() operations.  In order to resolve this gap, a LSM
security blob is being added to the backing_file struct and the following
new LSM hooks are being created:

 security_backing_file_alloc()
 security_backing_file_free()
 security_mmap_backing_file()

The first two hooks are to manage the lifecycle of the LSM security blob
in the backing_file struct, while the third provides a new mmap() access
control point for the underlying backing file.  It is also expected that
LSMs will likely want to update their security_file_mprotect() callback
to address issues with their mprotect() controls, but that does not
require a change to the security_file_mprotect() LSM hook.

There are a three other small changes to support these new LSM hooks:
* Pass the user file associated with a backing file down to
alloc_empty_backing_file() so it can be included in the
security_backing_file_alloc() hook.
* Add getter and setter functions for the backing_file struct LSM blob
as the backing_file struct remains private to fs/file_table.c.
* Constify the file struct field in the LSM common_audit_data struct to
better support LSMs that need to pass a const file struct pointer into
the common LSM audit code.

Thanks to Arnd Bergmann for identifying the missing EXPORT_SYMBOL_GPL()
and supplying a fixup.

Cc: stable@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-unionfs@vger.kernel.org
Cc: linux-erofs@lists.ozlabs.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2026-04-03 16:53:50 -04:00

154 lines
3.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Common LSM logging functions
* Heavily borrowed from selinux/avc.h
*
* Author : Etienne BASSET <etienne.basset@ensta.org>
*
* All credits to : Stephen Smalley
* All BUGS to : Etienne BASSET <etienne.basset@ensta.org>
*/
#ifndef _LSM_COMMON_LOGGING_
#define _LSM_COMMON_LOGGING_
#include <linux/stddef.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/kdev_t.h>
#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/audit.h>
#include <linux/in6.h>
#include <linux/path.h>
#include <linux/key.h>
#include <linux/skbuff.h>
#include <rdma/ib_verbs.h>
struct lsm_network_audit {
int netif;
const struct sock *sk;
u16 family;
__be16 dport;
__be16 sport;
union {
struct {
__be32 daddr;
__be32 saddr;
} v4;
struct {
struct in6_addr daddr;
struct in6_addr saddr;
} v6;
} fam;
};
struct lsm_ioctlop_audit {
struct path path;
u16 cmd;
};
struct lsm_ibpkey_audit {
u64 subnet_prefix;
u16 pkey;
};
struct lsm_ibendport_audit {
const char *dev_name;
u8 port;
};
/* Auxiliary data to use in generating the audit record. */
struct common_audit_data {
char type;
#define LSM_AUDIT_DATA_PATH 1
#define LSM_AUDIT_DATA_NET 2
#define LSM_AUDIT_DATA_CAP 3
#define LSM_AUDIT_DATA_IPC 4
#define LSM_AUDIT_DATA_TASK 5
#define LSM_AUDIT_DATA_KEY 6
#define LSM_AUDIT_DATA_NONE 7
#define LSM_AUDIT_DATA_KMOD 8
#define LSM_AUDIT_DATA_INODE 9
#define LSM_AUDIT_DATA_DENTRY 10
#define LSM_AUDIT_DATA_IOCTL_OP 11
#define LSM_AUDIT_DATA_FILE 12
#define LSM_AUDIT_DATA_IBPKEY 13
#define LSM_AUDIT_DATA_IBENDPORT 14
#define LSM_AUDIT_DATA_LOCKDOWN 15
#define LSM_AUDIT_DATA_NOTIFICATION 16
#define LSM_AUDIT_DATA_ANONINODE 17
#define LSM_AUDIT_DATA_NLMSGTYPE 18
union {
struct path path;
struct dentry *dentry;
struct inode *inode;
struct lsm_network_audit *net;
int cap;
int ipc_id;
struct task_struct *tsk;
#ifdef CONFIG_KEYS
struct {
key_serial_t key;
char *key_desc;
} key_struct;
#endif
char *kmod_name;
struct lsm_ioctlop_audit *op;
const struct file *file;
struct lsm_ibpkey_audit *ibpkey;
struct lsm_ibendport_audit *ibendport;
int reason;
const char *anonclass;
u16 nlmsg_type;
} u;
/* this union contains LSM specific data */
union {
#ifdef CONFIG_SECURITY_SMACK
struct smack_audit_data *smack_audit_data;
#endif
#ifdef CONFIG_SECURITY_SELINUX
struct selinux_audit_data *selinux_audit_data;
#endif
#ifdef CONFIG_SECURITY_APPARMOR
struct apparmor_audit_data *apparmor_audit_data;
#endif
}; /* per LSM data pointer union */
};
#define v4info fam.v4
#define v6info fam.v6
#ifdef CONFIG_AUDIT
int ipv4_skb_to_auditdata(struct sk_buff *skb,
struct common_audit_data *ad, u8 *proto);
#if IS_ENABLED(CONFIG_IPV6)
int ipv6_skb_to_auditdata(struct sk_buff *skb,
struct common_audit_data *ad, u8 *proto);
#endif /* IS_ENABLED(CONFIG_IPV6) */
void common_lsm_audit(struct common_audit_data *a,
void (*pre_audit)(struct audit_buffer *, void *),
void (*post_audit)(struct audit_buffer *, void *));
void audit_log_lsm_data(struct audit_buffer *ab,
const struct common_audit_data *a);
#else /* CONFIG_AUDIT */
static inline void common_lsm_audit(struct common_audit_data *a,
void (*pre_audit)(struct audit_buffer *, void *),
void (*post_audit)(struct audit_buffer *, void *))
{
}
static inline void audit_log_lsm_data(struct audit_buffer *ab,
const struct common_audit_data *a)
{
}
#endif /* CONFIG_AUDIT */
#endif