Re: [RFC PATCH ghak32 V2 03/13] audit: log container info of syscalls

[Steve Grubb]

On Fri, 16 Mar 2018 05:00:30 -0400
Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:

> Create a new audit record AUDIT_CONTAINER_INFO to document the
> container ID of a process if it is present.

As mentioned in a previous email, I think AUDIT_CONTAINER is more
suitable for the container record. One more comment below...

> Called from audit_log_exit(), syscalls are covered.
> 
> A sample raw event:
> type=SYSCALL msg=audit(1519924845.499:257): arch=c000003e syscall=257
> success=yes exit=3 a0=ffffff9c a1=56374e1cef30 a2=241 a3=1b6 items=2
> ppid=606 pid=635 auid=0 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0
> sgid=0 fsgid=0 tty=pts0 ses=3 comm="bash" exe="/usr/bin/bash"
> subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
> key="tmpcontainerid" type=CWD msg=audit(1519924845.499:257):
> cwd="/root" type=PATH msg=audit(1519924845.499:257): item=0
> name="/tmp/" inode=13863 dev=00:27 mode=041777 ouid=0 ogid=0
> rdev=00:00 obj=system_u:object_r:tmp_t:s0 nametype= PARENT
> cap_fp=0000000000000000 cap_fi=0000000000000000 cap_fe=0 cap_fver=0
> type=PATH msg=audit(1519924845.499:257): item=1
> name="/tmp/tmpcontainerid" inode=17729 dev=00:27 mode=0100644 ouid=0
> ogid=0 rdev=00:00 obj=unconfined_u:object_r:user_tmp_t:s0
> nametype=CREATE cap_fp=0000000000000000 cap_fi=0000000000000000
> cap_fe=0 cap_fver=0 type=PROCTITLE msg=audit(1519924845.499:257):
> proctitle=62617368002D6300736C65657020313B206563686F2074657374203E202F746D702F746D70636F6E7461696E65726964
> type=CONTAINER_INFO msg=audit(1519924845.499:257): op=task
> contid=123458
> 
> See: https://github.com/linux-audit/audit-kernel/issues/32
> Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> ---
>  include/linux/audit.h      |  5 +++++
>  include/uapi/linux/audit.h |  1 +
>  kernel/audit.c             | 20 ++++++++++++++++++++
>  kernel/auditsc.c           |  2 ++
>  4 files changed, 28 insertions(+)
> 
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index fe4ba3f..3acbe9d 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -154,6 +154,8 @@ extern void
> audit_log_link_denied(const char *operation, extern int
> audit_log_task_context(struct audit_buffer *ab); extern void
> audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk);
> +extern int audit_log_container_info(struct task_struct *tsk,
> +				     struct audit_context *context);
>  
>  extern int		    audit_update_lsm_rules(void);
>  
> @@ -205,6 +207,9 @@ static inline int audit_log_task_context(struct
> audit_buffer *ab) static inline void audit_log_task_info(struct
> audit_buffer *ab, struct task_struct *tsk)
>  { }
> +static inline int audit_log_container_info(struct task_struct *tsk,
> +					    struct audit_context
> *context); +{ }
>  #define audit_enabled 0
>  #endif /* CONFIG_AUDIT */
>  
> diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> index 921a71f..e83ccbd 100644
> --- a/include/uapi/linux/audit.h
> +++ b/include/uapi/linux/audit.h
> @@ -115,6 +115,7 @@
>  #define AUDIT_REPLACE		1329	/* Replace auditd
> if this packet unanswerd */ #define AUDIT_KERN_MODULE
> 1330	/* Kernel Module events */ #define
> AUDIT_FANOTIFY		1331	/* Fanotify access decision
> */ +#define AUDIT_CONTAINER_INFO	1332	/* Container ID
> information */ #define AUDIT_AVC		1400	/* SE
> Linux avc denial or grant */ #define AUDIT_SELINUX_ERR
> 1401	/* Internal SE Linux Errors */ diff --git
> a/kernel/audit.c b/kernel/audit.c index 3f2f143..a12f21f 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -2049,6 +2049,26 @@ void audit_log_session_info(struct
> audit_buffer *ab) audit_log_format(ab, " auid=%u ses=%u", auid,
> sessionid); }
>  
> +/*
> + * audit_log_container_info - report container info
> + * @tsk: task to be recorded
> + * @context: task or local context for record
> + */
> +int audit_log_container_info(struct task_struct *tsk, struct
> audit_context *context) +{
> +	struct audit_buffer *ab;
> +
> +	if (!audit_containerid_set(tsk))
> +		return 0;
> +	/* Generate AUDIT_CONTAINER_INFO with container ID */
> +	ab = audit_log_start(context, GFP_KERNEL,
> AUDIT_CONTAINER_INFO);
> +	if (!ab)
> +		return -ENOMEM;
> +	audit_log_format(ab, "contid=%llu",
> audit_get_containerid(tsk));
> +	audit_log_end(ab);
> +	return 0;
> +}
> +
>  void audit_log_key(struct audit_buffer *ab, char *key)
>  {
>  	audit_log_format(ab, " key=");
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index a6b0a52..65be110 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -1453,6 +1453,8 @@ static void audit_log_exit(struct audit_context
> *context, struct task_struct *ts 
>  	audit_log_proctitle(tsk, context);
>  
> +	audit_log_container_info(tsk, context);

Would there be any problem moving audit_log_container_info before
audit_log_proctitle? There are some assumptions that proctitle is the
last record in some situations.

Thanks,
-Steve

>  	/* Send end of event record to help user space know we are
> finished */ ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE);
>  	if (ab)