Re: [PATCH ghak81 RFC V1 2/5] audit: convert sessionid unset to a macro

From: Richard Guy Briggs
Date: Tue May 08 2018 - 21:34:41 EST


On 2018-05-04 16:54, Richard Guy Briggs wrote:
> Use a macro, "AUDIT_SID_UNSET", to replace each instance of
> initialization and comparison to an audit session ID.
>
> Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>

There's a minor issue with this patch, adding a header include to
init/init_task.c in this patch and removing it from patch 5. That'll be
in the next revision.

I have dynamic allocation working, so that has a good chance of
appearing too.

> ---
> include/linux/audit.h | 2 +-
> include/net/xfrm.h | 2 +-
> include/uapi/linux/audit.h | 1 +
> init/init_task.c | 2 +-
> kernel/auditsc.c | 4 ++--
> 5 files changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index 75d5b03..5f86f7c 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -513,7 +513,7 @@ static inline kuid_t audit_get_loginuid(struct task_struct *tsk)
> }
> static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
> {
> - return -1;
> + return AUDIT_SID_UNSET;
> }
> static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
> { }
> diff --git a/include/net/xfrm.h b/include/net/xfrm.h
> index a872379..fcce8ee 100644
> --- a/include/net/xfrm.h
> +++ b/include/net/xfrm.h
> @@ -751,7 +751,7 @@ static inline void xfrm_audit_helper_usrinfo(bool task_valid,
> audit_get_loginuid(current) :
> INVALID_UID);
> const unsigned int ses = task_valid ? audit_get_sessionid(current) :
> - (unsigned int) -1;
> + AUDIT_SID_UNSET;
>
> audit_log_format(audit_buf, " auid=%u ses=%u", auid, ses);
> audit_log_task_context(audit_buf);
> diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
> index 4e61a9e..04f9bd2 100644
> --- a/include/uapi/linux/audit.h
> +++ b/include/uapi/linux/audit.h
> @@ -465,6 +465,7 @@ struct audit_tty_status {
> };
>
> #define AUDIT_UID_UNSET (unsigned int)-1
> +#define AUDIT_SID_UNSET ((unsigned int)-1)
>
> /* audit_rule_data supports filter rules with both integer and string
> * fields. It corresponds with AUDIT_ADD_RULE, AUDIT_DEL_RULE and
> diff --git a/init/init_task.c b/init/init_task.c
> index 3ac6e75..c788f91 100644
> --- a/init/init_task.c
> +++ b/init/init_task.c
> @@ -119,7 +119,7 @@ struct task_struct init_task
> .thread_node = LIST_HEAD_INIT(init_signals.thread_head),
> #ifdef CONFIG_AUDITSYSCALL
> .loginuid = INVALID_UID,
> - .sessionid = (unsigned int)-1,
> + .sessionid = AUDIT_SID_UNSET,
> #endif
> #ifdef CONFIG_PERF_EVENTS
> .perf_event_mutex = __MUTEX_INITIALIZER(init_task.perf_event_mutex),
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index f3817d0..6e3ceb9 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -2050,7 +2050,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
> int audit_set_loginuid(kuid_t loginuid)
> {
> struct task_struct *task = current;
> - unsigned int oldsessionid, sessionid = (unsigned int)-1;
> + unsigned int oldsessionid, sessionid = AUDIT_SID_UNSET;
> kuid_t oldloginuid;
> int rc;
>
> @@ -2064,7 +2064,7 @@ int audit_set_loginuid(kuid_t loginuid)
> /* are we setting or clearing? */
> if (uid_valid(loginuid)) {
> sessionid = (unsigned int)atomic_inc_return(&session_id);
> - if (unlikely(sessionid == (unsigned int)-1))
> + if (unlikely(sessionid == AUDIT_SID_UNSET))
> sessionid = (unsigned int)atomic_inc_return(&session_id);
> }
>
> --
> 1.8.3.1
>
> --
> Linux-audit mailing list
> Linux-audit@xxxxxxxxxx
> https://www.redhat.com/mailman/listinfo/linux-audit

- RGB

--
Richard Guy Briggs <rgb@xxxxxxxxxx>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635