Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1378337 > unrolled thread

[PATCH] audit: add tty field to LOGIN event

Started byRichard Guy Briggs <rgb@redhat.com>
First post2016-04-14 01:30 +0200
Last post2016-04-14 02:40 +0200
Articles 2 — 2 participants

Back to article view | Back to linux.kernel


Contents

  [PATCH] audit: add tty field to LOGIN event Richard Guy Briggs <rgb@redhat.com> - 2016-04-14 01:30 +0200
    Re: [PATCH] audit: add tty field to LOGIN event Peter Hurley <peter@hurleysoftware.com> - 2016-04-14 02:40 +0200

#1378337 — [PATCH] audit: add tty field to LOGIN event

FromRichard Guy Briggs <rgb@redhat.com>
Date2016-04-14 01:30 +0200
Subject[PATCH] audit: add tty field to LOGIN event
Message-ID<rnCoq-IX-11@gated-at.bofh.it>
The tty field was missing from AUDIT_LOGIN events.

Refactor code to create a new function audit_get_tty(), using it to
replace the call in audit_log_task_info() and to add it to
audit_log_set_loginuid().

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
---
 include/linux/audit.h |   18 ++++++++++++++++++
 kernel/audit.c        |   11 +----------
 kernel/auditsc.c      |    5 +++--
 3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h
index b40ed5d..20c6649 100644
--- a/include/linux/audit.h
+++ b/include/linux/audit.h
@@ -26,6 +26,7 @@
 #include <linux/sched.h>
 #include <linux/ptrace.h>
 #include <uapi/linux/audit.h>
+#include <linux/tty.h>
 
 #define AUDIT_INO_UNSET ((unsigned long)-1)
 #define AUDIT_DEV_UNSET ((dev_t)-1)
@@ -343,6 +344,19 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
 	return tsk->sessionid;
 }
 
+static inline char *audit_get_tty(struct task_struct *tsk)
+{
+	char *tty;
+
+	spin_lock_irq(&tsk->sighand->siglock);
+	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
+		tty = tsk->signal->tty->name;
+	else
+		tty = "(none)";
+	spin_unlock_irq(&tsk->sighand->siglock);
+	return tty;
+}
+
 extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
 extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
 extern void __audit_bprm(struct linux_binprm *bprm);
@@ -500,6 +514,10 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
 {
 	return -1;
 }
+static inline char *audit_get_tty(struct task_struct *tsk)
+{
+	return "(invalid)";
+}
 static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
 { }
 static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid,
diff --git a/kernel/audit.c b/kernel/audit.c
index 3a3e5de..fae11df 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -64,7 +64,6 @@
 #include <linux/security.h>
 #endif
 #include <linux/freezer.h>
-#include <linux/tty.h>
 #include <linux/pid_namespace.h>
 #include <net/netns/generic.h>
 
@@ -1873,7 +1872,6 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 {
 	const struct cred *cred;
 	char comm[sizeof(tsk->comm)];
-	char *tty;
 
 	if (!ab)
 		return;
@@ -1881,13 +1879,6 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 	/* tsk == current */
 	cred = current_cred();
 
-	spin_lock_irq(&tsk->sighand->siglock);
-	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
-		tty = tsk->signal->tty->name;
-	else
-		tty = "(none)";
-	spin_unlock_irq(&tsk->sighand->siglock);
-
 	audit_log_format(ab,
 			 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
 			 " euid=%u suid=%u fsuid=%u"
@@ -1903,7 +1894,7 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
 			 from_kgid(&init_user_ns, cred->egid),
 			 from_kgid(&init_user_ns, cred->sgid),
 			 from_kgid(&init_user_ns, cred->fsgid),
-			 tty, audit_get_sessionid(tsk));
+			 audit_get_tty(tsk), audit_get_sessionid(tsk));
 
 	audit_log_format(ab, " comm=");
 	audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 195ffae..a0467fb 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1993,8 +1993,9 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
 		return;
 	audit_log_format(ab, "pid=%d uid=%u", task_pid_nr(current), uid);
 	audit_log_task_context(ab);
-	audit_log_format(ab, " old-auid=%u auid=%u old-ses=%u ses=%u res=%d",
-			 oldloginuid, loginuid, oldsessionid, sessionid, !rc);
+	audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
+			 oldloginuid, loginuid, audit_get_tty(current),
+			 oldsessionid, sessionid, !rc);
 	audit_log_end(ab);
 }
 
-- 
1.7.1

[toc] | [next] | [standalone]


#1378368

FromPeter Hurley <peter@hurleysoftware.com>
Date2016-04-14 02:40 +0200
Message-ID<rnDu9-1rq-7@gated-at.bofh.it>
In reply to#1378337
Hi Richard,

On 04/13/2016 04:25 PM, Richard Guy Briggs wrote:
> The tty field was missing from AUDIT_LOGIN events.
> 
> Refactor code to create a new function audit_get_tty(), using it to
> replace the call in audit_log_task_info() and to add it to
> audit_log_set_loginuid().
> 
> Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
> ---
>  include/linux/audit.h |   18 ++++++++++++++++++
>  kernel/audit.c        |   11 +----------
>  kernel/auditsc.c      |    5 +++--
>  3 files changed, 22 insertions(+), 12 deletions(-)
> 
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index b40ed5d..20c6649 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -26,6 +26,7 @@
>  #include <linux/sched.h>
>  #include <linux/ptrace.h>
>  #include <uapi/linux/audit.h>
> +#include <linux/tty.h>
>  
>  #define AUDIT_INO_UNSET ((unsigned long)-1)
>  #define AUDIT_DEV_UNSET ((dev_t)-1)
> @@ -343,6 +344,19 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
>  	return tsk->sessionid;
>  }
>  
> +static inline char *audit_get_tty(struct task_struct *tsk)
> +{
> +	char *tty;
> +
> +	spin_lock_irq(&tsk->sighand->siglock);
> +	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
> +		tty = tsk->signal->tty->name;
> +	else
> +		tty = "(none)";
> +	spin_unlock_irq(&tsk->sighand->siglock);

This is unsafe because the tty could be immediately torn down after the
siglock is dropped, and return a dangling ptr.


> +	return tty;
> +}
> +
>  extern void __audit_ipc_obj(struct kern_ipc_perm *ipcp);
>  extern void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode);
>  extern void __audit_bprm(struct linux_binprm *bprm);
> @@ -500,6 +514,10 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk)
>  {
>  	return -1;
>  }
> +static inline char *audit_get_tty(struct task_struct *tsk)
> +{
> +	return "(invalid)";
> +}
>  static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)
>  { }
>  static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid,
> diff --git a/kernel/audit.c b/kernel/audit.c
> index 3a3e5de..fae11df 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -64,7 +64,6 @@
>  #include <linux/security.h>
>  #endif
>  #include <linux/freezer.h>
> -#include <linux/tty.h>
>  #include <linux/pid_namespace.h>
>  #include <net/netns/generic.h>
>  
> @@ -1873,7 +1872,6 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
>  {
>  	const struct cred *cred;
>  	char comm[sizeof(tsk->comm)];
> -	char *tty;

	struct tty_struct *tty;

>  
>  	if (!ab)
>  		return;
> @@ -1881,13 +1879,6 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
>  	/* tsk == current */
>  	cred = current_cred();
>  
> -	spin_lock_irq(&tsk->sighand->siglock);
> -	if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
> -		tty = tsk->signal->tty->name;
> -	else
> -		tty = "(none)";
> -	spin_unlock_irq(&tsk->sighand->siglock);

	tty = get_current_tty();
	
> -
>  	audit_log_format(ab,
>  			 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
>  			 " euid=%u suid=%u fsuid=%u"
> @@ -1903,7 +1894,7 @@ void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
>  			 from_kgid(&init_user_ns, cred->egid),
>  			 from_kgid(&init_user_ns, cred->sgid),
>  			 from_kgid(&init_user_ns, cred->fsgid),
> -			 tty, audit_get_sessionid(tsk));
> +			 audit_get_tty(tsk), audit_get_sessionid(tsk));

			tty_name(tty), ....);
			^^^^^^^^^^
			returns "NULL tty" if tty == NULL

	tty_kref_put(tty);


>  
>  	audit_log_format(ab, " comm=");
>  	audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 195ffae..a0467fb 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -1993,8 +1993,9 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
>  		return;
>  	audit_log_format(ab, "pid=%d uid=%u", task_pid_nr(current), uid);
>  	audit_log_task_context(ab);
> -	audit_log_format(ab, " old-auid=%u auid=%u old-ses=%u ses=%u res=%d",
> -			 oldloginuid, loginuid, oldsessionid, sessionid, !rc);

	tty = get_current_tty();

> +	audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
> +			 oldloginuid, loginuid, audit_get_tty(current),

			......., tty_name(tty),

> +			 oldsessionid, sessionid, !rc);

	tty_kref_put(tty);

Regards,
Peter Hurley


>  	audit_log_end(ab);
>  }
>  
> 

[toc] | [prev] | [standalone]


Back to top | Article view | linux.kernel


csiph-web