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Commit db0a6fb5 authored by Richard Guy Briggs's avatar Richard Guy Briggs Committed by Paul Moore
Browse files

audit: add tty field to LOGIN event 



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().  Lock and bump the kref to protect it, adding
audit_put_tty() alias to decrement it.

Signed-off-by: default avatarRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: default avatarPaul Moore <paul@paul-moore.com>
parent 7ffb8e31

include/linux/audit.h

+24 −0
Original line number Diff line number Diff line
@@ -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 +344,23 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk) 
	return tsk->sessionid;

}



static inline struct tty_struct *audit_get_tty(struct task_struct *tsk)

{

	struct tty_struct *tty = NULL;

	unsigned long flags;



	spin_lock_irqsave(&tsk->sighand->siglock, flags);

	if (tsk->signal)

		tty = tty_kref_get(tsk->signal->tty);

	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);

	return tty;

}



static inline void audit_put_tty(struct tty_struct *tty)

{

	tty_kref_put(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 +518,12 @@ static inline unsigned int audit_get_sessionid(struct task_struct *tsk) 
{

	return -1;

}

static inline struct tty_struct *audit_get_tty(struct task_struct *tsk)

{

	return NULL;

}

static inline void audit_put_tty(struct tty_struct *tty)

{ }

static inline void audit_ipc_obj(struct kern_ipc_perm *ipcp)

{ }

static inline void audit_ipc_set_perm(unsigned long qbytes, uid_t uid,

kernel/audit.c

+5 −13
Original line number Diff line number Diff line
@@ -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>
@@ -1871,21 +1870,14 @@ 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;



	/* 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 = audit_get_tty(tsk);

	audit_log_format(ab,

			 " ppid=%d pid=%d auid=%u uid=%u gid=%u"

			 " euid=%u suid=%u fsuid=%u"
@@ -1901,11 +1893,11 @@ 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));



			 tty ? tty_name(tty) : "(none)",

			 audit_get_sessionid(tsk));

	audit_put_tty(tty);

	audit_log_format(ab, " comm=");

	audit_log_untrustedstring(ab, get_task_comm(comm, tsk));



	audit_log_d_path_exe(ab, tsk->mm);

	audit_log_task_context(ab);

}

kernel/auditsc.c

+6 −2
Original line number Diff line number Diff line
@@ -1980,6 +1980,7 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid, 
{

	struct audit_buffer *ab;

	uid_t uid, oldloginuid, loginuid;

	struct tty_struct *tty;



	if (!audit_enabled)

		return;
@@ -1987,14 +1988,17 @@ static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid, 
	uid = from_kuid(&init_user_ns, task_uid(current));

	oldloginuid = from_kuid(&init_user_ns, koldloginuid);

	loginuid = from_kuid(&init_user_ns, kloginuid),

	tty = audit_get_tty(current);



	ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);

	if (!ab)

		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, tty ? tty_name(tty) : "(none)",

			 oldsessionid, sessionid, !rc);

	audit_put_tty(tty);

	audit_log_end(ab);

}