This is a note to let you know that I've just added the patch titled

audit: add tty field to LOGIN event

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: audit-add-tty-field-to-login-event.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From db0a6fb5d97afe01fd9c47d37c6daa82d4d4001d Mon Sep 17 00:00:00 2001

From: Richard Guy Briggs rgb@redhat.com Date: Thu, 21 Apr 2016 14:14:01 -0400 Subject: audit: add tty field to LOGIN event

From: Richard Guy Briggs rgb@redhat.com

commit db0a6fb5d97afe01fd9c47d37c6daa82d4d4001d upstream.

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: Richard Guy Briggs rgb@redhat.com Signed-off-by: Paul Moore paul@paul-moore.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- include/linux/audit.h | 24 ++++++++++++++++++++++++ kernel/audit.c | 18 +++++------------- kernel/auditsc.c | 8 ++++++-- 3 files changed, 35 insertions(+), 15 deletions(-)

--- 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) @@ -239,6 +240,23 @@ static inline unsigned int audit_get_ses 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); @@ -410,6 +428,12 @@ static inline unsigned int audit_get_ses { 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, --- 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>

@@ -1876,21 +1875,14 @@ void audit_log_task_info(struct audit_bu { 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" @@ -1906,11 +1898,11 @@ void audit_log_task_info(struct audit_bu 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); } --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1976,6 +1976,7 @@ static void audit_log_set_loginuid(kuid_ { struct audit_buffer *ab; uid_t uid, oldloginuid, loginuid; + struct tty_struct *tty;

if (!audit_enabled) return; @@ -1983,14 +1984,17 @@ static void audit_log_set_loginuid(kuid_ 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); }

Patches currently in stable-queue which might be from rgb@redhat.com are

queue-4.4/audit-add-tty-field-to-login-event.patch