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authorPeter Hurley <peter@hurleysoftware.com>2016-01-09 22:55:33 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-01-27 16:41:04 -0800
commit2e28d38ae1d9ced6ac2deb4001aca3f267304cdb (patch)
treec5d29fa6d7f7198d9500a7b78066c13b5cd77705 /kernel/audit.c
parent4d240b6442824df3b5e401459789bab5ee7777ae (diff)
downloadlinux-sh-2e28d38ae1d9ced6ac2deb4001aca3f267304cdb.tar.gz
tty: audit: Handle tty audit enable atomically
The audit_tty and audit_tty_log_passwd fields are actually bool values, so merge into single memory location to access atomically. NB: audit log operations may still occur after tty audit is disabled which is consistent with the existing functionality Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/audit.c')
-rw-r--r--kernel/audit.c25
1 files changed, 12 insertions, 13 deletions
diff --git a/kernel/audit.c b/kernel/audit.c
index 610f221df069..2651e423b2dc 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -1030,20 +1030,19 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
break;
case AUDIT_TTY_GET: {
struct audit_tty_status s;
- struct task_struct *tsk = current;
+ unsigned int t;
- spin_lock(&tsk->sighand->siglock);
- s.enabled = tsk->signal->audit_tty;
- s.log_passwd = tsk->signal->audit_tty_log_passwd;
- spin_unlock(&tsk->sighand->siglock);
+ t = READ_ONCE(current->signal->audit_tty);
+ s.enabled = t & AUDIT_TTY_ENABLE;
+ s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
break;
}
case AUDIT_TTY_SET: {
struct audit_tty_status s, old;
- struct task_struct *tsk = current;
struct audit_buffer *ab;
+ unsigned int t;
memset(&s, 0, sizeof(s));
/* guard against past and future API changes */
@@ -1053,14 +1052,14 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
(s.log_passwd != 0 && s.log_passwd != 1))
err = -EINVAL;
- spin_lock(&tsk->sighand->siglock);
- old.enabled = tsk->signal->audit_tty;
- old.log_passwd = tsk->signal->audit_tty_log_passwd;
- if (!err) {
- tsk->signal->audit_tty = s.enabled;
- tsk->signal->audit_tty_log_passwd = s.log_passwd;
+ if (err)
+ t = READ_ONCE(current->signal->audit_tty);
+ else {
+ t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
+ t = xchg(&current->signal->audit_tty, t);
}
- spin_unlock(&tsk->sighand->siglock);
+ old.enabled = t & AUDIT_TTY_ENABLE;
+ old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"