[PATCH 4.9 19/88] sysrq: Restore original console_loglevel when sysrq disabled

From: Greg Kroah-Hartman
Date: Tue Mar 10 2020 - 08:44:38 EST


From: Petr Mladek <pmladek@xxxxxxxx>

commit 075e1a0c50f59ea210561d0d0fedbd945615df78 upstream.

The sysrq header line is printed with an increased loglevel
to provide users some positive feedback.

The original loglevel is not restored when the sysrq operation
is disabled. This bug was introduced in 2.6.12 (pre-git-history)
by the commit ("Allow admin to enable only some of the Magic-Sysrq
functions").

Signed-off-by: Petr Mladek <pmladek@xxxxxxxx>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
Reviewed-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Cc: Tommi Rantala <tommi.t.rantala@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/tty/sysrq.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -557,6 +557,7 @@ void __handle_sysrq(int key, bool check_
op_p->handler(key);
} else {
pr_cont("This sysrq operation is disabled.\n");
+ console_loglevel = orig_log_level;
}
} else {
pr_cont("HELP : ");