diff options
| author | Masami Ichikawa <masami256@gmail.com> | 2020-01-16 22:12:36 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-01-29 16:45:25 +0100 |
| commit | 07af0d03e8b2e888b07ce5ed353fa8b6497918e1 (patch) | |
| tree | abf19901f281aa57373296acf1b83d5db00f58f7 /kernel | |
| parent | 67551f958458ba077c6237a14c4cf6a834cba667 (diff) | |
tracing: Do not set trace clock if tracefs lockdown is in effect
commit bf24daac8f2bd5b8affaec03c2be1d20bcdd6837 upstream.
When trace_clock option is not set and unstable clcok detected,
tracing_set_default_clock() sets trace_clock(ThinkPad A285 is one of
case). In that case, if lockdown is in effect, null pointer
dereference error happens in ring_buffer_set_clock().
Link: http://lkml.kernel.org/r/20200116131236.3866925-1-masami256@gmail.com
Cc: stable@vger.kernel.org
Fixes: 17911ff38aa58 ("tracing: Add locked_down checks to the open calls of files created for tracefs")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1788488
Signed-off-by: Masami Ichikawa <masami256@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bcb72f102613..341aab32c946 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9270,6 +9270,11 @@ __init static int tracing_set_default_clock(void) { /* sched_clock_stable() is determined in late_initcall */ if (!trace_boot_clock && !sched_clock_stable()) { + if (security_locked_down(LOCKDOWN_TRACEFS)) { + pr_warn("Can not set tracing clock due to lockdown\n"); + return -EPERM; + } + printk(KERN_WARNING "Unstable clock detected, switching default tracing clock to \"global\"\n" "If you want to keep using the local clock, then add:\n" |