[GIT PULL][PATCH] perf/ftrace: Fix paranoid level for enablingfunction tracer

From: Steven Rostedt
Date: Tue Nov 05 2013 - 16:24:17 EST


Please pull the latest ftrace/urgent tree, which can be found at:


Head SHA1: d1356abac98cce8e7765186f8093da1442d74d1d

Steven Rostedt (1):
perf/ftrace: Fix paranoid level for enabling function tracer

kernel/trace/trace_event_perf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
commit d1356abac98cce8e7765186f8093da1442d74d1d
Author: Steven Rostedt <rostedt@xxxxxxxxxxx>
Date: Tue Nov 5 12:51:11 2013 -0500

perf/ftrace: Fix paranoid level for enabling function tracer

The current default perf paranoid level is "1" which has
"perf_paranoid_kernel()" return false, and giving any operations that
use it, access to normal users. Unfortunately, this includes function
tracing and normal users should not be allowed to enable function
tracing by default.

The proper level is defined at "-1" (full perf access), which
"perf_paranoid_tracepoint_raw()" will only give access to. Use that
check instead for enabling function tracing.

Reported-by: Dave Jones <davej@xxxxxxxxxx>
Reported-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 3.4+
CVE: CVE-2013-2930
Fixes: ced39002f5ea ("ftrace, perf: Add support to use function tracepoint in perf")
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 80c36bc..78e27e3 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -26,7 +26,7 @@ static int perf_trace_event_perm(struct ftrace_event_call *tp_event,
/* The ftrace function trace is allowed only for root. */
if (ftrace_event_is_function(tp_event) &&
- perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN))
+ perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
return -EPERM;

/* No tracing, just counting, so no obvious leak */
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