perf_counter: Require CAP_SYS_ADMIN for raw tracepoint data

Raw tracepoint data contains various kernel internals and
data from other users, so restrict this to CAP_SYS_ADMIN.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1249896452.17467.75.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 5229d16..b0b20a0 100644 (file)
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -3787,6 +3787,14 @@ static void tp_perf_counter_destroy(struct perf_counter *counter)
 
 static const struct pmu *tp_perf_counter_init(struct perf_counter *counter)
 {
+       /*
+        * Raw tracepoint data is a severe data leak, only allow root to
+        * have these.
+        */
+       if ((counter->attr.sample_type & PERF_SAMPLE_RAW) &&
+                       !capable(CAP_SYS_ADMIN))
+               return ERR_PTR(-EPERM);
+
        if (ftrace_profile_enable(counter->attr.config))
                return NULL;