[PATCH] perf: need CAP_SYS_ADMIN to create k/uprobe with perf_event_open()

[Song Liu]

Non-root user cannot create kprobe or uprobe through the text-based
interface (kprobe_events, uprobe_events). So they cannot create the
probes with perf_event_open(). To ensure this, we check
capable(CAP_SYS_ADMIN) at perf_[k,u]probe_event_init().

Fixes: e12f03d7031a ("perf/core: Implement the 'perf_kprobe' PMU")
Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")

Signed-off-by: Song Liu <songliubraving@xxxxxx>
Reported-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
---
 kernel/events/core.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index d7af828..2d5fe26 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8400,6 +8400,10 @@ static int perf_kprobe_event_init(struct perf_event =
*event)

        if (event->attr.type !=3D perf_kprobe.type)
                return -ENOENT;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EACCES;
+
        /*
         * no branch sampling for probe events
         */
@@ -8437,6 +8441,10 @@ static int perf_uprobe_event_init(struct perf_event =
*event)

        if (event->attr.type !=3D perf_uprobe.type)
                return -ENOENT;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EACCES;
+
        /*
         * no branch sampling for probe events
         */
--
2.9.5