UPSTREAM: perf: Treat attr.config as u64 in perf_swevent_init()

Trinity discovered that we fail to check all 64 bits of
attr.config passed by user space, resulting to out-of-bounds
access of the perf_swevent_enabled array in
sw_perf_event_destroy().

Introduced in commit b0a873ebb ("perf: Register PMU
implementations").

Signed-off-by: Tommi Rantala <tt.rantala@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: davej@redhat.com
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/1365882554-30259-1-git-send-email-tt.rantala@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
BUG=chromium:240706
TEST=link build, exploit fails

Change-Id: I69496233eb3f1b8c5411685a5c546255c6e6be38
Signed-off-by: Kees Cook <keescook@chromium.org>
[upstream commit 8176cced706b5e5d15887584150764894e94e02f]
Reviewed-on: https://gerrit.chromium.org/gerrit/51134
Reviewed-by: Julien Tinnes <jln@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>

diff --git a/kernel/events/core.c b/kernel/events/core.c
index fd126f8..aafa4c1 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5118,7 +5118,7 @@ static void sw_perf_event_destroy(struct perf_event *event)
 
 static int perf_swevent_init(struct perf_event *event)
 {
-       int event_id = event->attr.config;
+       u64 event_id = event->attr.config;
 
        if (event->attr.type != PERF_TYPE_SOFTWARE)
                return -ENOENT;