[tip:perf/core] perf util: Fix bad memory access in trace info.

[tip-bot for Chris Phlipot]

Commit-ID:  a72f64261359b7451f8478f2a2bf357b4e6c757f
Gitweb:     https://git.kernel.org/tip/a72f64261359b7451f8478f2a2bf357b4e6c757f
Author:     Chris Phlipot <cphlipot0@xxxxxxxxx>
AuthorDate: Tue, 28 Aug 2018 23:19:54 -0700
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Thu, 30 Aug 2018 14:50:50 -0300

perf util: Fix bad memory access in trace info.

In the write to the output_fd in the error condition of
record_saved_cmdline(), we are writing 8 bytes from a memory location on
the stack that contains a primitive that is only 4 bytes in size.
Change the primitive to 8 bytes in size to match the size of the write
in order to avoid reading unknown memory from the stack.

Signed-off-by: Chris Phlipot <cphlipot0@xxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20180829061954.18871-1-cphlipot0@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/util/trace-event-info.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/trace-event-info.c b/tools/perf/util/trace-event-info.c
index c85d0d1a65ed..7b0ca7cbb7de 100644
--- a/tools/perf/util/trace-event-info.c
+++ b/tools/perf/util/trace-event-info.c
@@ -377,7 +377,7 @@ out:
 
 static int record_saved_cmdline(void)
 {
-	unsigned int size;
+	unsigned long long size;
 	char *path;
 	struct stat st;
 	int ret, err = 0;