[PATCH v3] tools/perf/util: null-terminate version char array upon error

From: Donald Yandt
Date: Tue May 14 2019 - 13:47:23 EST


If fgets fails due to any other error besides end-of-file, the version char array may not even be null-terminated.

Signed-off-by: Donald Yandt <donald.yandt@xxxxxxxxx>
Fixes: a1645ce12adb ("perf: 'perf kvm' tool for monitoring guest performance from host")
---
tools/perf/util/machine.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 3c520baa1..28a9541c4 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -1234,8 +1234,9 @@ static char *get_kernel_version(const char *root_dir)
if (!file)
return NULL;

- version[0] = '\0';
tmp = fgets(version, sizeof(version), file);
+ if (!tmp)
+ *version = '\0';
fclose(file);

name = strstr(version, prefix);
--
2.20.1