From 30ba5b0e66c872faa416a458d32cc3956ecb548a Mon Sep 17 00:00:00 2001 From: Donald Yandt <donald.yandt@gmail.com> Date: Tue, 14 May 2019 07:01:00 -0400 Subject: [PATCH] perf machine: Null-terminate version char array upon fgets(/proc/version) error 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@gmail.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Avi Kivity <avi@scylladb.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Yanmin Zhang <yanmin_zhang@linux.intel.com> Fixes: a1645ce12adb ("perf: 'perf kvm' tool for monitoring guest performance from host") Link: http://lkml.kernel.org/r/20190514110100.22019-1-donald.yandt@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- 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 3c520baa198cf..28a9541c48359 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); -- GitLab