Re: [PATCH AUTOSEL 4.4 04/14] perf header: Fix divide by zero error if f_header.attr_size==0

Sasha Levin sashal@kernel.org 于2019年8月6日周二 下午11:39写道：

From: Vince Weaver vincent.weaver@maine.edu

[ Upstream commit 7622236ceb167aa3857395f9bdaf871442aa467e ]

So I have been having lots of trouble with hand-crafted perf.data files causing segfaults and the like, so I have started fuzzing the perf tool.

First issue found:

If f_header.attr_size is 0 in the perf.data file, then perf will crash with a divide-by-zero error.

Committer note:

Added a pr_err() to tell the user why the command failed.

Signed-off-by: Vince Weaver vincent.weaver@maine.edu Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Jiri Olsa jolsa@redhat.com Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1907231100440.14532@macbook-air Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org

---

tools/perf/util/header.c | 7 +++++++ 1 file changed, 7 insertions(+)

Hi all,

This on cause build failure when I rebased to 4.14.140-rc1 in stable-rc tree.

util/header.c: In function 'perf_session__read_header': util/header.c:2907:10: error: 'data' undeclared (first use in this function); did you mean 'dots'? data->file.path); Should be fixed by: --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2904,7 +2904,7 @@ int perf_session__read_header(struct perf_session *session) if (f_header.attr_size == 0) { pr_err("ERROR: The %s file's attr size field is 0 which is unexpected.\n" "Was the 'perf record' command properly terminated?\n", - data->file.path); + file->path); return -EINVAL;

Regards, Jack Wang

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 304f5d7101436..0102dd46fb6da 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2591,6 +2591,13 @@ int perf_session__read_header(struct perf_session *session) file->path); }

•   if (f_header.attr_size == 0) {
  

•           pr_err("ERROR: The %s file's attr size field is 0 which is unexpected.\n"
  

•                  "Was the 'perf record' command properly terminated?\n",
  

•                  data->file.path);
  

•           return -EINVAL;
  

•   }
  

•   nr_attrs = f_header.attrs.size / f_header.attr_size;
    lseek(fd, f_header.attrs.offset, SEEK_SET);
  
  

-- 2.20.1