From: Vince Weaver <[email protected]>

[ 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 <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1907231100440.14532@macbook-air
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
 tools/perf/util/header.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 7f2e3b1c746c9..94278f914cdca 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -3285,6 +3285,13 @@ int perf_session__read_header(struct perf_session 
*session)
                           data->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

Reply via email to