| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 070/103] perf header: Fix divide by zero error if f_header.attr_size==0 | Date | Thu, 22 Aug 2019 10:18:58 -0700 |
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[ 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(+)
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 283148104ffbe..693dcd4ea6a38 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -2854,6 +2854,13 @@ 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", + 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
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