Commit 7622236c authored Jul 23, 2019 by Vince Weaver Committed by Arnaldo Carvalho de Melo Jul 29, 2019

perf header: Fix divide by zero error if f_header.attr_size==0



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>

parent e54599c9

tools/perf/util/header.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -3559,6 +3559,13 @@ 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);

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