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

[ Upstream commit 7622236ceb ]

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>
This commit is contained in:
Vince Weaver 2019-07-23 11:06:01 -04:00 committed by Greg Kroah-Hartman
parent a5e40452c9
commit ab5aa579ca

View file

@ -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);