From: Ian Rogers <irogers@google.com>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Numfor Mbiziwo-Tiapo <nums@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Namhyung Kim <namhyung@kernel.org>,
Song Liu <songliubraving@fb.com>,
mbd@fb.com, LKML <linux-kernel@vger.kernel.org>,
Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH v2] Fix annotate.c use of uninitialized value error
Date: Fri, 25 Oct 2019 15:11:02 -0700 [thread overview]
Message-ID: <CAP-5=fW8k6YWBYno2RWV5_mojn-0crvmPcLynKGBO_3WMCXfEA@mail.gmail.com> (raw)
In-Reply-To: <20190807113244.GA9605@krava>
It looks like this wasn't merged to tip. Does anything need addressing
to get it merged?
Thanks,
Ian
On Wed, Aug 7, 2019 at 4:32 AM Jiri Olsa <jolsa@redhat.com> wrote:
>
> On Mon, Jul 29, 2019 at 01:57:50PM -0700, Numfor Mbiziwo-Tiapo wrote:
> > Our local MSAN (Memory Sanitizer) build of perf throws a warning
> > that comes from the "dso__disassemble_filename" function in
> > "tools/perf/util/annotate.c" when running perf record.
> >
> > The warning stems from the call to readlink, in which "build_id_path"
> > was being read into "linkname". Since readlink does not null terminate,
> > an uninitialized memory access would later occur when "linkname" is
> > passed into the strstr function. This is simply fixed by null-terminating
> > "linkname" after the call to readlink.
> >
> > To reproduce this warning, build perf by running:
> > make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-fsanitize=memory\
> > -fsanitize-memory-track-origins"
> >
> > (Additionally, llvm might have to be installed and clang might have to
> > be specified as the compiler - export CC=/usr/bin/clang)
> >
> > then running:
> > tools/perf/perf record -o - ls / | tools/perf/perf --no-pager annotate\
> > -i - --stdio
> >
> > Please see the cover letter for why false positive warnings may be
> > generated.
> >
> > Signed-off-by: Numfor Mbiziwo-Tiapo <nums@google.com>
>
> Acked-by: Jiri Olsa <jolsa@kernel.org>
>
> thanks,
> jirka
>
> > ---
> > tools/perf/util/annotate.c | 15 +++++++++++----
> > 1 file changed, 11 insertions(+), 4 deletions(-)
> >
> > diff --git a/tools/perf/util/annotate.c b/tools/perf/util/annotate.c
> > index 70de8f6b3aee..e1b075b52dce 100644
> > --- a/tools/perf/util/annotate.c
> > +++ b/tools/perf/util/annotate.c
> > @@ -1627,6 +1627,7 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
> > char *build_id_filename;
> > char *build_id_path = NULL;
> > char *pos;
> > + int len;
> >
> > if (dso->symtab_type == DSO_BINARY_TYPE__KALLSYMS &&
> > !dso__is_kcore(dso))
> > @@ -1655,10 +1656,16 @@ static int dso__disassemble_filename(struct dso *dso, char *filename, size_t fil
> > if (pos && strlen(pos) < SBUILD_ID_SIZE - 2)
> > dirname(build_id_path);
> >
> > - if (dso__is_kcore(dso) ||
> > - readlink(build_id_path, linkname, sizeof(linkname)) < 0 ||
> > - strstr(linkname, DSO__NAME_KALLSYMS) ||
> > - access(filename, R_OK)) {
> > + if (dso__is_kcore(dso))
> > + goto fallback;
> > +
> > + len = readlink(build_id_path, linkname, sizeof(linkname) - 1);
> > + if (len < 0)
> > + goto fallback;
> > +
> > + linkname[len] = '\0';
> > + if (strstr(linkname, DSO__NAME_KALLSYMS) ||
> > + access(filename, R_OK)) {
> > fallback:
> > /*
> > * If we don't have build-ids or the build-id file isn't in the
> > --
> > 2.22.0.709.g102302147b-goog
> >
next prev parent reply other threads:[~2019-10-25 22:11 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-24 18:45 [PATCH 0/3] Perf UBsan Patches Numfor Mbiziwo-Tiapo
2019-07-24 18:45 ` [PATCH 1/3] Fix backward-ring-buffer.c format-truncation error Numfor Mbiziwo-Tiapo
2019-07-25 13:08 ` David Laight
2019-07-26 19:40 ` Arnaldo Carvalho de Melo
2019-07-29 20:57 ` [PATCH v2] Fix annotate.c use of uninitialized value error Numfor Mbiziwo-Tiapo
2019-08-07 11:32 ` Jiri Olsa
2019-10-25 22:11 ` Ian Rogers [this message]
2020-07-09 0:54 ` Ian Rogers
2020-07-09 15:38 ` Arnaldo Carvalho de Melo
2019-07-24 18:45 ` [PATCH 2/3] Fix ordered-events.c array-bounds error Numfor Mbiziwo-Tiapo
2019-07-26 19:33 ` Arnaldo Carvalho de Melo
2019-07-26 19:35 ` Arnaldo Carvalho de Melo
2019-07-24 18:45 ` [PATCH 3/3] Fix insn.c misaligned address error Numfor Mbiziwo-Tiapo
2019-07-25 13:06 ` David Laight
2019-07-25 21:18 ` Ian Rogers
2019-07-26 19:38 ` Arnaldo Carvalho de Melo
2019-07-27 9:46 ` Masami Hiramatsu
2019-07-29 8:22 ` Adrian Hunter
2019-07-29 19:32 ` Ian Rogers
2019-07-30 7:50 ` Adrian Hunter
2019-07-30 0:47 ` Masami Hiramatsu
2019-07-30 7:53 ` Adrian Hunter
2019-07-30 9:17 ` David Laight
2019-07-26 19:28 [PATCH 2/3] Fix annotate.c use of uninitialized value error Arnaldo Carvalho de Melo
2019-07-31 0:40 ` [PATCH v2] " Numfor Mbiziwo-Tiapo
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