From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 1/7] perf ordered_events: Fix crash in ordered_events__free Date: Mon, 21 Jan 2019 15:35:01 -0300 Message-ID: <20190121183507.23490-2-acme@kernel.org> References: <20190121183507.23490-1-acme@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190121183507.23490-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar Cc: Clark Williams , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Jiri Olsa , Song Liu , Alexander Shishkin , Namhyung Kim , Peter Zijlstra , Stephane Eranian , Arnaldo Carvalho de Melo List-Id: linux-perf-users.vger.kernel.org From: Jiri Olsa Song Liu reported crash in 'perf record': > #0 0x0000000000500055 in ordered_events(float, long double,...)(...) () > #1 0x0000000000500196 in ordered_events.reinit () > #2 0x00000000004fe413 in perf_session.process_events () > #3 0x0000000000440431 in cmd_record () > #4 0x00000000004a439f in run_builtin () > #5 0x000000000042b3e5 in main ()" This can happen when we get out of buffers during event processing. The subsequent ordered_events__free() call assumes oe->buffer != NULL and crashes. Add a check to prevent that. Reported-by: Song Liu Signed-off-by: Jiri Olsa Reviewed-by: Song Liu Tested-by: Song Liu Cc: Alexander Shishkin Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/20190117113017.12977-1-jolsa@kernel.org Fixes: d5ceb62b3654 ("perf ordered_events: Add 'struct ordered_events_buffer' layer") Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/ordered-events.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/ordered-events.c b/tools/perf/util/ordered-events.c index 897589507d97..ea523d3b248f 100644 --- a/tools/perf/util/ordered-events.c +++ b/tools/perf/util/ordered-events.c @@ -391,8 +391,10 @@ void ordered_events__free(struct ordered_events *oe) * Current buffer might not have all the events allocated * yet, we need to free only allocated ones ... */ - list_del(&oe->buffer->list); - ordered_events_buffer__free(oe->buffer, oe->buffer_idx, oe); + if (oe->buffer) { + list_del(&oe->buffer->list); + ordered_events_buffer__free(oe->buffer, oe->buffer_idx, oe); + } /* ... and continue with the rest */ list_for_each_entry_safe(buffer, tmp, &oe->to_free, list) { -- 2.20.1