From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ian Rogers <irogers@google.com>
Cc: lv.yating@zte.com.cn, peterz@infradead.org, mingo@redhat.com,
namhyung@kernel.org, mark.rutland@arm.com,
alexander.shishkin@linux.intel.com, jolsa@kernel.org,
adrian.hunter@intel.com, james.clark@linaro.org,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
liu.qingtao2@zte.com.cn, he.yilin@zte.com.cn,
zhang.cheng35@zte.com.cn, ye.zhihao1@zte.com.cn,
shen.lin1@zte.com.cn, dai.hualiang@zte.com.cn,
stable@vger.kernel.org, hu.shengming@zte.com.cn
Subject: Re: [PATCH] perf machine: Fix NULL deref in thread__resolve_callchain_sample()
Date: Tue, 27 Oct 2026 17:37:29 -0300 [thread overview]
Message-ID: <auELiZHf3HldL5wQ@phoenix2> (raw)
In-Reply-To: <CAP-5=fUbpxz9HQV+BRd62Yk+mQ5Bq-G3XvcK8ea3W8E3BqM6jg@mail.gmail.com>
On Tue, Oct 27, 2026 at 08:21:16AM -0700, Ian Rogers wrote:
> On Tue, Oct 27, 2026 at 4:54 AM <lv.yating@zte.com.cn> wrote:
> > When recording with -j stack, resolve_lbr_callchain_sample() can
> > dereference a NULL 'chain' pointer while resolving the branch
> > stack.
> > $ perf record -j stack -e branches:u uname
> > perf: Segmentation fault
> > Fix it by checking 'chain' for NULL before dereferencing it.
> > Fixes: 29be60c93d2d ("perf build-id: Mark DSO in sample callchains")
> > Signed-off-by: lvyating <lv.yating@zte.com.cn>
> > Cc: stable@vger.kernel.org
> Tested-by: Ian Rogers <irogers@google.com>
> Reviewed-by: Ian Rogers <irogers@google.com>
Thanks, applied for v7.4.
> I wonder - this failure points to a lack of test coverage. For LBR the
> main coverage comes from:
> https://web.git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/tests/shell/record_lbr.sh?h=perf-tools-next
> Could you help expand the tests to avoid regressions?
That would be great indeed,
- Arnaldo
next prev parent reply other threads:[~2026-10-27 20:37 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-27 11:47 [PATCH] perf machine: Fix NULL deref in thread__resolve_callchain_sample() lv.yating
2026-10-27 12:11 ` sashiko-bot
2026-10-27 15:21 ` Ian Rogers
2026-10-27 20:37 ` Arnaldo Carvalho de Melo [this message]
[not found] <2026102719473296875zO7s1T904dguHCkN5vy@zte.com.cn>
2026-10-27 15:51 ` hu.shengming
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