From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8BF6D46D2DC; Tue, 21 Jul 2026 18:07:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784657275; cv=none; b=cJVrWZwB/sr44hgX2Soy7DcLXW1DdVtQHn7Fw4ScPWnMiBGkDM7i3jUmxNWFJKl2BEs+FLp5noAdFBOx8o8t6WJFUX4oasjxDwGc7iKaDzDmMAo5nd34jqhoq/SjGdhKzAR/+PvxS64DLRcnbDib7giMYY1gjMgOo0eK4X8e+gE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784657275; c=relaxed/simple; bh=X0ngXoUD7lxLPa2/1aSulg9bRCgVaISXQ0Fd0NNaj4o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VRjICVo68nRbxfsKzlv+z1HjF10Qi8TVwvPZs5PicpOe1BopT2AQiyxayWaj5K0k+YjDO6fVH3BxoRxOOw7Pg4Ur3mdEF24f9kBpLr1rIxLanW90jzF1jmGaJGZJlhAhGM8XKpAaSgm79BcNf2uYLZcm7SgnS4KPBaIjyiPc030= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=B5fmnify; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="B5fmnify" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC9BE1F000E9; Tue, 21 Jul 2026 18:07:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784657274; bh=qZficGQ0Ox+CnRDM95/kZ/eINO+/jiBboxs6+HGTASk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=B5fmnifyAazMI7BYPM/jAMJ2mpEhJltv40z+CE5vYT6z+fJGiIs1wHr7BX89kwL/f /HwWAKw7aGD2vUr+RK6iKt0Ymfuux61dUCyjvM3Sej0cIJeA1YCS4lYMhxVJ9Y4Fz3 dvieAyKjLT8eZyZZOdl6DjxKKdF1FBOoRzZvxGX4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, sashiko-bot , Ingo Molnar , Namhyung Kim , Arnaldo Carvalho de Melo , Sasha Levin Subject: [PATCH 6.18 0649/1611] perf sched: Replace BUG_ON and add NULL checks in replay event helpers Date: Tue, 21 Jul 2026 17:12:45 +0200 Message-ID: <20260721152529.988226724@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152514.750365251@linuxfoundation.org> References: <20260721152514.750365251@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arnaldo Carvalho de Melo [ Upstream commit 75eafe4a3a93a0143a20c0cc286bfb9008ac1478 ] get_new_event() has three issues: 1. The zalloc() result is dereferenced without a NULL check, crashing on allocation failure. 2. BUG_ON(!task->atoms) kills the process when realloc() fails. Since perf.data is untrusted input, this should be a graceful error. 3. The realloc pattern assigns directly to task->atoms, losing the old pointer on failure. task->nr_events is also incremented before the realloc, leaving corrupted state on failure. Fix get_new_event() to: - Check the zalloc() result before dereferencing - Use a temporary for realloc() to avoid losing the old pointer - Increment nr_events only after successful realloc - Return NULL instead of calling BUG_ON on failure Also fix add_sched_event_wakeup() where zalloc() for wait_sem is passed to sem_init() without a NULL check. Update all callers (add_sched_event_run, add_sched_event_wakeup, add_sched_event_sleep) to handle NULL returns by returning early. The replay may produce incomplete output on OOM but will not crash. Fixes: ec156764d424 ("perf sched: Import schedbench.c") Reported-by: sashiko-bot Cc: Ingo Molnar Cc: Namhyung Kim Assisted-by: Claude:claude-opus-4.6 Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/builtin-sched.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index e93606446cc3c6..36c8a018a830f1 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -358,14 +358,25 @@ get_new_event(struct task_desc *task, u64 timestamp) struct sched_atom *event = zalloc(sizeof(*event)); unsigned long idx = task->nr_events; size_t size; + struct sched_atom **atoms_p; + + if (event == NULL) { + pr_err("ERROR: sched: failed to allocate event\n"); + return NULL; + } event->timestamp = timestamp; event->nr = idx; + size = sizeof(struct sched_atom *) * (task->nr_events + 1); + atoms_p = realloc(task->atoms, size); + if (!atoms_p) { + pr_err("ERROR: sched: failed to grow atoms array\n"); + free(event); + return NULL; + } + task->atoms = atoms_p; task->nr_events++; - size = sizeof(struct sched_atom *) * task->nr_events; - task->atoms = realloc(task->atoms, size); - BUG_ON(!task->atoms); task->atoms[idx] = event; @@ -396,6 +407,8 @@ static void add_sched_event_run(struct perf_sched *sched, struct task_desc *task } event = get_new_event(task, timestamp); + if (event == NULL) + return; event->type = SCHED_EVENT_RUN; event->duration = duration; @@ -409,6 +422,8 @@ static void add_sched_event_wakeup(struct perf_sched *sched, struct task_desc *t struct sched_atom *event, *wakee_event; event = get_new_event(task, timestamp); + if (event == NULL) + return; event->type = SCHED_EVENT_WAKEUP; event->wakee = wakee; @@ -423,6 +438,10 @@ static void add_sched_event_wakeup(struct perf_sched *sched, struct task_desc *t } wakee_event->wait_sem = zalloc(sizeof(*wakee_event->wait_sem)); + if (!wakee_event->wait_sem) { + pr_err("ERROR: sched: failed to allocate semaphore\n"); + return; + } sem_init(wakee_event->wait_sem, 0, 0); event->wait_sem = wakee_event->wait_sem; @@ -434,6 +453,9 @@ static void add_sched_event_sleep(struct perf_sched *sched, struct task_desc *ta { struct sched_atom *event = get_new_event(task, timestamp); + if (event == NULL) + return; + event->type = SCHED_EVENT_SLEEP; sched->nr_sleep_events++; -- 2.53.0