From nobody Tue Apr 28 23:19:02 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7BCDFC433F5 for ; Fri, 27 May 2022 08:27:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348889AbiE0I1s (ORCPT ); Fri, 27 May 2022 04:27:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234417AbiE0I1q (ORCPT ); Fri, 27 May 2022 04:27:46 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A112213E09 for ; Fri, 27 May 2022 01:27:44 -0700 (PDT) Received: from dggpemm500024.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4L8dFY3tkXzjX5S; Fri, 27 May 2022 16:26:57 +0800 (CST) Received: from dggpemm500006.china.huawei.com (7.185.36.236) by dggpemm500024.china.huawei.com (7.185.36.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 27 May 2022 16:27:38 +0800 Received: from mdc.huawei.com (10.175.112.208) by dggpemm500006.china.huawei.com (7.185.36.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 27 May 2022 16:27:37 +0800 From: Chen Jun To: , , , CC: Subject: [PATCH] arm64/smp: check !ipi_desc[i] in arch_show_interrupts Date: Fri, 27 May 2022 08:22:36 +0000 Message-ID: <20220527082236.78037-1-chenjun102@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.175.112.208] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500006.china.huawei.com (7.185.36.236) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" There is a potential dereferencing null pointer issue in arch_show_interrupts. Problem 1: int arch_show_interrupts(struct seq_file *p, int prec) for (i =3D 0; i < NR_IPI; i++) { seq_printf(p, "%10u ", irq_desc_kstat_cpu(ipi_desc[i], cpu)); Only ipi_desc[0..nr_ipi - 1] are initialized in set_smp_ipi_range. and ipi_desc[nr_ipi..NR_IPI] are NULL. irq_desc_kstat_cpu will dereference NULL pointer. For now, the problem can not be triggered, because NR_IPI is always equal to nr_ipi. Problem 2: If request_percpu_irq failed in set_smp_ipi_range, ipi_desc[i] would be NULL. irq_desc_kstat_cpu will dereference NULL pointer. check !ipi_desc[i] (as arm does) to avoid the problem. Signed-off-by: Chen Jun --- arch/arm64/kernel/smp.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 62ed361a4376..3d54f464428b 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -781,6 +781,9 @@ int arch_show_interrupts(struct seq_file *p, int prec) unsigned int cpu, i; =20 for (i =3D 0; i < NR_IPI; i++) { + if (!ipi_desc[i]) + continue; + seq_printf(p, "%*s%u:%s", prec - 1, "IPI", i, prec >=3D 4 ? " " : ""); for_each_online_cpu(cpu) --=20 2.17.1