From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) (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 72C3313C9C4; Thu, 28 Aug 2025 13:04:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.132 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756386249; cv=none; b=jqzrhFlpmIaKBAxZv36qSUfGimclMPl+ozKBCPu1QN+VjS3T1zwArseqXycYMXFFmhkJzseJGtpE0q7LWzeqSw2dWkJjQTn5leWi0pYwDScdMN2BZIwXwggQkj+//onuF+xzmrWQNVtsk6pUt9fd09nu4YYqc7gcybyIYEu8Hhk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756386249; c=relaxed/simple; bh=87R04Ox+ehTuM5qn/vfSbAZfNCAWzfGxR1PC7L0e8jI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=fuOa9beAwOOgOxHA9aelSq/a8Go9wQ/FXSspzBNH0UT4jj2ZBIPQiODensJcT3hrPlMR2UQJjSG3OsUmlhIDreBT0QbEsWBLgrOyBnFXj2iVgSt6J+tsI8y/xGK/NpOzO/ubamJIIo6+P+xpApQFcC6b0jmZkmQRc04W0iwCB0E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=NdiOrjfM; arc=none smtp.client-ip=115.124.30.132 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="NdiOrjfM" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1756386242; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=C1ejW/71ETj9A3bcLkx0oDuGH2F9c7HT+2BpATISzr4=; b=NdiOrjfM5LMPhTXFvYPUnTmA/DYXZa9J3oojkvB86LBeEFeD/Doqi8o+2PIjuyaz8+8+7PnjQBt3opFq/hG4OVD9MqSJ27rZYspItI6CqGK4bYf4ze7fNEC2mYbIN9h8fMw7H+GBWblboBn8SEPB+jOWIVkgHLo8ESSRHx7e58I= Received: from 30.221.116.45(mailfrom:guangguan.wang@linux.alibaba.com fp:SMTPD_---0WmnCu3f_1756386240 cluster:ay36) by smtp.aliyun-inc.com; Thu, 28 Aug 2025 21:04:01 +0800 Message-ID: Date: Thu, 28 Aug 2025 21:04:00 +0800 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync() To: Liu Jian , alibuda@linux.alibaba.com, dust.li@linux.alibaba.com, sidraya@linux.ibm.com, wenjia@linux.ibm.com, mjambigi@linux.ibm.com, tonylu@linux.alibaba.com, guwen@linux.alibaba.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org Cc: linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org References: <20250828124117.2622624-1-liujian56@huawei.com> From: Guangguan Wang In-Reply-To: <20250828124117.2622624-1-liujian56@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 在 2025/8/28 20:41, Liu Jian 写道: > BUG: kernel NULL pointer dereference, address: 00000000000002ec > PGD 0 P4D 0 > Oops: Oops: 0000 [#1] SMP PTI > CPU: 28 UID: 0 PID: 343 Comm: kworker/28:1 Kdump: loaded Tainted: G OE 6.17.0-rc2+ #9 NONE > Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 > Workqueue: smc_hs_wq smc_listen_work [smc] > RIP: 0010:smc_ib_is_sg_need_sync+0x9e/0xd0 [smc] > ... > Call Trace: > > smcr_buf_map_link+0x211/0x2a0 [smc] > __smc_buf_create+0x522/0x970 [smc] > smc_buf_create+0x3a/0x110 [smc] > smc_find_rdma_v2_device_serv+0x18f/0x240 [smc] > ? smc_vlan_by_tcpsk+0x7e/0xe0 [smc] > smc_listen_find_device+0x1dd/0x2b0 [smc] > smc_listen_work+0x30f/0x580 [smc] > process_one_work+0x18c/0x340 > worker_thread+0x242/0x360 > kthread+0xe7/0x220 > ret_from_fork+0x13a/0x160 > ret_from_fork_asm+0x1a/0x30 > > > If the software RoCE device is used, ibdev->dma_device is a null pointer. > As a result, the problem occurs. Null pointer detection is added to > prevent problems. > > Fixes: 0ef69e788411c ("net/smc: optimize for smc_sndbuf_sync_sg_for_device and smc_rmb_sync_sg_for_cpu") > Signed-off-by: Liu Jian > --- > v1->v2: > move the check outside of loop. > net/smc/smc_ib.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c > index 53828833a3f7..a42ef3f77b96 100644 > --- a/net/smc/smc_ib.c > +++ b/net/smc/smc_ib.c > @@ -742,6 +742,9 @@ bool smc_ib_is_sg_need_sync(struct smc_link *lnk, > unsigned int i; > bool ret = false; > > + if (!lnk->smcibdev->ibdev->dma_device) > + return ret; > + > /* for now there is just one DMA address */ > for_each_sg(buf_slot->sgt[lnk->link_idx].sgl, sg, > buf_slot->sgt[lnk->link_idx].nents, i) { LGTM. Reviewed-by: Guangguan Wang