From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 86DBD30F94A; Tue, 9 Sep 2025 09:45:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757411137; cv=none; b=rPNtMSjVZotAgT5uj+deRtQaBRDmZOM5mxdm0cxPDFbJ+nJ1w6jFHlhP3IHHILUySndXR5kVbvHEp9e8OAjVTlW2Tc2VhyWT+u1pYvVp/zjBeY1fOEuitm+YOwQfywj5Jhfxxn2/oYDwVXq4SHkCzrbFx8JDfxa6tgazbWuVEGM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757411137; c=relaxed/simple; bh=QUvP8GINuCzSF7JPaWUyPUnNE7WZ2BGlzy60uTCAee4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=C3ndxPEZuZSvcmoN61L/KvVVrWOA+HMVhVHf7Icaem0XIscWJk6T1K2VxdXs8jXo88NTSNKmIwP+qzFGH4adV+5sXl7sMkDIOKBvGzLRbWLWTNB4Re50rUfM294jfLSwgPvG5ULX1WLJ/swYM4cBJpp5vG7l+gMgK/HGdupCX/0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jttF35M4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jttF35M4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97723C4CEF4; Tue, 9 Sep 2025 09:45:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757411137; bh=QUvP8GINuCzSF7JPaWUyPUnNE7WZ2BGlzy60uTCAee4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=jttF35M4NSuhz5upmy8/c9ZrRK2u7fT59c1LlHk0Yzx4DWtfMXJAL53GBruztjArX DCT1hUaEPiv28UP+nP4618fMUegp/l4WQdFigfky2Hlvpc+Vciyc6PTEyxcw0kcGjB 7t38n6GJOzJG/4LPMU0n6HUk9ot3Pmcj0Jwm3iyt7nurt+AC5lqsu7LwtNKoLKLSGE EwYaF6iGgKDDCz5D2Gp0utYfRj0s4l6dh5l3Cl5ZkZwxhyMQQpXPDDqkr4trE0OYos hY26oLB2zfrWNh1wlODgIeGGeaXDjiHXr60wxOdrZLIaWjAR1lI6CAuIDX6PPW6Vn0 5plBbpkwoYfTA== Date: Tue, 9 Sep 2025 12:45:32 +0300 From: Leon Romanovsky To: Liu Jian Cc: 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, guangguan.wang@linux.alibaba.com, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [PATCH net v2] net/smc: fix one NULL pointer dereference in smc_ib_is_sg_need_sync() Message-ID: <20250909094532.GD341237@unreal> References: <20250828124117.2622624-1-liujian56@huawei.com> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250828124117.2622624-1-liujian56@huawei.com> On Thu, Aug 28, 2025 at 08:41:17PM +0800, Liu Jian wrote: > 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; Please use ib_uses_virt_dma() function for that. It is clearly stated in the code: 2784 struct ib_device { 2785 /* Do not access @dma_device directly from ULP nor from HW drivers. */ 2786 struct device *dma_device; Thanks > + > /* 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) { > -- > 2.34.1 > >