From patchwork Tue Oct 1 15:39:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 11169121 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 469581599 for ; Tue, 1 Oct 2019 15:39:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 265A621855 for ; Tue, 1 Oct 2019 15:39:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569944363; bh=c3rVfzYtsTWo4wLjYthp4mUIgCkjj9GL3anMJAQORLA=; h=Date:From:To:Cc:Subject:List-ID:From; b=SFmyIcR9kofJUTCeaWj3EIpnKE039VU5lZt0+xy1gTpJ+Kz3iW/Ro5N5u7q0yXl+C h50G0FvBuXjPjodL2GSSzb4nMl6mnmxKkFjkTAOfi1ja9bS6k7n0Zwc47WN37Di5zq 0s6r3WqVCexTse/Fe0qeRrJRgPMVxeYJdAIaJhDI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389647AbfJAPjW (ORCPT ); Tue, 1 Oct 2019 11:39:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:58234 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389528AbfJAPjW (ORCPT ); Tue, 1 Oct 2019 11:39:22 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 149FC2133F; Tue, 1 Oct 2019 15:39:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569944359; bh=c3rVfzYtsTWo4wLjYthp4mUIgCkjj9GL3anMJAQORLA=; h=Date:From:To:Cc:Subject:From; b=TfAsmXYJ+0g0gOQO2JSeJlwU6hWMx1ZrHscboe+EMZ3vqRrHaYv6oTCd30qkw353r McoBGqPJ6pbxbbIoE1/UXHv/EvxMcHUfkwcqGaNq+bieHS+EGBsodcn13t3I1J2beW 4/0Mob8YGX65JYDYC3TlRvGaAboL9rGGXX9/kMQ0= Date: Tue, 1 Oct 2019 17:39:17 +0200 From: Greg KH To: Potnuri Bharat Teja , Doug Ledford , Jason Gunthorpe Cc: linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, Nicolas Waisman Subject: [PATCH] cxgb4: do not dma memory off of the stack Message-ID: <20191001153917.GA3498459@kroah.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Nicolas pointed out that the cxgb4 driver is doing dma off of the stack, which is generally considered a very bad thing. On some architectures it could be a security problem, but odds are none of them actually run this driver, so it's just a "normal" bug. Resolve this by allocating the memory for a message off of the heap instead of the stack. kmalloc() always will give us a proper memory location that DMA will work correctly from. Reported-by: Nicolas Waisman Signed-off-by: Greg Kroah-Hartman Tested-by: Potnuri Bharat Teja --- Note, test-built only, I don't have this hardware to actually run this code at all. diff --git a/drivers/infiniband/hw/cxgb4/mem.c b/drivers/infiniband/hw/cxgb4/mem.c index aa772ee0706f..b2bd3de81dcd 100644 --- a/drivers/infiniband/hw/cxgb4/mem.c +++ b/drivers/infiniband/hw/cxgb4/mem.c @@ -275,13 +275,17 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry, struct sk_buff *skb, struct c4iw_wr_wait *wr_waitp) { int err; - struct fw_ri_tpte tpt; + struct fw_ri_tpte *tpt; u32 stag_idx; static atomic_t key; if (c4iw_fatal_error(rdev)) return -EIO; + tpt = kmalloc(sizeof(*tpt), GFP_KERNEL); + if (!tpt) + return -ENOMEM; + stag_state = stag_state > 0; stag_idx = (*stag) >> 8; @@ -305,28 +309,28 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry, /* write TPT entry */ if (reset_tpt_entry) - memset(&tpt, 0, sizeof(tpt)); + memset(tpt, 0, sizeof(*tpt)); else { - tpt.valid_to_pdid = cpu_to_be32(FW_RI_TPTE_VALID_F | + tpt->valid_to_pdid = cpu_to_be32(FW_RI_TPTE_VALID_F | FW_RI_TPTE_STAGKEY_V((*stag & FW_RI_TPTE_STAGKEY_M)) | FW_RI_TPTE_STAGSTATE_V(stag_state) | FW_RI_TPTE_STAGTYPE_V(type) | FW_RI_TPTE_PDID_V(pdid)); - tpt.locread_to_qpid = cpu_to_be32(FW_RI_TPTE_PERM_V(perm) | + tpt->locread_to_qpid = cpu_to_be32(FW_RI_TPTE_PERM_V(perm) | (bind_enabled ? FW_RI_TPTE_MWBINDEN_F : 0) | FW_RI_TPTE_ADDRTYPE_V((zbva ? FW_RI_ZERO_BASED_TO : FW_RI_VA_BASED_TO))| FW_RI_TPTE_PS_V(page_size)); - tpt.nosnoop_pbladdr = !pbl_size ? 0 : cpu_to_be32( + tpt->nosnoop_pbladdr = !pbl_size ? 0 : cpu_to_be32( FW_RI_TPTE_PBLADDR_V(PBL_OFF(rdev, pbl_addr)>>3)); - tpt.len_lo = cpu_to_be32((u32)(len & 0xffffffffUL)); - tpt.va_hi = cpu_to_be32((u32)(to >> 32)); - tpt.va_lo_fbo = cpu_to_be32((u32)(to & 0xffffffffUL)); - tpt.dca_mwbcnt_pstag = cpu_to_be32(0); - tpt.len_hi = cpu_to_be32((u32)(len >> 32)); + tpt->len_lo = cpu_to_be32((u32)(len & 0xffffffffUL)); + tpt->va_hi = cpu_to_be32((u32)(to >> 32)); + tpt->va_lo_fbo = cpu_to_be32((u32)(to & 0xffffffffUL)); + tpt->dca_mwbcnt_pstag = cpu_to_be32(0); + tpt->len_hi = cpu_to_be32((u32)(len >> 32)); } err = write_adapter_mem(rdev, stag_idx + (rdev->lldi.vr->stag.start >> 5), - sizeof(tpt), &tpt, skb, wr_waitp); + sizeof(*tpt), tpt, skb, wr_waitp); if (reset_tpt_entry) { c4iw_put_resource(&rdev->resource.tpt_table, stag_idx); @@ -334,6 +338,7 @@ static int write_tpt_entry(struct c4iw_rdev *rdev, u32 reset_tpt_entry, rdev->stats.stag.cur -= 32; mutex_unlock(&rdev->stats.lock); } + kfree(tpt); return err; }