From patchwork Thu Feb 1 08:10:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Vacek X-Patchwork-Id: 13540776 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 BA5581586D3 for ; Thu, 1 Feb 2024 08:11:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706775083; cv=none; b=m9rUC+Cv8lRV49IqPKFf+Ta1MdOmir26lWwR9a5vmUG6pFil3nODvaimsN8ElAmE/Xnu8JYqWr5YA2uQBn+/Y31tR8o3EqOQKTK+6QlaIa8+aV5gE3lXzy3vvQMAHrk66Vmv/ar5ue2FJpy84CMya6CWqdyiYBfd+BTt0hls2pI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706775083; c=relaxed/simple; bh=y1w5sJ8ktbHEe0F3UYcqGu1KS6iUPE0CBc0UPiD+WCw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GMb7Z9nUzuR1fIm+qTQ7gbSaDnY9SDqldd8BEHL0H5bJAuPabqZQAl8n658fAbPvJsWMnJR6tx67gFxEhy/UyAq08Z3Q9gDhK7raHxEZuovO/rTAbstZrjpZrSvMg0PxhTSO0l6lPA7Dr0r8Yn4FRHj+OdOKzDtuOh1UU8ag2l8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=HXMHlcnM; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="HXMHlcnM" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1706775079; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TQDdRV2tMPG+6nfJCtzHbTe1EEi3qaM2yI8qVm5kEZY=; b=HXMHlcnMSwyP8Rco1RThmL9FOcPHMvGizTzcZzwXRzshuUcOuYjv+Ys0bbC7fz3Am/+YAr y0Sy8IXDJDKNgnkVDK58w4hnqktToBT3anjWibY9F44kXeFemBdRh8bYFgt6QHbM7CXQnD PbMP74Hn9h0raDAsFOwSEBHGdX/+D9c= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-582-XHBq3RvKOoKY9F01Y5fe4w-1; Thu, 01 Feb 2024 03:11:14 -0500 X-MC-Unique: XHBq3RvKOoKY9F01Y5fe4w-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 09E542932486; Thu, 1 Feb 2024 08:11:14 +0000 (UTC) Received: from metal.redhat.com (unknown [10.45.224.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id 22FDE492BE2; Thu, 1 Feb 2024 08:11:11 +0000 (UTC) From: Daniel Vacek To: Dennis Dalessandro , Jason Gunthorpe , Leon Romanovsky , Patrick Kelsey , Brendan Cunningham Cc: Daniel Vacek , stable@vger.kernel.org, Mats Kronberg , linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] IB/hfi1: Fix sdma.h tx->num_descs off-by-one error (take two) Date: Thu, 1 Feb 2024 09:10:08 +0100 Message-ID: <20240201081009.1109442-1-neelx@redhat.com> In-Reply-To: <20240126152125.869509-1-neelx@redhat.com> References: <20240126152125.869509-1-neelx@redhat.com> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 Unfortunately the commit `fd8958efe877` introduced another error causing the `descs` array to overflow. This reults in further crashes easily reproducible by `sendmsg` system call. [ 1080.836473] general protection fault, probably for non-canonical address 0x400300015528b00a: 0000 [#1] PREEMPT SMP PTI [ 1080.869326] RIP: 0010:hfi1_ipoib_build_ib_tx_headers.constprop.0+0xe1/0x2b0 [hfi1] --- [ 1080.974535] Call Trace: [ 1080.976990] [ 1081.021929] hfi1_ipoib_send_dma_common+0x7a/0x2e0 [hfi1] [ 1081.027364] hfi1_ipoib_send_dma_list+0x62/0x270 [hfi1] [ 1081.032633] hfi1_ipoib_send+0x112/0x300 [hfi1] [ 1081.042001] ipoib_start_xmit+0x2a9/0x2d0 [ib_ipoib] [ 1081.046978] dev_hard_start_xmit+0xc4/0x210 -- [ 1081.148347] __sys_sendmsg+0x59/0xa0 crash> ipoib_txreq 0xffff9cfeba229f00 struct ipoib_txreq { txreq = { list = { next = 0xffff9cfeba229f00, prev = 0xffff9cfeba229f00 }, descp = 0xffff9cfeba229f40, coalesce_buf = 0x0, wait = 0xffff9cfea4e69a48, complete = 0xffffffffc0fe0760 , packet_len = 0x46d, tlen = 0x0, num_desc = 0x0, desc_limit = 0x6, next_descq_idx = 0x45c, coalesce_idx = 0x0, flags = 0x0, descs = {{ qw = {0x8024000120dffb00, 0x4} # SDMA_DESC0_FIRST_DESC_FLAG (bit 63) }, { qw = { 0x3800014231b108, 0x4} }, { qw = { 0x310000e4ee0fcf0, 0x8} }, { qw = { 0x3000012e9f8000, 0x8} }, { qw = { 0x59000dfb9d0000, 0x8} }, { qw = { 0x78000e02e40000, 0x8} }} }, sdma_hdr = 0x400300015528b000, <<< invalid pointer in the tx request structure sdma_status = 0x0, SDMA_DESC0_LAST_DESC_FLAG (bit 62) complete = 0x0, priv = 0x0, txq = 0xffff9cfea4e69880, skb = 0xffff9d099809f400 } If an SDMA send consists of exactly 6 descriptors and requires dword padding (in the 7th descriptor), the sdma_txreq descriptor array is not properly expanded and the packet will overflow into the container structure. This results in a panic when the send completion runs. The exact panic varies depending on what elements of the container structure get corrupted. The fix is to use the correct expression in _pad_sdma_tx_descs() to test the need to expand the descriptor array. With this patch the crashes are no longer reproducible and the machine is stable. Fixes: fd8958efe877 ("IB/hfi1: Fix sdma.h tx->num_descs off-by-one errors") Cc: stable@vger.kernel.org Reported-by: Mats Kronberg Tested-by: Mats Kronberg Signed-off-by: Daniel Vacek --- Changes in v2: - Dropped the unrelated cleanups. - Improved commit message as suggested by Dennis Dalessandro drivers/infiniband/hw/hfi1/sdma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c index 6e5ac2023328a..b67d23b1f2862 100644 --- a/drivers/infiniband/hw/hfi1/sdma.c +++ b/drivers/infiniband/hw/hfi1/sdma.c @@ -3158,7 +3158,7 @@ int _pad_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx) { int rval = 0; - if ((unlikely(tx->num_desc + 1 == tx->desc_limit))) { + if ((unlikely(tx->num_desc == tx->desc_limit))) { rval = _extend_sdma_tx_descs(dd, tx); if (rval) { __sdma_txclean(dd, tx);