From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80C0BC742B9 for ; Fri, 12 Jul 2019 12:30:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A1B2216C8 for ; Fri, 12 Jul 2019 12:30:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934639; bh=mEHwNLg4gK3ziQCCf0esvVZ619U3KOGInEuHUxF4okQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ymZlVHNxPfexAI+/O5Rk5BiiSpWesHFtMFTmcBxyUmJtebgELUQV2h6gsukTMmSLL 7GQE2dYRRhjmNIFy6asgt0URTaBFFeqhT8QnlWNtNtgF1LdL6epc1h5bmDKKbbnm1n cNeK/+V93OfiByF39OKo+i00/hVLQ4RgCCyqHFjM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728246AbfGLMah (ORCPT ); Fri, 12 Jul 2019 08:30:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:46552 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729167AbfGLMah (ORCPT ); Fri, 12 Jul 2019 08:30:37 -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 D61A1208E4; Fri, 12 Jul 2019 12:30:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934636; bh=mEHwNLg4gK3ziQCCf0esvVZ619U3KOGInEuHUxF4okQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p8m4xNyxOeJEI6C0W+QxT+ipRrDFVh64bl/VChfk4i+ItvVlVPzZA4Z48TBDmLhca 3P87qVfjkVBF5bL3qRjvlo1JLx4BDiLg5o4ql55zkko3pkYg/QGPCwEW0P+GZbFlpd 658VWVXn/REqIwSov9tJ9k8b0KSTL77s+L1xX9HE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christian Lamparter , Kalle Valo Subject: [PATCH 5.1 118/138] p54: fix crash during initialization Date: Fri, 12 Jul 2019 14:19:42 +0200 Message-Id: <20190712121633.274431577@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190712121628.731888964@linuxfoundation.org> References: <20190712121628.731888964@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Christian Lamparter commit 1645ab931998b39aed5761f095956f0b10a6362f upstream. This patch fixes a crash that got introduced when the mentioned patch replaced the direct list_head access with skb_peek_tail(). When the device is starting up, there are no entries in the queue, so previously to "Use skb_peek_tail() instead..." the target_skb would end up as the tail and head pointer which then could be used by __skb_queue_after to fill the empty queue. With skb_peek_tail() in its place will instead just return NULL which then causes a crash in the __skb_queue_after(). | BUG: unable to handle kernel NULL pointer dereference at 000000 | #PF error: [normal kernel read fault] | PGD 0 P4D 0 | Oops: 0000 [#1] SMP PTI | CPU: 0 PID: 12 Comm: kworker/0:1 Tainted: GO 5.1.0-rc7-wt+ #218 | Hardware name: MSI MS-7816/Z87-G43 (MS-7816), BIOS V1.11 05/09/2015 | Workqueue: events request_firmware_work_func | RIP: 0010:p54_tx_pending+0x10f/0x1b0 [p54common] | Code: 78 06 80 78 28 00 74 6d <48> 8b 07 49 89 7c 24 08 49 89 04 24 4 | RSP: 0018:ffffa81c81927d90 EFLAGS: 00010086 | RAX: ffff9bbaaf131048 RBX: 0000000000020670 RCX: 0000000000020264 | RDX: ffff9bbaa976d660 RSI: 0000000000000202 RDI: 0000000000000000 | RBP: ffff9bbaa976d620 R08: 00000000000006c0 R09: ffff9bbaa976d660 | R10: 0000000000000000 R11: ffffe8480dbc5900 R12: ffff9bbb45e87700 | R13: ffff9bbaa976d648 R14: ffff9bbaa976d674 R15: ffff9bbaaf131048 | FS: 0000000000000000(0000) GS:ffff9bbb5ec00000(0000) knlGS:00000 | CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 | CR2: 0000000000000000 CR3: 00000003695fc003 CR4: 00000000001606f0 | Call Trace: | p54_download_eeprom+0xbe/0x120 [p54common] | p54_read_eeprom+0x7f/0xc0 [p54common] | p54u_load_firmware_cb+0xe0/0x160 [p54usb] | request_firmware_work_func+0x42/0x80 | process_one_work+0x1f5/0x3f0 | worker_thread+0x28/0x3c0 Cc: stable@vger.kernel.org Fixes: e3554197fc8f ("p54: Use skb_peek_tail() instead of direct head pointer accesses.") Signed-off-by: Christian Lamparter Signed-off-by: Kalle Valo Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/intersil/p54/txrx.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/net/wireless/intersil/p54/txrx.c +++ b/drivers/net/wireless/intersil/p54/txrx.c @@ -142,7 +142,10 @@ static int p54_assign_address(struct p54 unlikely(GET_HW_QUEUE(skb) == P54_QUEUE_BEACON)) priv->beacon_req_id = data->req_id; - __skb_queue_after(&priv->tx_queue, target_skb, skb); + if (target_skb) + __skb_queue_after(&priv->tx_queue, target_skb, skb); + else + __skb_queue_head(&priv->tx_queue, skb); spin_unlock_irqrestore(&priv->tx_queue.lock, flags); return 0; }