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[209.132.180.67]) by mx.google.com with ESMTP id k33si7761858pld.359.2019.07.12.05.38.14; Fri, 12 Jul 2019 05:38:29 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b="k/6pw0vO"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728969AbfGLMgF (ORCPT + 99 others); Fri, 12 Jul 2019 08:36:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:52466 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729597AbfGLMdW (ORCPT ); Fri, 12 Jul 2019 08:33:22 -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 D4F632084B; Fri, 12 Jul 2019 12:33:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934801; bh=v1zlSdtSYkTVOHfwqqXwCinbA7/ajH/Qsb0rE7aKEtI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k/6pw0vOZ7ztc/JBX6BRO15Af5CsLKPrBii0/6FvbK5soNrPgcbN/39kQlumf/cCt bPzlwvAKWMd3/sM01+X61lyJV+fQIitK2IwJ1tP83INQSjHVDoYO2sWeaBwwlIt67V 9aTisL/AQFbYPhaPkxwwAxGoctaE46KYqs9gj7nU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christian Lamparter , Kalle Valo Subject: [PATCH 5.2 34/61] p54: fix crash during initialization Date: Fri, 12 Jul 2019 14:19:47 +0200 Message-Id: <20190712121622.438830740@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190712121620.632595223@linuxfoundation.org> References: <20190712121620.632595223@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -139,7 +139,10 @@ 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; }