From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail5.25mail.st (mail5.25mail.st [74.50.62.9]) (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 05A071EB2A; Fri, 5 Apr 2024 05:46:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.50.62.9 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712296000; cv=none; b=AxiYMNT0aI+7ObvF+BXYwBkdqccVr9yIxBKqyd+tFarEjkZgxtUTe3YnblaqgNgXej6iiIr5lKPa8d6QeQbr3atPIxjh/RSl8twujWwur9iOM+bg3ydgjWFkK7BjlPVsJH1ofV3VQN+H+OIffUJCa4OWYHMv/LjdUx8xla8p7yM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712296000; c=relaxed/simple; bh=GELzFyw10kbJwOThW65zaSoLGBpg9a4ALZJAr38/+Ik=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=BquYIxwExC5NC+KV33dh+cetoAxqDJiU90Z2jC0QJpZtG/5xC3BqbKQfrXAI28ncofri2nUKfoTVEtLWRwYjz50DaujY6zGO8fsvodZHylyOEZDcmCr/nGIdAuuB5wtrZpiSoPIN5vvGonmMxkZeQ1CPgFkq9zlQ50bPzwHKZK8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=atomide.com; spf=fail smtp.mailfrom=atomide.com; dkim=pass (2048-bit key) header.d=atomide.com header.i=@atomide.com header.b=DBETiGHy; arc=none smtp.client-ip=74.50.62.9 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=atomide.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=atomide.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=atomide.com header.i=@atomide.com header.b="DBETiGHy" Received: from localhost (91-158-86-216.elisa-laajakaista.fi [91.158.86.216]) by mail5.25mail.st (Postfix) with ESMTPSA id 6041060333; Fri, 5 Apr 2024 05:46:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=atomide.com; s=25mailst; t=1712295998; bh=GELzFyw10kbJwOThW65zaSoLGBpg9a4ALZJAr38/+Ik=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DBETiGHyvP2bnLvQgtNZaxqY2pb1Opk/nD096aHz2hvhC4waeHqvwTaiVKitlsCDm 8ZdNYQzl9KpGKMaa/C+hQeR3b7jJO3g1rER/QI9R/CzvHcquHyUDp/6Z9SM7N9hcVx N5VMa2dNNBiNM8bbN6hQyIMpgH7C6BLVpupbtpvydVz8TLidalND9bIOCIcEUJKu9v p1iCL8/8zDsiBjdq9+v7fR9IFpVc/ax7PK7CHpY3719nvi8GdsJkF4fZkcEBeU9xtF 3FbQVCh7WfLPImiAODkZLq4BVmL2mq7TjcgcCh0JIf+XV86HCYBoZ+TDp8WuXISC4i 0VOM2YTxEbPMw== Date: Fri, 5 Apr 2024 08:46:17 +0300 From: Tony Lindgren To: Andy Shevchenko Cc: kernel test robot , Yicong Yang , oe-lkp@lists.linux.dev, lkp@intel.com, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , stable , linux-serial@vger.kernel.org Subject: Re: [linus:master] [serial] 43066e3222: BUG:kernel_NULL_pointer_dereference,address Message-ID: <20240405054617.GQ5132@atomide.com> References: <202404031607.2e92eebe-lkp@intel.com> <20240404065415.GO5132@atomide.com> Precedence: bulk X-Mailing-List: linux-kernel@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: * Andy Shevchenko [240404 14:34]: > On Thu, Apr 04, 2024 at 09:54:15AM +0300, Tony Lindgren wrote: > > * Andy Shevchenko [240403 14:00]: > > > Probably we need to check if the port is still open... > > > > > > P.S. AFAIU the state / xmit is invalid pointer or so. > > > > > > Culprit line: serial_out(up, UART_TX, xmit->buf[xmit->tail]); > > > > Maybe we can set UPF_DEAD a bit earlier as below? > > We should do this under port_mutex. Otherwise we replace one race by another. Oh right.. And adding some better check in addition to UPF_DEAD would be better. Regards, Tony