From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.18]) (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 D0591182D8; Thu, 4 Apr 2024 14:42:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712241757; cv=none; b=Aq1nLj8KyZzwe1Ortaduxs1nIVqJbNaUOAQMLlT60mGZkkvlNAiywwaKKEBMDkVqAvD2hX+g1TSKS0LetdBxfPUoIECzTudcAtEHaFonjb9psb+jPl+nncHOrX9nM/WoCnd+/FDEPJ1LbAOcA0ElAQPnpL40masNbKEXAiwwTbs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712241757; c=relaxed/simple; bh=UTGGGrM2F/ayC3lHF5933J74dgJ9/c3oQCAPyRO10bI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=INwlwjjvoRsChwgyKCmmRhAYd2snm42+5qrsCFeGDK8mnKJ7tVCYDGL2Kja/TsxdjDsPVpZZ87A1XVciPonbDkqQ//7/EVEBkE1bRHKS4/4rjHvtqHqyfMS5BLkEhas3hG3cpcwK2S/2HCQz1TwApaxA43ph3U0wX26ICpgj6S8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=XiJyVHzv; arc=none smtp.client-ip=198.175.65.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="XiJyVHzv" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1712241756; x=1743777756; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=UTGGGrM2F/ayC3lHF5933J74dgJ9/c3oQCAPyRO10bI=; b=XiJyVHzvgRKGstqwQMx2RTJqK6sPFiMvw8pC2VNKDGz1J/qCHPXeGCgT TR7TrpspnngN0pLLg/kl+O0/lxBKrHWVL+Yjc0aiWKkKxRHL/UqRmGVqp kSaMAvHrvVjGDrpvnhF8rlgW8teMl4YeL0Dt+WSKraxs/EyFGf4SuZvmy FKbpFijBKaGpzjc2KRM9zmtlxrIrviR5GAKh2TtybF+TjUEVyDAo28ACc 509wnpGzg9YdXjdw5qAFQKp0RnwHdIeDUgEKfL7T0KoIXcF/aZsVtNsCi aLLfK05Uqr/5Fl0cC5T3O/YlBTxuYCxWQMvrWWukXKCJl2lDKxlxnmgPY A==; X-CSE-ConnectionGUID: 365tAoy/TBqNXnhBpMAZ4A== X-CSE-MsgGUID: bQHJr8d+T3uBXn/TyIDxdw== X-IronPort-AV: E=McAfee;i="6600,9927,11034"; a="7690168" X-IronPort-AV: E=Sophos;i="6.07,179,1708416000"; d="scan'208";a="7690168" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Apr 2024 07:42:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,11034"; a="915220229" X-IronPort-AV: E=Sophos;i="6.07,179,1708416000"; d="scan'208";a="915220229" Received: from smile.fi.intel.com (HELO smile) ([10.237.72.54]) by fmsmga002.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Apr 2024 07:42:32 -0700 Received: from andy by smile with local (Exim 4.97) (envelope-from ) id 1rsOIP-00000001UBc-1qNB; Thu, 04 Apr 2024 17:42:29 +0300 Date: Thu, 4 Apr 2024 17:42:29 +0300 From: Andy Shevchenko To: Tony Lindgren 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: 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: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo On Thu, Apr 04, 2024 at 02:59:19PM +0300, Andy Shevchenko wrote: > 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]); > > xmit.buf seems to be NULL, that's why this fails. > > > Maybe we can set UPF_DEAD a bit earlier as below? > > Lemme perform some tests later today. Okay, so far it doesn't fix the issue AFAICT. The only reliable one right now to me is clearing circ buffer before NULLifying it. I'll send a formal patch. -- With Best Regards, Andy Shevchenko