From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) (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 E7CFA2A1BB; Thu, 8 May 2025 18:24:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.13 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746728661; cv=none; b=Vx4d6IQiGc8Zcg2wbk37Y2bbN2llAhy1OVVY6aKOuVymga4CR2jeEfUIHftBsXfCbKpHf/OsDQPntBDwl3CyoN0LRnT6ip0g1J+XYFupMYJbt9I8lWQNEbIGiYqyEq/GeF+ygXYjCuzvJPAioBo/z57yRZAxqB4j1DIGDCSGl2Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746728661; c=relaxed/simple; bh=wy7Hm7WWE6KUctlNRNHdG2pofR8kbdBCRVqncmV5x1A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ePQJ/zmea8+pKV2NI+qvQU8mGBSwoDV+U/k7fDXTG8RLjq0qFFWYmeVz81CBGoU0NNMIeEJHSNvcjGEUDjG8r0inOAvgSMoYZVPXo5dj6mt+QskdVD/48L9+pKXbitq77/J39wf0mKsF8jtcXstrBOu4zFZzBHxxPEHdKciAzI0= 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=h0UhHSeZ; arc=none smtp.client-ip=198.175.65.13 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="h0UhHSeZ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1746728660; x=1778264660; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=wy7Hm7WWE6KUctlNRNHdG2pofR8kbdBCRVqncmV5x1A=; b=h0UhHSeZ4T2gG2v/e+5U7cm2gDwuYQpIAjOTc47pTNrx8U0E1G6kPO8v bPvN1299qjiEcnJQsQxPVntzZeIgs6cWEv7hkZ9Etc5DRbtr3kBmMdpHp gPUdJ7PhxDV972iES1qiG3Twqprgt+AliNFDuJJtuNf3BxeIKvFKuzNMR GjSWibfbrWpBc2gG1UHpQnuZqOtf8r2YlJU5V3mN9QNNFn5I/RYQfiiZA vVsH1jzdV/DzV9jVUaXFK3BKxqhPJmaGiaemIsZmTyIgtuV6MVD2p3+X0 5QvlF8BtmquhwJIFOmN6xM2EyNnmw1ETRiLZM7Ly5IwWse76OLAt7Euu6 w==; X-CSE-ConnectionGUID: lm/P4yWbR4WfjXCQrCxDMw== X-CSE-MsgGUID: IYrYpp4ySQ2cIANVcfbTBw== X-IronPort-AV: E=McAfee;i="6700,10204,11427"; a="59528712" X-IronPort-AV: E=Sophos;i="6.15,272,1739865600"; d="scan'208";a="59528712" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 May 2025 11:24:19 -0700 X-CSE-ConnectionGUID: dqhiX814RE+mTzdjGP/elQ== X-CSE-MsgGUID: TxG6ibazRVKDkmcTOQouyA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.15,272,1739865600"; d="scan'208";a="136385923" Received: from bergbenj-mobl1.ger.corp.intel.com (HELO [10.245.246.123]) ([10.245.246.123]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 May 2025 11:24:15 -0700 Message-ID: Date: Thu, 8 May 2025 21:25:25 +0300 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4] ASoC: SOF: Intel: hda: Fix UAF when reloading module To: Tavian Barnes , linux-sound@vger.kernel.org Cc: Liam Girdwood , Bard Liao , Ranjani Sridharan , Daniel Baluta , Kai Vehmanen , Pierre-Louis Bossart , Mark Brown , Jaroslav Kysela , Takashi Iwai , Peter Zijlstra , sound-open-firmware@alsa-project.org, linux-kernel@vger.kernel.org References: <832255bf606f9ddcf45167d3f066d603d707731a.1746713571.git.tavianator@tavianator.com> Content-Language: en-US From: =?UTF-8?Q?P=C3=A9ter_Ujfalusi?= In-Reply-To: <832255bf606f9ddcf45167d3f066d603d707731a.1746713571.git.tavianator@tavianator.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 08/05/2025 18:21, Tavian Barnes wrote: > hda_generic_machine_select() appends -idisp to the tplg filename by > allocating a new string with devm_kasprintf(), then stores the string > right back into the global variable snd_soc_acpi_intel_hda_machines. > When the module is unloaded, this memory is freed, resulting in a global > variable pointing to freed memory. Reloading the module then triggers > a use-after-free: > > BUG: KFENCE: use-after-free read in string+0x48/0xe0 > > Use-after-free read at 0x00000000967e0109 (in kfence-#99): > string+0x48/0xe0 > vsnprintf+0x329/0x6e0 > devm_kvasprintf+0x54/0xb0 > devm_kasprintf+0x58/0x80 > hda_machine_select.cold+0x198/0x17a2 [snd_sof_intel_hda_generic] > sof_probe_work+0x7f/0x600 [snd_sof] > process_one_work+0x17b/0x330 > worker_thread+0x2ce/0x3f0 > kthread+0xcf/0x100 > ret_from_fork+0x31/0x50 > ret_from_fork_asm+0x1a/0x30 > > kfence-#99: 0x00000000198a940f-0x00000000ace47d9d, size=64, cache=kmalloc-64 > > allocated by task 333 on cpu 8 at 17.798069s (130.453553s ago): > devm_kmalloc+0x52/0x120 > devm_kvasprintf+0x66/0xb0 > devm_kasprintf+0x58/0x80 > hda_machine_select.cold+0x198/0x17a2 [snd_sof_intel_hda_generic] > sof_probe_work+0x7f/0x600 [snd_sof] > process_one_work+0x17b/0x330 > worker_thread+0x2ce/0x3f0 > kthread+0xcf/0x100 > ret_from_fork+0x31/0x50 > ret_from_fork_asm+0x1a/0x30 > > freed by task 1543 on cpu 4 at 141.586686s (6.665010s ago): > release_nodes+0x43/0xb0 > devres_release_all+0x90/0xf0 > device_unbind_cleanup+0xe/0x70 > device_release_driver_internal+0x1c1/0x200 > driver_detach+0x48/0x90 > bus_remove_driver+0x6d/0xf0 > pci_unregister_driver+0x42/0xb0 > __do_sys_delete_module+0x1d1/0x310 > do_syscall_64+0x82/0x190 > entry_SYSCALL_64_after_hwframe+0x76/0x7e > > Fix it by copying the match array with devm_kmemdup_array() before we > modify it. > > Fixes: 5458411d7594 ("ASoC: SOF: Intel: hda: refactoring topology name fixup for HDA mach") > Suggested-by: Péter Ujfalusi" > Signed-off-by: Tavian Barnes > --- > v4: Copy the whole array, including the sentinel. > > v3: Copy the whole machine struct instead so we can safely modify it > (instead of storing the name in pdata->tplg_filename, breaking other > fixups). The problem with v2 was pointed out by Bard Liao, with the > alternative fix suggested by Péter Ujfalusi. > > v2: Typo fix. > > sound/soc/sof/intel/hda.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/sound/soc/sof/intel/hda.c b/sound/soc/sof/intel/hda.c > index b34e5fdf10f1..13ecb9473eb6 100644 > --- a/sound/soc/sof/intel/hda.c > +++ b/sound/soc/sof/intel/hda.c > @@ -1049,7 +1049,21 @@ static void hda_generic_machine_select(struct snd_sof_dev *sdev, > if (!*mach && codec_num <= 2) { > bool tplg_fixup = false; > > - hda_mach = snd_soc_acpi_intel_hda_machines; > + /* > + * make a local copy of the match array since we might > + * be modifying it > + */ > + hda_mach = devm_kmemdup_array(sdev->dev, > + snd_soc_acpi_intel_hda_machines, > + 2 /* we have one entry + sentinel in the array */, I would prefer the comment after the comma. and I just noticed that my suggestion had it wrong as well, sorry. With that you can add my: Acked-by: Peter Ujfalusi > + sizeof(snd_soc_acpi_intel_hda_machines[0]), > + GFP_KERNEL); > + if (!hda_mach) { > + dev_err(bus->dev, > + "%s: failed to duplicate the HDA match table\n", > + __func__); > + return; > + } > > dev_info(bus->dev, "using HDA machine driver %s now\n", > hda_mach->drv_name); -- Péter