From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.8]) (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 31433320A32; Wed, 26 Nov 2025 09:50:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764150637; cv=none; b=nvESxdmUYAQ5sszqQ35lnOXQ/R9C/Rb6xBKNS1+KX9Mvj64Gc6TpXIfufF+zrLg4dof7jwwlqNDmiIjqDg+XTvVd9VsR6O9wowIVasb784jDIGznWUWN0PYuIo0/mjdr2ViuWgNfn//Zfyp9sWsGEFwXAPffQdkDvp5ORG9JemI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764150637; c=relaxed/simple; bh=njWROoXaInge3OibSMvthGyMUZf/RJpqVOM51CCCZXE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rWw4VSsEBn2Dx3OtZN/QeNdZnaEfBaTYJlnG7mJ+REAPcOuRqYxzSP2Q3akIlC/mBcGSO47e5R088HGDQU5iRbdz4gPi8nm35RayAeApR8JMwRIObG1weIo1rYZcdQei9J6Fi1CD+lB0WhLxH/PZlPUArVyGTLFGY77Gz4ldVN8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=TKo8Ydkz; arc=none smtp.client-ip=192.198.163.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass 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="TKo8Ydkz" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1764150635; x=1795686635; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=njWROoXaInge3OibSMvthGyMUZf/RJpqVOM51CCCZXE=; b=TKo8YdkzGXLi7iLJXr1X7YFmnFyQDpUKHHE7fhjyVPPRt/FIvo8yMH8Q US2LWxMaYEN49Ei3X4K0YGJVHmmJplu5Tkb9wVbLK5VzUOidlOg/pMxww l5tpF5vnIkd1z+HErLvAHJuGdupeCjOz9Inuy16Yj/v40tmX99RT34nrb tc/rVsvn0UNx/OknK/926iGS0yJxGYfmjxcMgj85UtDLjADEUMH+mxhqk 3ecqGTFXkFjDC3awhBxSLQRKUXrXnZiS6/aTlNp1hP83KQei3EVTVBH4u aaNQC39uQJKsJdo3de4BUfqBNjbI3mfjweNtPzC/Pil281vYaAYHWzhju A==; X-CSE-ConnectionGUID: FD2IZUBnTVugDMWxSP1WdQ== X-CSE-MsgGUID: rUxsm3uFQcKy7+go36e+Ag== X-IronPort-AV: E=McAfee;i="6800,10657,11624"; a="83793870" X-IronPort-AV: E=Sophos;i="6.20,228,1758610800"; d="scan'208";a="83793870" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by fmvoesa102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Nov 2025 01:50:34 -0800 X-CSE-ConnectionGUID: k3bAcW1WQUOv2cSMLtq6mQ== X-CSE-MsgGUID: lOBdngQ6Q+yBYr5uci4OVw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.20,228,1758610800"; d="scan'208";a="192148937" Received: from iherna2-mobl4.amr.corp.intel.com (HELO kuha) ([10.124.223.25]) by orviesa010.jf.intel.com with SMTP; 26 Nov 2025 01:50:30 -0800 Received: by kuha (sSMTP sendmail emulation); Wed, 26 Nov 2025 11:50:24 +0200 Date: Wed, 26 Nov 2025 11:50:24 +0200 From: Heikki Krogerus To: Duoming Zhou Cc: linux-usb@vger.kernel.org, gregkh@linuxfoundation.org, mitltlatltl@gmail.com, linux-kernel@vger.kernel.org, sergei.shtylyov@gmail.com, stable@vger.kernel.org Subject: Re: [PATCH v2 2/2] usb: typec: ucsi: fix use-after-free caused by uec->work Message-ID: References: Precedence: bulk X-Mailing-List: stable@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: Tue, Nov 25, 2025 at 06:36:27PM +0800, Duoming Zhou kirjoitti: > The delayed work uec->work is scheduled in gaokun_ucsi_probe() > but never properly canceled in gaokun_ucsi_remove(). This creates > use-after-free scenarios where the ucsi and gaokun_ucsi structure > are freed after ucsi_destroy() completes execution, while the > gaokun_ucsi_register_worker() might be either currently executing > or still pending in the work queue. The already-freed gaokun_ucsi > or ucsi structure may then be accessed. > > Furthermore, the race window is 3 seconds, which is sufficiently > long to make this bug easily reproducible. The following is the > trace captured by KASAN: > > ================================================================== > BUG: KASAN: slab-use-after-free in __run_timers+0x5ec/0x630 > Write of size 8 at addr ffff00000ec28cc8 by task swapper/0/0 > ... > Call trace: > show_stack+0x18/0x24 (C) > dump_stack_lvl+0x78/0x90 > print_report+0x114/0x580 > kasan_report+0xa4/0xf0 > __asan_report_store8_noabort+0x20/0x2c > __run_timers+0x5ec/0x630 > run_timer_softirq+0xe8/0x1cc > handle_softirqs+0x294/0x720 > __do_softirq+0x14/0x20 > ____do_softirq+0x10/0x1c > call_on_irq_stack+0x30/0x48 > do_softirq_own_stack+0x1c/0x28 > __irq_exit_rcu+0x27c/0x364 > irq_exit_rcu+0x10/0x1c > el1_interrupt+0x40/0x60 > el1h_64_irq_handler+0x18/0x24 > el1h_64_irq+0x6c/0x70 > arch_local_irq_enable+0x4/0x8 (P) > do_idle+0x334/0x458 > cpu_startup_entry+0x60/0x70 > rest_init+0x158/0x174 > start_kernel+0x2f8/0x394 > __primary_switched+0x8c/0x94 > > Allocated by task 72 on cpu 0 at 27.510341s: > kasan_save_stack+0x2c/0x54 > kasan_save_track+0x24/0x5c > kasan_save_alloc_info+0x40/0x54 > __kasan_kmalloc+0xa0/0xb8 > __kmalloc_node_track_caller_noprof+0x1c0/0x588 > devm_kmalloc+0x7c/0x1c8 > gaokun_ucsi_probe+0xa0/0x840 auxiliary_bus_probe+0x94/0xf8 > really_probe+0x17c/0x5b8 > __driver_probe_device+0x158/0x2c4 > driver_probe_device+0x10c/0x264 > __device_attach_driver+0x168/0x2d0 > bus_for_each_drv+0x100/0x188 > __device_attach+0x174/0x368 > device_initial_probe+0x14/0x20 > bus_probe_device+0x120/0x150 > device_add+0xb3c/0x10fc > __auxiliary_device_add+0x88/0x130 > ... > > Freed by task 73 on cpu 1 at 28.910627s: > kasan_save_stack+0x2c/0x54 > kasan_save_track+0x24/0x5c > __kasan_save_free_info+0x4c/0x74 > __kasan_slab_free+0x60/0x8c > kfree+0xd4/0x410 > devres_release_all+0x140/0x1f0 > device_unbind_cleanup+0x20/0x190 > device_release_driver_internal+0x344/0x460 > device_release_driver+0x18/0x24 > bus_remove_device+0x198/0x274 > device_del+0x310/0xa84 > ... > > The buggy address belongs to the object at ffff00000ec28c00 > which belongs to the cache kmalloc-512 of size 512 > The buggy address is located 200 bytes inside of > freed 512-byte region > The buggy address belongs to the physical page: > page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4ec28 > head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 > flags: 0x3fffe0000000040(head|node=0|zone=0|lastcpupid=0x1ffff) > page_type: f5(slab) > raw: 03fffe0000000040 ffff000008801c80 dead000000000122 0000000000000000 > raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 > head: 03fffe0000000040 ffff000008801c80 dead000000000122 0000000000000000 > head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 > head: 03fffe0000000002 fffffdffc03b0a01 00000000ffffffff 00000000ffffffff > head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff00000ec28b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff00000ec28c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > >ffff00000ec28c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff00000ec28d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff00000ec28d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ================================================================== > > Add disable_delayed_work_sync() in gaokun_ucsi_remove() to ensure > that uec->work is properly canceled and prevented from executing > after the ucsi and gaokun_ucsi structure have been deallocated. > > Fixes: 00327d7f2c8c ("usb: typec: ucsi: add Huawei Matebook E Go ucsi driver") > Cc: stable@vger.kernel.org > Signed-off-by: Duoming Zhou Reviewed-by: Heikki Krogerus > --- > drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c b/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c > index 8401ab414bd..c5965656bab 100644 > --- a/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c > +++ b/drivers/usb/typec/ucsi/ucsi_huawei_gaokun.c > @@ -503,6 +503,7 @@ static void gaokun_ucsi_remove(struct auxiliary_device *adev) > { > struct gaokun_ucsi *uec = auxiliary_get_drvdata(adev); > > + disable_delayed_work_sync(&uec->work); > gaokun_ec_unregister_notify(uec->ec, &uec->nb); > ucsi_unregister(uec->ucsi); > ucsi_destroy(uec->ucsi); > -- > 2.34.1 -- heikki