Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: BUG: KASAN: use-after-free in enqueue_timer+0x4f/0x1e0
From:   Kim Phillips <kim.phillips@amd.com>
To:     Ainux <ainux.wang@gmail.com>,
        Thomas Zimmermann <tzimmermann@suse.de>
Cc:     airlied@redhat.com, airlied@linux.ie, daniel@ffwll.ch,
        sterlingteng@gmail.com, chenhuacai@kernel.org,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <0f7871be-9ca6-5ae4-3a40-5db9a8fb2365@amd.com>
Message-ID: <a6d2d16c-173f-d49b-ec54-defd6be2bb0c@amd.com>
Date:   Mon, 11 Oct 2021 11:07:14 -0500
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.13.0
In-Reply-To: <0f7871be-9ca6-5ae4-3a40-5db9a8fb2365@amd.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?TnNrcmg0Q3lkbnorSjBGM01PRHB2Q0hxSkU2bUYvWnRwU2NGMnpmLzRDc01y?=
 =?utf-8?B?UVJwRXdpSGhKSGx3Z1lxODFJNks4NEZKcWZGSW1XbkF3bGtJTEc2aWkwMFBm?=
 =?utf-8?B?SFdKLzFXeGxGVUoyTFFxMHR0NmJwWGd0VUVmMStlOStHQUVFSlFpUGFUclBK?=
 =?utf-8?B?RG14NTA2bTAzczBoOFMxc21sWFYzTnhHbVE0blZOSnZSUUNGUWVYUDdnaXQx?=
 =?utf-8?B?YW9MOFBWVVRIbXBLVkwrcFpIRVA4T0xvRDl1c0l2WTErOW1rRGtTVHlJRmJz?=
 =?utf-8?B?Wm1wWXdqcXlOSmFwOXhBRlZLdlBuSUhNVXdDTWZ5MGo1NFV2T1VSYzUwNXU5?=
 =?utf-8?B?alhucTdHYmdWMEFMZmJ2MEZrUDZFOE9FcXdQcUxBMERXVVhZelJiOXNDNVpa?=
 =?utf-8?B?WjM0RXNtNDg4STRFeFJRcDlxcWw0cUI1NGJmZUJLZzhPUWZkbExQZFNUb1NI?=
 =?utf-8?B?YWlzM2g5Zlk5bW5OT09qVXhvQkgvWnFham4wTVJIai82UW9KaDdXa1J6cVc0?=
 =?utf-8?B?Zm9ubnZiaTJ1cENCSm5rMFhCc3Y1eTJOc2ZjTjF3U3pDRnhieTk3UjlZa1p2?=
 =?utf-8?B?NHRjdldhRWF4VE9OUkltWmc0SE8zMkx5aDdwekhScERXcGtkZHBtbmRHb3BN?=
 =?utf-8?B?K1NOOXpFeUk2cU5xc2Z5dlN6Yzl5blFMNmpCdWxTbXVlUytGcnRpeU9kam1i?=
 =?utf-8?B?UWRqMFN5bVRPZG15ZUJvelRrQ2xzQjlXaTJpM1RqMktvc3FDTWVMOVlGYWp0?=
 =?utf-8?B?L1ZEM0FzcERlUU10Qnk3aytQQ01IOE9zZ3ZiS0JUTWJMY2s5R25ZeFNmeUxT?=
 =?utf-8?B?RlZIZmF6RDJLTStsMFhlSmJJNGRYajEwdTdpckVDMXZMTGJlQTFJTFNnSExJ?=
 =?utf-8?B?UDlEZHJUbWZWaHdubW1ldW4vWnViRWZCbDFXK09YMWkwNXN1dkhPcStZcVJ4?=
 =?utf-8?B?SWFIdEVvcXJzWXg3K0d6S1JqTG1vdHlZZGRPZ2NMWkh6U1ArQnZGbUVqYlBo?=
 =?utf-8?B?bS9zZjBWWlIvcXhibmRWQjdCR0tBYlo4OVhnQnJHejI1MVJZNnY0ZXgzc0F0?=
 =?utf-8?B?TXpRejJXMlQvWkZnSm1JWVVUcG5qOExXOW85RlpXRHN0VzhKZHFWTHRESlN0?=
 =?utf-8?B?L0lXdG5MUXdzZTFCcVpqVk1qcWxHUWE3S0gzOFI2R01PWSs5SUwzT1VKSlIy?=
 =?utf-8?B?R2Y4ZkpHdUNkU0F3dEhaOUkxUmNtM1hHQU5FczYvVWRFSTYyS0JZbGd1aTc0?=
 =?utf-8?B?RWdFUDYyaVRXd0dQNmJLOUFDWWxoS2pZazVzOU5YUXBlcWk4U3FrdmZZVEtY?=
 =?utf-8?B?VVJxYzFuZnN4MlFua0NFN3dwL2k3V3dmNW01Mk5FdE5VMldGVTl0UDlJMEJO?=
 =?utf-8?B?QlordGF5ZTlXMWtIdHU2cVZqc08rOWNneC9YbnJOZEhKV081Y0ZYZGlNRkZI?=
 =?utf-8?B?WXN3TmZtS1pyNElkejRMb3JReXdiS3hqWW9ERXZkV1dJL0tCRng5TmJlWmR6?=
 =?utf-8?B?WnRPUmlXcFdQNTdIcWpMSFRGMzlETWl5VnkweVhRRnpBWTFSbDJ3VXhncmRJ?=
 =?utf-8?B?amNveDlVdS9lTkRpdWlDUEVIR0wzMUVVU2o4ZnRvQmVtUk1NVFREcVVGbEVo?=
 =?utf-8?B?WngvY0xKOEh1T3ZFbld4QmhUSWpkS1M5SHhUYmNOU3lhTEZZdlJnc1ZLQ3dC?=
 =?utf-8?B?ZzRGb1RrNDI3Vzg3WVRNOWdUcVRFTVI5aDFTRVZpcDhNNjJaN1RrbFhqNWxn?=
 =?utf-8?Q?c1GQ+O8ETuT4ZBfcmOGLLF1A3MPavYQgv77RRkb?=
X-OriginatorOrg: amd.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 2524fb2f-5292-4759-ccf1-08d98cd131d2
X-MS-Exchange-CrossTenant-AuthSource: BN8PR12MB3505.namprd12.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Oct 2021 16:07:16.3157
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 4UfXGOZQJXiHMS23hsTBtlf/GL3QxVzB/j91oC2wxswE854daT/ho7CUrxSB1zDMhX0qzBT8lHYUnwG3p5rt1w==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN6PR12MB1522
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi,

On 10/5/21 1:10 PM, Kim Phillips wrote:
> Hi, I occasionally see the below trace with Linus' master on an
> AMD Milan system:
> 
> [   25.657322] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [   25.665097] #PF: supervisor instruction fetch in kernel mode
> [   25.671448] #PF: error_code(0x0010) - not-present page
<snip>
> That bisection led to this commit:
> 
> commit aae74ff9caa8de9a45ae2e46068c417817392a26
> Author: Ainux <ainux.wang@gmail.com>
> Date:   Wed May 26 19:15:15 2021 +0800
>      drm/ast: Add detect function support
<snip>
> I confirmed that if I revert it from v5.15-rc4 (after reverting
> its dependent 572994bf18ff "drm/ast: Zero is missing in detect
> function"), the problem goes away.
> 
> Full .config, dmesg attached.
> 
> I can test any possible fixes...


Ping - if no fixes are in the works, can the offending commit(s)
be reverted?

Thanks,

Kim