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Wed, 28 Oct 2026 10:37:57 -0400 X-MC-Unique: QF4qfS1LM5m0tpuRNg4TWg-1 X-Mimecast-MFC-AGG-ID: QF4qfS1LM5m0tpuRNg4TWg_1793198276 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 196681955F7B; Wed, 28 Oct 2026 14:37:56 +0000 (UTC) Received: from onestero-thinkpadp1gen7.tpbc.csb (headnet04.pony-001.prod.iad2.dc.redhat.com [10.2.32.116]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id CD3A319560AB; Wed, 28 Oct 2026 14:37:53 +0000 (UTC) Received: by onestero-thinkpadp1gen7.tpbc.csb (nbSMTP-1.00) for uid 13628 oleg@redhat.com; Wed, 28 Oct 2026 15:37:55 +0100 (CET) Date: Wed, 28 Oct 2026 15:37:52 +0100 From: Oleg Nesterov To: Mani Tofigh via B4 Relay Cc: Andrew Morton , Christian Brauner , linux-mm@kvack.org, linux-kernel@vger.kernel.org, tz2294@columbia.edu, Mani Tofigh Subject: Re: [PATCH] exit: use READ_ONCE() to read mm->owner Message-ID: References: <20261027-kcsan-exit-v1-1-7c0429a29bc0@columbia.edu> X-Archived-By: MIME-Version: 1.0 In-Reply-To: <20261027-kcsan-exit-v1-1-7c0429a29bc0@columbia.edu> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 X-Mimecast-MFC-PROC-ID: 3nwNzYopAPv45V7Jj1GJKP1yYV5jMxrJecL8LdptKa4_1793198276 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Queue-Id: 1A3A4C0005 X-Stat-Signature: pg6ftfhnjq3j8cr89tz7bsopxx16kyti X-Rspamd-Server: rspam04 X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Rspam-User: X-HE-Tag: 1793198283-809623 X-HE-Meta: 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 ynKMELYj euiZfQSPH2BPBsQ23NOfU/k2MAPpFqimr8ljqiZ3L1rmpdDoOc3vt9az1SmY7yLUizhQTYZdKcNAIKQqC9jKeY4RpucQY8gRIOTR4VqxCM4RpBA9LxR8hLgW0W+hZ6RIpkoZg3tS/blU4pzTibmE381KRrGVo+f+dEVC6HCebkZRZtKF1BA8lM6b1d/0KkugixYBbQK1Wq3wY47ajdd3FCTIUYhBw+y3o41NYPRXC1bbQZKO4CHL8HRSdNhOCZAOC1rGB/8pg+MTqnSTgscwVabNruNyVKdBTiXYeLVeLLPsT2wwWto21QCFeN22L01kyBX5GlFT3BPLm3arWEMY72q8DQ7fXJiOwgUMYcsqIcLkGMXkxKJvTMqT7PmfIY4201E+ZE82wmbARmaROj4sR9suiAS3GGl4frW0DQrnpxgGPebPI57xDUhAJvEVC88yKdqnlED98EftUf7GRPRL7/YlT6G6M/zIdId+6v8BXsWWaLDQHbXDJWceeze1H4XzKHvRlpP+3PSL3XleiZF2kd7FvWSGdSyXGO3oAMJEMUHSwdPA= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On 10/27, Mani Tofigh via B4 Relay wrote: > > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -494,7 +494,7 @@ void mm_update_next_owner(struct mm_struct *mm) > * If the exiting or execing task is not the owner, it's > * someone else's problem. > */ > - if (mm->owner != p) > + if (READ_ONCE(mm->owner) != p) Acked-by: Oleg Nesterov