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Mon, 24 Mar 2025 14:38:27 -0400 X-MC-Unique: So49VpcsPLSk5FJJVtoabw-1 X-Mimecast-MFC-AGG-ID: So49VpcsPLSk5FJJVtoabw_1742841506 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (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-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7D9E218EBE99; Mon, 24 Mar 2025 18:38:25 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.224.42]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 906A6180A801; Mon, 24 Mar 2025 18:38:21 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Mon, 24 Mar 2025 19:37:52 +0100 (CET) Date: Mon, 24 Mar 2025 19:37:47 +0100 From: Oleg Nesterov To: Mateusz Guzik Cc: syzbot , brauner@kernel.org, kees@kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com Subject: Re: [PATCH] exec: fix the racy usage of fs_struct->in_exec Message-ID: <20250324183746.GB29185@redhat.com> References: <67dc67f0.050a0220.25ae54.001f.GAE@google.com> <20250324160003.GA8878@redhat.com> <20250324182722.GA29185@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250324182722.GA29185@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 X-Rspamd-Server: rspam01 X-Stat-Signature: t7negjjxp9tafuuy3t5i6ugrs9tb71q7 X-Rspam-User: X-Rspamd-Queue-Id: B28ECC0014 X-HE-Tag: 1742841511-841961 X-HE-Meta: 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 cBORHdgV T34GRBv64PvGuEU7Lu5fWLo0M3ekkMEJ0UIm5XsWR+U1egzzH7505Qf+4REoTpSUljZJwfwfOyqSsoRtofQQeYm88RUumamOaHvvWjcrgr6WaZzlhXHrKayzDKCpCqMc9v5UKx5Frh694hk53Y3xEyVDZgZu90Jz1bIzeQXhqQUwtcAdcGGBoLucjwu5zqNcdZWVvUSbwCm1Hli5WnErr39vsZe36xq9Rc47SIeAqZcSneASWT/FslqMouUOZDNxa6CEx/HNvkWGY8uX6xFiaWPNyuIp7C1sr3BYT/nqJHyYcsmc0ZFE4D63M2dcU/nSEqxk9gkz8jv+qZySdGwv4/bPsdRMnF7As6WYYVcp20HwuAb8NxGEADJ8WBz27Wbo5zmxb665aeoq7ZOMY4YyPTAkRtgw8eds96t/1ZLcWtUjmNzU9vpZLGdRU+QFN3PWfushHahSgz6t1hVEo6TruaFf+Zw== X-Bogosity: Ham, tests=bogofilter, spamicity=0.035926, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 03/24, Oleg Nesterov wrote: > > I won't argue with another solution. But this problem is quite old, Yes, but... > unless I am totally confused this logic was wrong from the very > beginning when fs->in_exec was introduced by 498052bba55ec. OK, I was wrong. According to git show 498052bba55ec:fs/exec.c this patch was correct in this respect. Sorry for the noise. > So to me it would be better to have the trivial fix for stable, > exactly because it is trivially backportable. Then cleanup/simplify > this logic on top of it. Yes... Oleg.