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Tue, 17 Mar 2026 08:48:56 -0400 X-MC-Unique: _pS-Wp-TNG2ZhKLZBOo5-A-1 X-Mimecast-MFC-AGG-ID: _pS-Wp-TNG2ZhKLZBOo5-A_1773751733 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-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id B384518005B8; Tue, 17 Mar 2026 12:48:52 +0000 (UTC) Received: from fedora (unknown [10.45.225.204]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id F1E641955F19; Tue, 17 Mar 2026 12:48:43 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Tue, 17 Mar 2026 13:48:52 +0100 (CET) Date: Tue, 17 Mar 2026 13:48:42 +0100 From: Oleg Nesterov To: Deepanshu Kartikey Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kees@kernel.org, akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, brauner@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzbot+bbe6b99feefc3a0842de@syzkaller.appspotmail.com Subject: Re: [PATCH v3] kernel/fork: validate exit_signal in kernel_clone() Message-ID: References: <20260316151956.563558-1-kartikey406@gmail.com> MIME-Version: 1.0 In-Reply-To: <20260316151956.563558-1-kartikey406@gmail.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 X-Mimecast-MFC-PROC-ID: B9HxkiL1ZpmfNb8jxIZvHEW9XXm0b1DU3cf99uiuTZc_1773751733 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Queue-Id: E6CF8180007 X-Rspamd-Server: rspam07 X-Stat-Signature: 4w7e7zquejx3pefyw3p4cajo8ynth5m1 X-Rspam-User: X-HE-Tag: 1773751741-749124 X-HE-Meta: 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 29mehDlL 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 03/16, Deepanshu Kartikey wrote: > > Note that this is a user-visible change: previously, passing an invalid > exit_signal to clone() was silently accepted. The man page for clone() > does not document any defined behavior for invalid exit_signal values, > so rejecting them with -EINVAL is the correct behavior. It is unlikely > that any sane application relies on passing an invalid exit_signal. Agreed... > - if (unlikely((args.exit_signal & ~((u64)CSIGNAL)) || > - !valid_signal(args.exit_signal))) > + if (unlikely(args.exit_signal & ~((u64)CSIGNAL))) > return -EINVAL; I guess this can die too, but OK, this needs another patch/changelog. Acked-by: Oleg Nesterov Andrew, I will slightly update the changelog and resend do_notify_parent-sanitize-the-valid_signal-checks.patch in reply to this patch from Deepanshu. Oleg.