From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793206534; b=Tk4MhM02xIIQ7zsywK8GDyX90pMIh/773FZ78DF1fHn1mrD+dZSjggC/c93YleNpcWBX aGVemwEMJTKXdq5wkO1Nk8PzxPtQrogeaTWaAP9CgUUXctx3xKa8G9yt/ELseicm1052y oW4FH08Jj3xtUZ4FF6gVy+I5qL6r/d6nBMu9GIyHb2WkDF+dcr57w74eez3ftCtrYaANA UcO1mTQEx0llh+2Lm1KzUp6cKa8Myr2AhDPbNwKZ1ncNlrqTH0iw0l9GuEdZAfapDolAp 0jkUCecTB+0N7LytEAtN0mGfiOqpEG1MxvweHMrGae5zmL0SkNs5Nw+Y8zLFONvO1sA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793206534; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=NDWV14Iz1ezoCOyuU8ksgBsld4EXtOYOznVZ6NftGGQ=; b=ET4vqohtZBrXhjqZVhE1Exl6U8cb+N9JdMWQ2W6atHVI05N1NpsV9ln/UzZNwcFmZECB PGvF2k71gXM+aMg4IlrpwDlYigxO7/aZzpSafswViKVj4kD66UqMTkhbPgRmUjR8gXDRc 6oPJXmusBpZk/6p4MEQaW0NCcgL635fGNMoGwzOG5FI+HwWIEY8t+OA+ehLnOe4+MN1pH nUeXh74/42u8vv1zjb8dm72HuzzmSMHaD2zczggqG8TzwGioFi3XausArlmfJEhhwj1Kz xwcTPcxGrrx+Xky16FL5ywEnZbhLkB2nMul5JjbuztOGOyGKT0fLNfXf8814bFmHrsQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GsLLLnVJ; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BC2F2606A31A for ; Wed, 28 Oct 2026 16:55:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=GsLLLnVJ Received: by smtp.kernel.org (Postfix) with ESMTPSA id D00D51F01825; Wed, 28 Oct 2026 16:55:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793206533; bh=NDWV14Iz1ezoCOyuU8ksgBsld4EXtOYOznVZ6NftGGQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=GsLLLnVJsMHX7h3DThmjLOGc0yJy6DaD7EKfrIwdhaVvAcF6GZgUajsG02hVBtmwP pyOgKIfhYN8tc4ZrNrzEZ1UFzgrP8jV6rS8t4x2UfaeAlqDhvYe9iSwDZzIoqV0mYn jylmYDctshUvNOG6JCB/4yCxx6BGfH6utPed7nM6swKv9fhNTnu75UppQ9/sKKrcBk 0FN1DNbeUV7xhSZex0Xrbl+v//9UDEVg6yYw3ODU2j4N/3c1ewx5nBAocQncrHYC+x KeE+6HyDyKbU7JLQelTScNx9aLuDLYrEFGqwvIDJxjqGgCaX2+6QCD01yVxshJdmAI F3p8u9sTnH1EQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Christian Brauner , Oleg Nesterov , Sasha Levin Subject: [PATCH 7.3.y 1/2] fork: move the coredump and exec checks into create_io_thread() Date: Wed, 28 Oct 2026 12:55:30 -0400 Message-ID: <20261028165506.1601934-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026102848-foster-escapade-ec01@gregkh> References: <2026102848-foster-escapade-ec01@gregkh> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Christian Brauner [ Upstream commit e760200370e4de054b6b5f568a7faa911e2956bb ] Only a PF_USER_WORKER thread returns from get_signal() after a fatal signal and can go on to create a thread. get_signal() sets PF_SIGNALED before it dumps core and before it lets a PF_USER_WORKER thread return. That flags sticks. The exec'ing thread itself is never signaled. But it doesn't need the check anyway as we moved cancellation of io_uring requests before de_thread(). create_io_thread() is the only way a signaled thread creates another one. vhost_task_create() is reached from ioctls alone. io_should_retry_thread() doesn't retry -EINTR, so io-wq callers give up the same way they did when copy_process() refused. Suggested-by: Oleg Nesterov Link: https://lore.kernel.org/r/aq0VLTyxNatFmLOK@redhat.com Link: https://patch.msgid.link/20260921-work-coredump-fixes-v3-13-8e4adb1619e6@kernel.org Acked-by: Oleg Nesterov Signed-off-by: Christian Brauner (Amutable) Stable-dep-of: 1f978881ce6c ("fork: don't create io threads once PF_POSTCOREDUMP is set") Signed-off-by: Sasha Levin --- kernel/fork.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/fork.c b/kernel/fork.c index efe6157fedb43..140b41702c8fe 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2718,6 +2718,10 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node) .user_worker = 1, }; + /* A creator past its fatal signal gets no thread. */ + if (current->flags & PF_SIGNALED) + return ERR_PTR(-EINTR); + return copy_process(NULL, 0, node, &args); } -- 2.53.0