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=1793216686; b=TkGKrrIxXxX7iAfHDOvtgvG5xCaEYqIzpEPIo5eooe7nXgtdEP/aNkr0OdO9OZFyF08X M4LSR9yiEhgHZ8uM4FUcrbAmqxPg2PFwqk9SQyOfSl1A5DjFkt0t4z3CVPzVC84/amtkB yXqECz/qWdHfh9qL1KbIXrILuDT4H4kew4W2Fmczxg/VsU2OrsM3+GgZkXiTenf7ovkzd ViT9SwBWgnaMoYmufinYU6RZIU6jQkoagjqKVZnqsab/AiaSeW2aHcfR1eKVS4nf6XbCg Bp1DC9791tozWTomqzKV3R3MHsg+inWdtVMleMsZX9ei8TuKmwAAnAui7irX/fXr5RQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793216686; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=aX5yxWLy5UqgCew+TXik/kA3SFLV0ENzFXkHOTx9H70=; b=NHNT+HNHQPLcyEpHm2HqaYUKMD76bmY0v07uqCgm4UHC0yQeV8VCq8vSnr1ggYC0Sklr f/8RgPpQc+uPFSBXC6SsozC3Cb6ORi3tZkThOA3nIaAgbkKmf3Pdwo7WOX9RLFYvYMCNx bEhIDGLpwmxYsG0Micfl2Qv/qPpYWShg8lwlGQoGJIPN2xVVxB42S7IkrkSuOADkBPJHV jUtv8m8g5g+rHbrHovJYTXaj/vxjipenbwio+uo58t7uZsjf+w2IZQRFh/DlWp4jnT01B r1qVGCIKGYUju1ampXI77hqTH8+xAUr5ehPR/af0OXKuCgOy+29a/GXIklQ4zYyuqqQ== 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=LVUEWX7a; 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 92DCB606A31A for ; Wed, 28 Oct 2026 19:44:46 +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=LVUEWX7a Received: by smtp.kernel.org (Postfix) with ESMTPSA id D936F1F01828; Wed, 28 Oct 2026 19:44:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793216686; bh=aX5yxWLy5UqgCew+TXik/kA3SFLV0ENzFXkHOTx9H70=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LVUEWX7amI3s3lnD2zPsOFJWFNoXV0QdbYjp31DHY3wYnYpwg2bJy7kZyqozRvDAy nADJjSLwByA7lmP0QAX2tgQL04ZVc07sDu9jWALaEKrwxkyT552TGjX6Df6435uwD8 3feNgNYUkjb0MTSqEKai4dgkc//Pmf2GIDt5ehtwxGt6T1T0C5Y+yNWEFtU5V9+uuY K3yCaYZAYVDtcLQSl+cxqQIkPc9FPvlKe7N8PxhzkvJiX/qT9DVpTduSeIotameIOi i3PN8Bb+n7Zorb8SWXOevJxQiBmn45FiKKH26NOeLW5qWPrdvZb3q1v87x1jR0TREy E2hg12lQs3nGA== From: Sasha Levin To: stable@vger.kernel.org Cc: Christian Brauner , Oleg Nesterov , Sasha Levin Subject: [PATCH 6.6.y 1/2] fork: move the coredump and exec checks into create_io_thread() Date: Wed, 28 Oct 2026 15:44:43 -0400 Message-ID: <20261028194315.2086603-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026102851-facelift-wand-29b0@gregkh> References: <2026102851-facelift-wand-29b0@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 396a1d4b05e59..802bccf2dea74 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2867,6 +2867,10 @@ 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