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=1793214216; b=qwyUucmKMjwmXl/yGwpp17uAl9UHhEW1JfiGG2cCx1JCCBB70HdmdXJFGrSs8k0KFo2t yVY0EmlhDGW14MjUz4P0RjA7nCqPaIpqH0A8cd7puSYITXsprVkMxx30LC4s7rr9Afw8j TXc14KDAIJopGBgzbKLGYQfVtA2o7EiwFlkxYTEzahK+9h+ctWa5O+K0e0kP1LgNvJb9Y h41zyCIErppuRY2fVGYnzMkeIMWSGSZJsD6OzrWuAiCUM+9GTtIlltb0fKoVXhfqPmz1z i1a9M9kRPJ/7hsFgGpuJq/PrGnCgPaZx/DtjxcHqhMMXM6Ywangq0Efx1gETHQPmSXg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793214216; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=ItA+kX+KJYP4yRXuma4vjqeyf4jPzGo780LPkrPyJFw=; b=Ov6+5pd3o4nty2BMql7hy9Y06K9YBI5olxaVopjr0dJU+QElWcpEciQ5s+ZWuO9kTWZW dZ4YEEDxtgsXzgT6C18bQXQ5uZWXC2Yldpymbap5nZvfExn7RDS5vUXM9/z0srCmcRowH l5flHqDt5/dCqJcbs9F7i9V81TE7ZhmLho1mxYAW9vMuldTDASkDBJ4fEi/h3YBfB8uW2 rE/4S+p1vO9ZO0+uy56BYQwudnOJJWJR4/20/Pgq6IgiRLh4byZg1lwBETNYs8LOnjU7h yc4mKPZRkSRHYm1e7KbLpTF7ACpVgvEsElmXZrWiL+ICNISINzIMJyVtpXbyp+kG5QA== 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=jfjBRBfD; 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 6A4EE60A2616 for ; Wed, 28 Oct 2026 19:03:36 +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=jfjBRBfD Received: by smtp.kernel.org (Postfix) with ESMTPSA id B60AA1F013C1; Wed, 28 Oct 2026 19:03:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793214216; bh=ItA+kX+KJYP4yRXuma4vjqeyf4jPzGo780LPkrPyJFw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jfjBRBfD5EFfijxw/EnPry7KUwi6zzOwmiQr+H1wezRnx8YB22SPYDZLZN/aoqkVr XmWA6hocZOY//1nv4HSQ50uhcTUwJerdhowfZ5ArYXQAETNieZMRnSZ1uCACvJgphv OPnJHrdNi1bjXoKSs/PntEp3DWBTmrCgckU9deIq7/672ajv5dYVu/NZydp8kZxNhw C7d8PZ5Fc+exQdosWTuBw+sz/ulVrsBQNuUt3HkQQ3CMt0uYwzNnw/Oq5gMhbzUuOA vZWK+jczTwoFAW7XLPCY5g6fNp76K3HT80cBazTMEj6ggreMYl8uMxzNnLtWvSoafI NRs8AIv4r3cLg== From: Sasha Levin To: stable@vger.kernel.org Cc: Christian Brauner , Oleg Nesterov , Sasha Levin Subject: [PATCH 6.12.y 1/2] fork: move the coredump and exec checks into create_io_thread() Date: Wed, 28 Oct 2026 15:03:33 -0400 Message-ID: <20261028190310.2073874-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026102850-unleveled-version-e04b@gregkh> References: <2026102850-unleveled-version-e04b@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 f22b79d9954a8..c82956f8fc9d5 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2774,6 +2774,10 @@ 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