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=1793212535; b=oEIuhDCBzbKqrY6qF5T0wkZLeEjy7gEq+J6onY97CgWaQC6B3YS1ROUC+W9amPP1PSOS LBWGc7hFB+2BhBfDnL+wCLWtc4a3SFqVxx+ydonhe2aJz6JIN1+nbbW5e3s8Bk0tPWLEs KVmbuJjaHX+TIWz5F2vku3SWdEWI+5T5pTllV2eosD3b69N4T5fFUGNMdqLPrDxlCPJSI 5mM4Ee4wqQ+Q+vb8VAJvwIphtV+Gh3r7E3zHA78U+UdxIj9BhINv40qqNCwkOyYhmZXHV lkFLe/0tE0ShK2rdtpHjSiiCsDsl0QP96eCcc+N/6AROD8/7PJZngneSkVJexyGtkhw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793212535; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=Mr9cTvzp2DJzq4e+c1cnIXzYdS0FNBwPXrbs/G1Zbyw=; b=YYM5kI45t/Mb1qgVYKPORTDSAwof2UfjvYP9obL9XcMrq5BkEp9JKhqgQKiOtwln+X2q 64n2eAXPDVZ0p2x7NSwtyiuEI8uwWfOibi8+PBL89VOSnOgIw0c6RLJ01d98fS/SbcvsH eAKVhU2y/Tc+TqJtAj+qZtPM9t/5fcUKHHRDrjA0mzuz1ysWUS/P6WJWGK3XLlkA7+ALZ CP8k2WLPvianJ8PpLTc/shZ1bcoNwfjB5GcAUZDOcnuhaw5AYrSNGtaLdXI2fojhCiYkt p4na8OBtQvZT4WbMU3gd5fBoKRCLFUs5Qa7vHtceM/QGdiGP7KadwTkv8TxAUFSeZPw== 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=YQUxM4B8; 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 358DE606A321 for ; Wed, 28 Oct 2026 18:35:35 +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=YQUxM4B8 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 60F9C1F01828; Wed, 28 Oct 2026 18:35:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793212534; bh=Mr9cTvzp2DJzq4e+c1cnIXzYdS0FNBwPXrbs/G1Zbyw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=YQUxM4B8HQgue7CLME+XiXNG6rHo3ziuePrz5sw/+2A7kU7CUwjNpE3cvuhalVq41 LJK1IzhJcxX5+sYZhhfB4zmjWGzL0AOjR6PGPHl/4tKzPZd1UJW0jI0USz2T/4KKgs R3R0msz3YxKuKrZ+TGOM2CU78v0RjPFPuqKm1C5EVLLaW4jiE1mHaR3Qc85tOg/VeY i8eHczTauFVTxJLJ5Q3/jqwEz6nWnq6WXYRjXrxwBnXmnRNSLQZYuyjP9j0ZEv2EvK dPD66vqTLxV4hN7OR5GzKIEf+qSwb++v7RNs/0zMkXmE6V5LW6AUG9Xg6gfIlMMG8O oyWdkr/DSTVpQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Christian Brauner , Oleg Nesterov , Sasha Levin Subject: [PATCH 6.18.y 1/2] fork: move the coredump and exec checks into create_io_thread() Date: Wed, 28 Oct 2026 14:35:32 -0400 Message-ID: <20261028183505.1719907-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026102850-pulverize-satin-96a4@gregkh> References: <2026102850-pulverize-satin-96a4@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 6734b94600333..bf0bbd8a569e5 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2559,6 +2559,10 @@ 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