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=1794605582; b=LT9BNTQg8vkM9tgR5/yGxRK3eXAso1dp8p1zxfsJDRibHjdbfUKdyOh70rQN8AgUHDv9 oZsiviX/4mPrkZ4b7fFQbjNIQ565LWg7lqLfv1hyKD9qsXhPwom2XesVA44yEuGdzl9ao 7+E7fJ1uzZxx/WyLkWYGh/kewOZGdFfDpvMt1nJ2CrlukhLJD6cBvzcajFClVLNC3ADdD aaghV3hJ7FgdQMV/dqekHluMshAkp0vsX/ww4gFVPN9qB/6VLtV9VwRTBvL1DKh0yGzI+ j5/rkUd6ghCLoDy+ayHKBrZ+OYlIZOa3WmUdMPTawkgVY5mw+CT++bQRERyV37qC2Mw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794605582; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=iVa0OCDkk47VLOPt6GYeJX1uOGTkrKCBW9S2qUV7nro=; b=HB9UqL5FpzCNb2Fc10nj5xhAhIWk3aw1m20frMkqoATBOkEKCUuFQcW+SmgfWZJUOBr9 oXcbOiHoUX/8QlFQN0ldBnVxRzlYOLhwU20TtjCgOxWG7a/Fy44qAisj0tK2Fjuut21Yz myKwgx3u09RjJRN8uzJuOd34wkQj8Iu7a2/53bNv27yXaLjMXrYAVWOO6B3ZK8oOthWWD OHmIytkSBq5L6Y1VENk+VVJvoBDX3XbVZkEhg3Dt3ESyrirsn+mX3YdaJ4tBHNrwMdDo6 qX8fCA28aM3f9VNVinRY3gWZFz2kUTA9ouMzKtmSpbxZphMIyM1HOeU48lrywXgEo/A== 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=PPkJ6RtE; 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 97423606A880 for ; Fri, 13 Nov 2026 21:33:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=PPkJ6RtE Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77B081F000C4; Fri, 13 Nov 2026 21:33:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794605582; bh=iVa0OCDkk47VLOPt6GYeJX1uOGTkrKCBW9S2qUV7nro=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PPkJ6RtE/gfqC0i8g/momgzCmUH59XRiIjBLVCMdqfnKSgS3DfhCickuRRkyTFSf+ ilABS7NYsArGylIF6GmNmZI6q1bs3D1TgsCobiZI7W/7GEIz9W6tpNaPC/DUQ3U59r wMr4D/6WI+ac0qIanOZG4XSh634absvf5vFt0dNl6/u6w7Iqq9ixfo3SbhIJJQlA8F snyfzE3/2vi9UES11ZLbaKVLsnvvKr9Kd7VlLW4YC1YKKqAx+42X8Q9+VUBHkUrIv3 GKezWijEt/vcx6/knaUJPRasaDo0MnY4U9wo3wBd0A0g8hjBldifQ1l9x6xi5r+340 GVoeC0XizChXA== From: Sasha Levin To: stable@vger.kernel.org Cc: Cong Zhang , Jason Wang , Stefan Hajnoczi , Jens Axboe , Sasha Levin Subject: [PATCH 6.12.y] virtio_blk: use synchronous quiesce in virtblk_freeze_priv() Date: Fri, 13 Nov 2026 16:33:00 -0500 Message-ID: <20261113213243.2680554-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261109200833-failed-6.12-6c6dec7883f8@kernel.org> References: <20261109200833-failed-6.12-6c6dec7883f8@kernel.org> 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: Cong Zhang [ Upstream commit 6c6dec7883f8eb10b326bc9d109a4990c885d949 ] blk_mq_run_work_fn() can call blk_mq_sched_dispatch_requests() through blk_mq_run_dispatch_ops(). The dispatcher checks QUEUE_FLAG_QUIESCED while the flag is clear. It can then be preempted before it gets a request. At that time, it has no queue usage reference, so blk_mq_freeze_queue() does not wait for it. virtblk_freeze_priv() then calls blk_mq_quiesce_queue_nowait() and blk_mq_unfreeze_queue(). A new request can enter the queue. The old dispatcher can run again, use its old flag check, get the new request, and call virtio_queue_rq(). At the same time, virtblk_freeze_priv() can reset the device, delete the virtqueues, and free vblk->vqs. The old dispatcher can then use a deleted virtqueue or a NULL vblk->vqs, and the kernel can crash. Fix this by using blk_mq_quiesce_queue(), which waits for dispatch code that was already running. Keep the existing freeze and unfreeze order. The queue remains quiesced until virtblk_restore_priv() calls blk_mq_unquiesce_queue(). Fixes: 7678abee0867 ("virtio-blk: don't keep queue frozen during system suspend") Cc: stable@vger.kernel.org Acked-by: Jason Wang Reviewed-by: Stefan Hajnoczi Signed-off-by: Cong Zhang Link: https://lore.kernel.org/20260911-virtblk_sync_quiesce-v1-1-a883f8f31258@oss.qualcomm.com Link: https://patch.msgid.link/20261103-virtblk_sync_quiesce-v3-1-f40233f9bdd9@oss.qualcomm.com Signed-off-by: Jens Axboe [ sashal: Adjusted context from virtblk_freeze_priv() to virtblk_freeze() with older freeze/unfreeze signatures lacking memflags. ] Signed-off-by: Sasha Levin --- drivers/block/virtio_blk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 789890f3c5ff4..43884773dc3a8 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -1590,7 +1590,7 @@ static int virtblk_freeze(struct virtio_device *vdev) /* Ensure no requests in virtqueues before deleting vqs. */ blk_mq_freeze_queue(q); - blk_mq_quiesce_queue_nowait(q); + blk_mq_quiesce_queue(q); blk_mq_unfreeze_queue(q); /* Ensure we don't receive any more interrupts */ -- 2.53.0