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=1794590378; b=u78K+pKiuZT8nMNv00MBiae5NQx5NQULo7MUU/MqpzSLjYfsGd9fttyplHGWDrmklQTp 8oNr2vBmw5CkyeyZSkJmTocsxsX9SyR7ElI8k+seUHmLDiD3fDGOWlQllr3fgaLgPOkBv y2w3Fq2YnOjZ4DecPMAh/gz7nEb0lr/Mrv01ay+J9UBWf+V8bZWnPGHYHei2qc/s2xzAs 902N2QH3jZIneQANE44jYtEyNy0Ns90pD1e9ioykSE2Xx6Kr8n7QwhK0V0W6cqYMH1K6W gH5II4rZBTppKdN6MeQ095EZG7NVkRlkb4QpNk+LE8bMYQiLI/rb719IHwvAAQ+hVzA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794590378; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=OlKRAiEucQJUPMkIpisDR4+oy9f3n0Zr0nK5Y78cry8=; b=RZNfS/A+4pC2iwvXtTcTwg2NLqTjqfbG+ACq292gc6AZ3cldwtHl2NjU8pL7qTZ10Whr FJpryZ9ya2qr4dQZykPnIyuYoE8r4s0+EP/Bnd59hx8ZQ2230WCn2P06B22McV0BbYQvl i/SBhqJO7GjgqL1/i1MKLEZPTZqxQhi+F2L3tTxeV4l2GkxQxnKYLQiefo8CBCiaRzOSg ZsCFjhYNLVu++fvo2+Hbl7jBHt5rJhwZYouXynq7cp9ha2eOJyB0IZ21EiZ+gJbMvzCyJ /cy43/rjSHNfoE0ZukjzdjZNVIc3dHmhu/1TXHy6+TRUbyezOtQZ48VFIojQ3GGmKLw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=fJ8HuCmt; 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 740F8606E649; Fri, 13 Nov 2026 17:19:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=fJ8HuCmt Received: by smtp.kernel.org (Postfix) with ESMTPSA id 015841F000C4; Fri, 13 Nov 2026 17:19:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794590378; bh=OlKRAiEucQJUPMkIpisDR4+oy9f3n0Zr0nK5Y78cry8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fJ8HuCmtvwbeYyeJHHObWlD2QeWowmICgunvfNHEyGrZ7NSE+JYbc30U2VO2JrL8w O7qaBKpgl4FwR209Us4pZ58BBO2W5h7S1gogTGGTLG+bMbz4G3qTDEYRtv3RUXDVHj VxTDkflQmQb8L/7fFuR5jDAHD5YSUL2J5FhnVtnI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jason Wang , Stefan Hajnoczi , Cong Zhang , Jens Axboe , Sasha Levin Subject: [PATCH 6.18 349/686] virtio_blk: use synchronous quiesce in virtblk_freeze_priv() Date: Fri, 13 Nov 2026 10:48:02 -0500 Message-ID: <20261113153832.747244792@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153820.902362109@linuxfoundation.org> References: <20261113153820.902362109@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore 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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ 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 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 e577b02cf4003..84dc751266e9b 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -1588,7 +1588,7 @@ static int virtblk_freeze_priv(struct virtio_device *vdev) /* Ensure no requests in virtqueues before deleting vqs. */ memflags = blk_mq_freeze_queue(q); - blk_mq_quiesce_queue_nowait(q); + blk_mq_quiesce_queue(q); blk_mq_unfreeze_queue(q, memflags); /* Ensure we don't receive any more interrupts */ -- 2.53.0