From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E316F26158C for ; Tue, 8 Apr 2025 07:25:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744097109; cv=none; b=AE5TUifr5H4XlAcLozxkTiy2iCLDlsYR+VtbkePa6AsBqa+6AjcOceJRW4FMrlLuSd0NnQpoLJktzv0aj1Ze1JXzxRYVyHZohelT4lyaQ6u6L02PF66s/nttPPG3ExGuZE9NXLA0OxNRmkGM/cn3yZbTyipF7bubWn2QoXsQBdk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744097109; c=relaxed/simple; bh=NkvJUa67NuQAEBMSbkixgf7v1SPBOdLzrFCRTywBiCE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YC36VaxgqI90GFV4Nl8lnsGD+je80v/rXZYbY1xojuQ2qdvuHSz6jdS1WDXRhHoKCfcZBh1FyNW1eZP56ng0X4xoPPSkS9dGdLHtypQTsoEMsHkiCNpqGc7VI5bf2U0MrKZq/QgiBbEfH216Z6gFg0CIrQeSa3eve8uD0splXO0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Df0dw2BW; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Df0dw2BW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744097106; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=cr9eb9fwiL6iLk0VnR2hA8cQwLKNTaPAlkafeN70d14=; b=Df0dw2BWny170H88Wc0sFwdjhi420/fOPCDgV2XH6ipy/wketRI+teDGC3PaUvK3wO00kp KhNUTnvBTM0suVzjzVQLRfvKPeaPiBkXK+zhKXxc5liBv/v0NQrVAI+Zklpt8VqhmE6iOY mBtNbyJz1J96GlDz2w8qWlx38GjihyE= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-629-rUXMot6xN-S9E7fFvPu08A-1; Tue, 08 Apr 2025 03:25:03 -0400 X-MC-Unique: rUXMot6xN-S9E7fFvPu08A-1 X-Mimecast-MFC-AGG-ID: rUXMot6xN-S9E7fFvPu08A_1744097102 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6ED551956048; Tue, 8 Apr 2025 07:25:02 +0000 (UTC) Received: from localhost (unknown [10.72.120.6]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 579A2180176C; Tue, 8 Apr 2025 07:25:00 +0000 (UTC) From: Ming Lei To: Jens Axboe , linux-block@vger.kernel.org Cc: Caleb Sander Mateos , Uday Shankar , Ming Lei Subject: [PATCH 1/2] ublk: fix handling recovery & reissue in ublk_abort_queue() Date: Tue, 8 Apr 2025 15:24:37 +0800 Message-ID: <20250408072440.1977943-2-ming.lei@redhat.com> In-Reply-To: <20250408072440.1977943-1-ming.lei@redhat.com> References: <20250408072440.1977943-1-ming.lei@redhat.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Commit 8284066946e6 ("ublk: grab request reference when the request is handled by userspace") doesn't grab request reference in case of recovery reissue. Then the request can be requeued & re-dispatch & failed when canceling uring command. If it is one zc request, the request can be freed before io_uring returns the zc buffer back, then cause kernel panic: [ 126.773061] BUG: kernel NULL pointer dereference, address: 00000000000000c8 [ 126.773657] #PF: supervisor read access in kernel mode [ 126.774052] #PF: error_code(0x0000) - not-present page [ 126.774455] PGD 0 P4D 0 [ 126.774698] Oops: Oops: 0000 [#1] SMP NOPTI [ 126.775034] CPU: 13 UID: 0 PID: 1612 Comm: kworker/u64:55 Not tainted 6.14.0_blk+ #182 PREEMPT(full) [ 126.775676] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 [ 126.776275] Workqueue: iou_exit io_ring_exit_work [ 126.776651] RIP: 0010:ublk_io_release+0x14/0x130 [ublk_drv] Fixes it by always grabbing request reference for aborting the request. Reported-by: Caleb Sander Mateos Closes: https://lore.kernel.org/linux-block/CADUfDZodKfOGUeWrnAxcZiLT+puaZX8jDHoj_sfHZCOZwhzz6A@mail.gmail.com/ Fixes: 8284066946e6 ("ublk: grab request reference when the request is handled by userspace") Signed-off-by: Ming Lei --- drivers/block/ublk_drv.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 2fd05c1bd30b..41bed67508f2 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -1140,6 +1140,25 @@ static void ublk_complete_rq(struct kref *ref) __ublk_complete_rq(req); } +static void ublk_do_fail_rq(struct request *req) +{ + struct ublk_queue *ubq = req->mq_hctx->driver_data; + + if (ublk_nosrv_should_reissue_outstanding(ubq->dev)) + blk_mq_requeue_request(req, false); + else + __ublk_complete_rq(req); +} + +static void ublk_fail_rq_fn(struct kref *ref) +{ + struct ublk_rq_data *data = container_of(ref, struct ublk_rq_data, + ref); + struct request *req = blk_mq_rq_from_pdu(data); + + ublk_do_fail_rq(req); +} + /* * Since ublk_rq_task_work_cb always fails requests immediately during * exiting, __ublk_fail_req() is only called from abort context during @@ -1153,10 +1172,13 @@ static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io, { WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); - if (ublk_nosrv_should_reissue_outstanding(ubq->dev)) - blk_mq_requeue_request(req, false); - else - ublk_put_req_ref(ubq, req); + if (ublk_need_req_ref(ubq)) { + struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); + + kref_put(&data->ref, ublk_fail_rq_fn); + } else { + ublk_do_fail_rq(req); + } } static void ubq_complete_io_cmd(struct ublk_io *io, int res, -- 2.47.0