From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 49DAA279323; Tue, 8 Apr 2025 12:55:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744116902; cv=none; b=YxWYzJLSK/jE4PP5b+0MMVhHsTX1p9ocro0F5Z9HXMFibCemXTeoOjlQoOTXg+oFSHArQkaUMM4NeZmYpLMtqYzlmFjwJbF5x6nInbdHg0w84S/N+gstxBi/RdkAJhSYgHHEnf9tEGFoD+oP1BgfpgiEpon5n+3z7CKx8YbxpCA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744116902; c=relaxed/simple; bh=ZATwbg86x0XOYw3ZJiMOKIUvAz05daeYqVFr8zHG5C4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pjAmzkx3MKt+Y3ruQ2RIJmglqKpQ+FZ8QIFQPRAqmEr3AfoV63acpf5eAE9i2UiUuyEQ7HRnRM7gj68Pzl2f4DKBxtcQeGS0Dv30wN5y+IMSxbrp6B2Zwy3WmNMiHLR5VOapu+P/7rYmoIV4WjZJd04uJEdqUlzduKJwy/53ttM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cgMusYhw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="cgMusYhw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC9CFC4CEEA; Tue, 8 Apr 2025 12:55:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744116902; bh=ZATwbg86x0XOYw3ZJiMOKIUvAz05daeYqVFr8zHG5C4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cgMusYhwJSbWHlAb1qARRuDjgMp/KlqbUtcLy/CBff2r6RClGsF7QVy00KrfXsL4B SqL89Ac9sUHXD5sLKuRpbFvRj62EuoxfQeeMV7Imfz2BgoQ8DHEn4ka7nFnPfxLQIP Cq8cQbfWBO3+qREdiT67URVO8Wc3ypWz0bWGummc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ming Lei , Jens Axboe , Sasha Levin Subject: [PATCH 6.12 312/423] ublk: make sure ubq->canceling is set when queue is frozen Date: Tue, 8 Apr 2025 12:50:38 +0200 Message-ID: <20250408104853.070758963@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250408104845.675475678@linuxfoundation.org> References: <20250408104845.675475678@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ming Lei [ Upstream commit 8741d0737921ec1c03cf59aebf4d01400c2b461a ] Now ublk driver depends on `ubq->canceling` for deciding if the request can be dispatched via uring_cmd & io_uring_cmd_complete_in_task(). Once ubq->canceling is set, the uring_cmd can be done via ublk_cancel_cmd() and io_uring_cmd_done(). So set ubq->canceling when queue is frozen, this way makes sure that the flag can be observed from ublk_queue_rq() reliably, and avoids use-after-free on uring_cmd. Fixes: 216c8f5ef0f2 ("ublk: replace monitor with cancelable uring_cmd") Signed-off-by: Ming Lei Link: https://lore.kernel.org/r/20250327095123.179113-2-ming.lei@redhat.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/ublk_drv.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index c7d728d686e5a..79b7bd8bfd458 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -1416,17 +1416,27 @@ static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) } } +/* Must be called when queue is frozen */ +static bool ublk_mark_queue_canceling(struct ublk_queue *ubq) +{ + bool canceled; + + spin_lock(&ubq->cancel_lock); + canceled = ubq->canceling; + if (!canceled) + ubq->canceling = true; + spin_unlock(&ubq->cancel_lock); + + return canceled; +} + static bool ublk_abort_requests(struct ublk_device *ub, struct ublk_queue *ubq) { + bool was_canceled = ubq->canceling; struct gendisk *disk; - spin_lock(&ubq->cancel_lock); - if (ubq->canceling) { - spin_unlock(&ubq->cancel_lock); + if (was_canceled) return false; - } - ubq->canceling = true; - spin_unlock(&ubq->cancel_lock); spin_lock(&ub->lock); disk = ub->ub_disk; @@ -1438,14 +1448,23 @@ static bool ublk_abort_requests(struct ublk_device *ub, struct ublk_queue *ubq) if (!disk) return false; - /* Now we are serialized with ublk_queue_rq() */ + /* + * Now we are serialized with ublk_queue_rq() + * + * Make sure that ubq->canceling is set when queue is frozen, + * because ublk_queue_rq() has to rely on this flag for avoiding to + * touch completed uring_cmd + */ blk_mq_quiesce_queue(disk->queue); - /* abort queue is for making forward progress */ - ublk_abort_queue(ub, ubq); + was_canceled = ublk_mark_queue_canceling(ubq); + if (!was_canceled) { + /* abort queue is for making forward progress */ + ublk_abort_queue(ub, ubq); + } blk_mq_unquiesce_queue(disk->queue); put_device(disk_to_dev(disk)); - return true; + return !was_canceled; } static void ublk_cancel_cmd(struct ublk_queue *ubq, struct ublk_io *io, -- 2.39.5