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 20EDA3A8F2 for ; Wed, 15 Nov 2023 19:51:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="PU0LR6yG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A928AC433C8; Wed, 15 Nov 2023 19:51:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700077893; bh=ui37yxyoDcdRB3Ayj/BhQZ/aq48em5voKUmfKvx0kIE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PU0LR6yGvwbJruNJfy9VcH1PsVcX3X4sgGKsWDev9yU2HC4UTZgE+eTeUVVVX+Fhp hi9Dy1Lp744SG83Q/TD2nxEbfpSH9uRv2RJ6e0bEyccLsewBwqCTqVh96A9lmjxo19 xIoMfjMUFwUvHCifxOzqH9Cz6rHi8Qn+jbehBIfg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Li Lingfeng , Josef Bacik , Jens Axboe , Sasha Levin Subject: [PATCH 6.6 567/603] nbd: fix uaf in nbd_open Date: Wed, 15 Nov 2023 14:18:32 -0500 Message-ID: <20231115191650.796497859@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115191613.097702445@linuxfoundation.org> References: <20231115191613.097702445@linuxfoundation.org> User-Agent: quilt/0.67 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Lingfeng [ Upstream commit 327462725b0f759f093788dfbcb2f1fd132f956b ] Commit 4af5f2e03013 ("nbd: use blk_mq_alloc_disk and blk_cleanup_disk") cleans up disk by blk_cleanup_disk() and it won't set disk->private_data as NULL as before. UAF may be triggered in nbd_open() if someone tries to open nbd device right after nbd_put() since nbd has been free in nbd_dev_remove(). Fix this by implementing ->free_disk and free private data in it. Fixes: 4af5f2e03013 ("nbd: use blk_mq_alloc_disk and blk_cleanup_disk") Signed-off-by: Li Lingfeng Reviewed-by: Josef Bacik Link: https://lore.kernel.org/r/20231107103435.2074904-1-lilingfeng@huaweicloud.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/nbd.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 800f131222fc8..855fdf5c3b4ea 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -250,7 +250,6 @@ static void nbd_dev_remove(struct nbd_device *nbd) struct gendisk *disk = nbd->disk; del_gendisk(disk); - put_disk(disk); blk_mq_free_tag_set(&nbd->tag_set); /* @@ -261,7 +260,7 @@ static void nbd_dev_remove(struct nbd_device *nbd) idr_remove(&nbd_index_idr, nbd->index); mutex_unlock(&nbd_index_mutex); destroy_workqueue(nbd->recv_workq); - kfree(nbd); + put_disk(disk); } static void nbd_dev_remove_work(struct work_struct *work) @@ -1608,6 +1607,13 @@ static void nbd_release(struct gendisk *disk) nbd_put(nbd); } +static void nbd_free_disk(struct gendisk *disk) +{ + struct nbd_device *nbd = disk->private_data; + + kfree(nbd); +} + static const struct block_device_operations nbd_fops = { .owner = THIS_MODULE, @@ -1615,6 +1621,7 @@ static const struct block_device_operations nbd_fops = .release = nbd_release, .ioctl = nbd_ioctl, .compat_ioctl = nbd_ioctl, + .free_disk = nbd_free_disk, }; #if IS_ENABLED(CONFIG_DEBUG_FS) -- 2.42.0