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 99BC6257C for ; Thu, 23 Feb 2023 13:07:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C428C433D2; Thu, 23 Feb 2023 13:07:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1677157670; bh=o/MvSD7XTSLEAyXjpthVv1oakAMjdRqXebAZP8Tyla4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aP6noMneSofe1MU0q+f4FM1DrQmX7gLu76dGbJh6WwYaxshKrSz5dseKTBekSKP9j lD0/zbL71LYYxFZvK8EH2CKzc7tWDNO19Ed2wpJy0Iw+/6UqXDxm3Hm5qYhTx3OPau Au+eOb7X8bHwD5yZd0UiVLb+mX2cVQr1hRqrAofk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yu Kuai , Josef Bacik , Jens Axboe , Wen Yang Subject: [PATCH 5.10 20/25] nbd: fix possible overflow for first_minor in nbd_dev_add() Date: Thu, 23 Feb 2023 14:06:37 +0100 Message-Id: <20230223130427.691761800@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230223130426.817998725@linuxfoundation.org> References: <20230223130426.817998725@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Yu Kuai commit 940c264984fd1457918393c49674f6b39ee16506 upstream. If 'part_shift' is not zero, then 'index << part_shift' might overflow to a value that is not greater than '0xfffff', then sysfs might complains about duplicate creation. Fixes: b0d9111a2d53 ("nbd: use an idr to keep track of nbd devices") Signed-off-by: Yu Kuai Reviewed-by: Josef Bacik Link: https://lore.kernel.org/r/20211102015237.2309763-3-yebin10@huawei.com Signed-off-by: Jens Axboe Signed-off-by: Wen Yang Signed-off-by: Greg Kroah-Hartman --- drivers/block/nbd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1773,11 +1773,11 @@ static int nbd_dev_add(int index) disk->major = NBD_MAJOR; /* Too big first_minor can cause duplicate creation of - * sysfs files/links, since MKDEV() expect that the max bits of - * first_minor is 20. + * sysfs files/links, since index << part_shift might overflow, or + * MKDEV() expect that the max bits of first_minor is 20. */ disk->first_minor = index << part_shift; - if (disk->first_minor > MINORMASK) { + if (disk->first_minor < index || disk->first_minor > MINORMASK) { err = -EINVAL; goto out_free_idr; }