From: "Verma, Vishal L" <vishal.l.verma@intel.com>
To: "Zhang, Yu C" <yu.c.zhang@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"yi.z.zhang@linux.intel.com" <yi.z.zhang@linux.intel.com>,
"Williams, Dan J" <dan.j.williams@intel.com>,
"linux-nvdimm@lists.01.org" <linux-nvdimm@lists.01.org>,
"zwisler@kernel.org" <zwisler@kernel.org>,
"Jiang, Dave" <dave.jiang@intel.com>,
"jack@suse.cz" <jack@suse.cz>
Cc: "Zhang, Yi Z" <yi.z.zhang@intel.com>
Subject: Re: [PATCH V2 1/1] device-dax: check for vma range while dax_mmap.
Date: Mon, 20 Aug 2018 17:53:59 +0000 [thread overview]
Message-ID: <1534787638.13739.52.camel@intel.com> (raw)
In-Reply-To: <46441800c43f029757c70d8386e3112701081503.1534160958.git.yi.z.zhang@linux.intel.com>
On Mon, 2018-08-13 at 20:02 +0800, Zhang Yi wrote:
> This patch prevents a user mapping an illegal vma range that is larger
> than a dax device physical resource.
>
> When qemu maps the dax device for virtual nvdimm's backend device, the
> v-nvdimm label area is defined at the end of mapped range. By using an
> illegal size that exceeds the range of the device dax, it will trigger a
> fault with qemu.
>
> Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com>
> ---
> drivers/dax/device.c | 29 +++++++++++++++++++++++++++++
> 1 file changed, 29 insertions(+)
>
Looks good to me:
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
> diff --git a/drivers/dax/device.c b/drivers/dax/device.c
> index 108c37f..6fe8c30 100644
> --- a/drivers/dax/device.c
> +++ b/drivers/dax/device.c
> @@ -177,6 +177,33 @@ static const struct attribute_group *dax_attribute_groups[] = {
> NULL,
> };
>
> +static int check_vma_range(struct dev_dax *dev_dax, struct vm_area_struct *vma,
> + const char *func)
> +{
> + struct device *dev = &dev_dax->dev;
> + struct resource *res;
> + unsigned long size;
> + int ret, i;
> +
> + if (!dax_alive(dev_dax->dax_dev))
> + return -ENXIO;
> +
> + size = vma->vm_end - vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT);
> + ret = -EINVAL;
> + for (i = 0; i < dev_dax->num_resources; i++) {
> + res = &dev_dax->res[i];
> + if (size > resource_size(res)) {
> + dev_info_ratelimited(dev,
> + "%s: %s: fail, vma range overflow\n",
> + current->comm, func);
> + ret = -EINVAL;
> + continue;
> + } else
> + return 0;
> + }
> + return ret;
> +}
> +
> static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
> const char *func)
> {
> @@ -469,6 +496,8 @@ static int dax_mmap(struct file *filp, struct vm_area_struct *vma)
> */
> id = dax_read_lock();
> rc = check_vma(dev_dax, vma, __func__);
> + if (!rc)
> + rc = check_vma_range(dev_dax, vma, __func__);
> dax_read_unlock(id);
> if (rc)
> return rc;
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
next prev parent reply other threads:[~2018-08-20 17:54 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-13 12:02 [PATCH V2 1/1] device-dax: check for vma range while dax_mmap Zhang Yi
2018-08-20 17:53 ` Verma, Vishal L [this message]
2018-08-20 19:50 ` Dave Jiang
2018-08-21 16:16 ` Yi Zhang
2018-12-11 0:10 ` Dan Williams
2018-12-13 6:12 ` Yi Zhang
2018-12-20 1:41 ` Dan Williams
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1534787638.13739.52.camel@intel.com \
--to=vishal.l.verma@intel.com \
--cc=dan.j.williams@intel.com \
--cc=dave.jiang@intel.com \
--cc=jack@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvdimm@lists.01.org \
--cc=yi.z.zhang@intel.com \
--cc=yi.z.zhang@linux.intel.com \
--cc=yu.c.zhang@intel.com \
--cc=zwisler@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).