From: Scott Bauer <sbauer@plzdonthack.me>
To: David Kozub <zub@linux.fjfi.cvut.cz>
Cc: linux-kernel@vger.kernel.org, axboe@kernel.dk, hch@infradead.org,
jonathan.derrick@intel.com
Subject: Re: [PATCH v2 11/16] block: sed-opal: ioctl for writing to shadow mbr
Date: Sat, 19 Jan 2019 12:15:50 -0500 [thread overview]
Message-ID: <20190119171550.GB12171@hacktheplanet> (raw)
In-Reply-To: <1547760716-7304-12-git-send-email-zub@linux.fjfi.cvut.cz>
On Thu, Jan 17, 2019 at 09:31:51PM +0000, David Kozub wrote:
> +static int write_shadow_mbr(struct opal_dev *dev, void *data)
> +{
> + struct opal_shadow_mbr *shadow = data;
> + const u8 __user *src;
> + u8 *dst;
> + size_t off = 0;
> + u64 len;
> + int err = 0;
> +
> + /* do the actual transmission(s) */
> + src = (u8 *) shadow->data;
> + while (off < shadow->size) {
> + err = cmd_start(dev, opaluid[OPAL_MBR], opalmethod[OPAL_SET]);
> + add_token_u8(&err, dev, OPAL_STARTNAME);
> + add_token_u8(&err, dev, OPAL_WHERE);
> + add_token_u64(&err, dev, shadow->offset + off);
> + add_token_u8(&err, dev, OPAL_ENDNAME);
> +
> + add_token_u8(&err, dev, OPAL_STARTNAME);
> + add_token_u8(&err, dev, OPAL_VALUES);
> +
> + /*
> + * The bytestring header is either 1 or 2 bytes, so assume 2.
> + * There also needs to be enough space to accommodate the
> + * trailing OPAL_ENDNAME (1 byte) and tokens added by
> + * cmd_finalize.
> + */
> + len = min(remaining_size(dev) - (2+1+CMD_FINALIZE_BYTES_NEEDED),
> + (size_t)(shadow->size - off));
What if remaining_size(dev) < 2 + 1 + CMD_FINALIZE_BYTES_NEEDED? If that's possible we
get min(UINT_MAX(ish) , some size larger than our remaining buffer) and that's not good.
> + pr_debug("MBR: write bytes %zu+%llu/%llu\n",
> + off, len, shadow->size);
> +
> + dst = add_bytestring_header(&err, dev, len);
> + if (!dst)
> + break;
> + if (copy_from_user(dst, src + off, len))
> + err = -EFAULT;
> --
> 2.20.1
>
>
next prev parent reply other threads:[~2019-01-19 17:16 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-17 21:31 [PATCH v2 00/16] block: sed-opal: support shadow MBR done flag and write David Kozub
2019-01-17 21:31 ` [PATCH v2 01/16] block: sed-opal: fix typos and formatting David Kozub
2019-01-17 21:31 ` [PATCH v2 02/16] block: sed-opal: use correct macro for method length David Kozub
2019-01-17 21:31 ` [PATCH v2 03/16] block: sed-opal: unify space check in add_token_* David Kozub
2019-01-17 21:31 ` [PATCH v2 04/16] block: sed-opal: close parameter list in cmd_finalize David Kozub
2019-01-17 21:31 ` [PATCH v2 05/16] block: sed-opal: unify cmd start David Kozub
2019-01-17 21:31 ` [PATCH v2 06/16] block: sed-opal: unify error handling of responses David Kozub
2019-01-17 21:31 ` [PATCH v2 07/16] block: sed-opal: reuse response_get_token to decrease code duplication David Kozub
2019-01-17 21:31 ` [PATCH v2 08/16] block: sed-opal: print failed function address David Kozub
2019-01-17 21:31 ` [PATCH v2 09/16] block: sed-opal: split generation of bytestring header and content David Kozub
2019-01-17 21:31 ` [PATCH v2 10/16] block: sed-opal: add ioctl for done-mark of shadow mbr David Kozub
2019-01-17 21:31 ` [PATCH v2 11/16] block: sed-opal: ioctl for writing to " David Kozub
2019-01-19 17:15 ` Scott Bauer [this message]
2019-01-20 10:27 ` David Kozub
2019-01-20 21:20 ` Scott Bauer
2019-01-17 21:31 ` [PATCH v2 12/16] block: sed-opal: unify retrieval of table columns David Kozub
2019-01-17 21:31 ` [PATCH v2 13/16] block: sed-opal: check size of shadow mbr David Kozub
2019-01-19 17:29 ` Scott Bauer
2019-01-17 21:31 ` [PATCH v2 14/16] block: sed-opal: pass steps via argument rather than via opal_dev David Kozub
2019-01-17 21:31 ` [PATCH v2 15/16] block: sed-opal: don't repeat opal_discovery0 in each steps array David Kozub
2019-01-19 17:46 ` Scott Bauer
2019-01-20 20:23 ` David Kozub
2019-01-17 21:31 ` [PATCH v2 16/16] block: sed-opal: rename next to execute_steps David Kozub
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=20190119171550.GB12171@hacktheplanet \
--to=sbauer@plzdonthack.me \
--cc=axboe@kernel.dk \
--cc=hch@infradead.org \
--cc=jonathan.derrick@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=zub@linux.fjfi.cvut.cz \
/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).