All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Pavel Machek <pavel@ucw.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-kernel@vger.kernel.org, stable@vger.kernel.org,
	Marc Kleine-Budde <mkl@pengutronix.de>,
	Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 4.4 24/28] can: dev: prevent potential information leak in can_fill_info()
Date: Tue, 2 Feb 2021 22:51:01 +0300	[thread overview]
Message-ID: <20210202195101.GF20820@kadam> (raw)
In-Reply-To: <20210202190539.GE20820@kadam>

On Tue, Feb 02, 2021 at 10:05:39PM +0300, Dan Carpenter wrote:
> On Tue, Feb 02, 2021 at 07:53:17PM +0100, Pavel Machek wrote:
> > Hi!
> > 
> > > From: Dan Carpenter <dan.carpenter@oracle.com>
> > > 
> > > [ Upstream commit b552766c872f5b0d90323b24e4c9e8fa67486dd5 ]
> > > 
> > > The "bec" struct isn't necessarily always initialized. For example, the
> > > mcp251xfd_get_berr_counter() function doesn't initialize anything if the
> > > interface is down.
> > 
> > Well, yes... and = {} does not neccessarily initialize all of the
> > structure... for example padding.
> > 
> > It is really simple
> > 
> > struct can_berr_counter {
> > 	__u16 txerr;
> > 	__u16 rxerr;
> > };
> > 
> > but maybe something like alpha uses padding in such case, and memset
> > would be better?
> 
> I'm pretty sure nothing uses padding in this situation.  If it does then
> we need to re-work a bunch of code.

Not necessarily related but in theory a "= {};" assignment is a GCC
extension and it is supposed to zero out struct holes.  If the code
does "= {0};" then that's standard C, and will not necessarily fill
struct holes but I think GCC tries to.  The other complication is that
some GCC versions have bugs related to this?  We had a long thread about
this last August.

https://lore.kernel.org/lkml/20200801144030.GM24045@ziepe.ca/

Anyway, this code has no holes so it's not affected.

regards,
dan carpenter


  reply	other threads:[~2021-02-02 19:53 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-02 13:38 [PATCH 4.4 00/28] 4.4.255-rc1 review Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 01/28] ACPI: sysfs: Prefer "compatible" modalias Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 02/28] wext: fix NULL-ptr-dereference with cfg80211s lack of commit() Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 03/28] net: usb: qmi_wwan: added support for Thales Cinterion PLSx3 modem family Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 04/28] KVM: x86/pmu: Fix HW_REF_CPU_CYCLES event pseudo-encoding in intel_arch_events[] Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 05/28] mt7601u: fix kernel crash unplugging the device Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 06/28] mt7601u: fix rx buffer refcounting Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 07/28] y2038: futex: Move compat implementation into futex.c Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 08/28] futex: Move futex exit handling into futex code Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 09/28] futex: Replace PF_EXITPIDONE with a state Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 10/28] exit/exec: Seperate mm_release() Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 11/28] futex: Split futex_mm_release() for exit/exec Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 12/28] futex: Set task::futex_state to DEAD right after handling futex exit Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 13/28] futex: Mark the begin of futex exit explicitly Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 14/28] futex: Sanitize exit state handling Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 15/28] futex: Provide state handling for exec() as well Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 16/28] futex: Add mutex around futex exit Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 17/28] futex: Provide distinct return value when owner is exiting Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 18/28] futex: Prevent exit livelock Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 19/28] ARM: imx: build suspend-imx6.S with arm instruction set Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 20/28] netfilter: nft_dynset: add timeout extension to template Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 21/28] xfrm: Fix oops in xfrm_replay_advance_bmp Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 22/28] RDMA/cxgb4: Fix the reported max_recv_sge value Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 23/28] mac80211: pause TX while changing interface type Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 24/28] can: dev: prevent potential information leak in can_fill_info() Greg Kroah-Hartman
2021-02-02 18:53   ` Pavel Machek
2021-02-02 19:05     ` Dan Carpenter
2021-02-02 19:51       ` Dan Carpenter [this message]
2021-02-02 19:58         ` Pavel Machek
2021-02-02 13:38 ` [PATCH 4.4 25/28] iommu/vt-d: Gracefully handle DMAR units with no supported address widths Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 26/28] iommu/vt-d: Dont dereference iommu_device if IOMMU_API is not built Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 27/28] NFC: fix resource leak when target index is invalid Greg Kroah-Hartman
2021-02-02 13:38 ` [PATCH 4.4 28/28] NFC: fix possible resource leak Greg Kroah-Hartman
2021-02-02 17:19 ` [PATCH 4.4 00/28] 4.4.255-rc1 review Pavel Machek
2021-02-02 20:08 ` Jon Hunter
2021-02-03 10:00 ` Naresh Kamboju
2021-02-03 15:43 ` Shuah Khan
2021-02-03 20:40 ` Guenter Roeck

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=20210202195101.GF20820@kadam \
    --to=dan.carpenter@oracle.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mkl@pengutronix.de \
    --cc=pavel@ucw.cz \
    --cc=sashal@kernel.org \
    --cc=stable@vger.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.