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
next prev parent 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
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