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From: Leon Romanovsky <leon@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: rds-devel@oss.oracle.com, Arnd Bergmann <arnd@arndb.de>,
	linux-rdma@vger.kernel.org, netdev@vger.kernel.org,
	Santosh Shilimkar <santosh.shilimkar@oracle.com>,
	linux-kernel@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Jason Gunthorpe <jgg@ziepe.ca>, Jakub Kicinski <kuba@kernel.org>,
	linux-kernel-mentees@lists.linuxfoundation.org,
	Peilin Ye <yepeilin.cs@gmail.com>,
	Dan Carpenter <dan.carpenter@oracle.com>
Subject: Re: [Linux-kernel-mentees] [PATCH net] rds: Prevent kernel-infoleak in rds_notify_queue_get()
Date: Sat, 1 Aug 2020 08:38:33 +0300	[thread overview]
Message-ID: <20200801053833.GK75549@unreal> (raw)
In-Reply-To: <20200731171924.GA2014207@kroah.com>

On Fri, Jul 31, 2020 at 07:19:24PM +0200, Greg Kroah-Hartman wrote:
> On Fri, Jul 31, 2020 at 11:36:04AM -0300, Jason Gunthorpe wrote:
> > On Fri, Jul 31, 2020 at 04:21:48PM +0200, Greg Kroah-Hartman wrote:
> >
> > > > The spec was updated in C11 to require zero'ing padding when doing
> > > > partial initialization of aggregates (eg = {})
> > > >
> > > > """if it is an aggregate, every member is initialized (recursively)
> > > > according to these rules, and any padding is initialized to zero
> > > > bits;"""
> > >
> > > But then why does the compilers not do this?
> >
> > Do you have an example?
>
> At the moment, no, but we have had them in the past due to security
> issues we have had to fix for this.

Is it still relevant after bump of required GCC version to build kernel?

I afraid that without solid example such changes will start to be
treated with cargo cult.

Jason,

I'm using {} instead of {0} because of this GCC bug.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119

Thanks
_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

WARNING: multiple messages have this Message-ID (diff)
From: Leon Romanovsky <leon@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>, Peilin Ye <yepeilin.cs@gmail.com>,
	Santosh Shilimkar <santosh.shilimkar@oracle.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-kernel-mentees@lists.linuxfoundation.org,
	netdev@vger.kernel.org, linux-rdma@vger.kernel.org,
	rds-devel@oss.oracle.com, linux-kernel@vger.kernel.org
Subject: Re: [Linux-kernel-mentees] [PATCH net] rds: Prevent kernel-infoleak in rds_notify_queue_get()
Date: Sat, 1 Aug 2020 08:38:33 +0300	[thread overview]
Message-ID: <20200801053833.GK75549@unreal> (raw)
In-Reply-To: <20200731171924.GA2014207@kroah.com>

On Fri, Jul 31, 2020 at 07:19:24PM +0200, Greg Kroah-Hartman wrote:
> On Fri, Jul 31, 2020 at 11:36:04AM -0300, Jason Gunthorpe wrote:
> > On Fri, Jul 31, 2020 at 04:21:48PM +0200, Greg Kroah-Hartman wrote:
> >
> > > > The spec was updated in C11 to require zero'ing padding when doing
> > > > partial initialization of aggregates (eg = {})
> > > >
> > > > """if it is an aggregate, every member is initialized (recursively)
> > > > according to these rules, and any padding is initialized to zero
> > > > bits;"""
> > >
> > > But then why does the compilers not do this?
> >
> > Do you have an example?
>
> At the moment, no, but we have had them in the past due to security
> issues we have had to fix for this.

Is it still relevant after bump of required GCC version to build kernel?

I afraid that without solid example such changes will start to be
treated with cargo cult.

Jason,

I'm using {} instead of {0} because of this GCC bug.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119

Thanks

  parent reply	other threads:[~2020-08-01  5:38 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-30 19:20 [Linux-kernel-mentees] [PATCH net] rds: Prevent kernel-infoleak in rds_notify_queue_get() Peilin Ye
2020-07-30 19:20 ` Peilin Ye
2020-07-30 19:29 ` santosh.shilimkar
2020-07-30 19:29   ` santosh.shilimkar
2020-07-31  4:53 ` Leon Romanovsky
2020-07-31  4:53   ` Leon Romanovsky
2020-07-31  5:33   ` Greg Kroah-Hartman
2020-07-31  5:33     ` Greg Kroah-Hartman
2020-07-31  5:33     ` Greg Kroah-Hartman
2020-07-31  5:33       ` Greg Kroah-Hartman
2020-07-31  6:29       ` Andy Shevchenko
2020-07-31  7:00         ` Leon Romanovsky
2020-07-31  7:00           ` Leon Romanovsky
2020-07-31  7:05           ` Andy Shevchenko
2020-07-31  7:05             ` Andy Shevchenko
2020-07-31 14:04       ` Jason Gunthorpe
2020-07-31 14:04         ` Jason Gunthorpe
2020-07-31 14:21         ` Greg Kroah-Hartman
2020-07-31 14:21           ` Greg Kroah-Hartman
2020-07-31 14:36           ` Jason Gunthorpe
2020-07-31 14:36             ` Jason Gunthorpe
2020-07-31 17:19             ` Greg Kroah-Hartman
2020-07-31 17:19               ` Greg Kroah-Hartman
2020-07-31 18:27               ` Jason Gunthorpe
2020-07-31 18:27                 ` Jason Gunthorpe
2020-08-01  8:00                 ` Dan Carpenter
2020-08-01  8:00                   ` Dan Carpenter
2020-08-01 14:40                   ` Jason Gunthorpe
2020-08-01 14:40                     ` Jason Gunthorpe
2020-08-03  9:34                     ` Dan Carpenter
2020-08-03  9:34                       ` Dan Carpenter
2020-08-01  5:38               ` Leon Romanovsky [this message]
2020-08-01  5:38                 ` Leon Romanovsky
2020-08-02 22:10                 ` Jason Gunthorpe
2020-08-02 22:10                   ` Jason Gunthorpe
2020-08-02 22:23                   ` Joe Perches
2020-08-02 22:23                     ` Joe Perches
2020-08-02 22:28                     ` Jason Gunthorpe
2020-08-02 22:28                       ` Jason Gunthorpe
2020-08-02 22:45                       ` Joe Perches
2020-08-02 22:45                         ` Joe Perches
2020-08-03  4:58                         ` Leon Romanovsky
2020-08-03  4:58                           ` Leon Romanovsky
2020-08-03 23:06                         ` Jason Gunthorpe
2020-08-03 23:06                           ` Jason Gunthorpe
2020-08-08 22:57                           ` Jack Leadford
2020-08-08 22:57                             ` Jack Leadford
2020-08-09  7:04                             ` Leon Romanovsky
2020-08-09  7:04                               ` Leon Romanovsky
2020-08-14 17:07                             ` Jason Gunthorpe
2020-08-14 17:07                               ` Jason Gunthorpe
2020-07-31  6:31   ` Andy Shevchenko
2020-07-31  9:59   ` Dan Carpenter
2020-07-31  9:59     ` Dan Carpenter
2020-07-31 11:14     ` Håkon Bugge
2020-07-31 11:14       ` Håkon Bugge
2020-07-31 11:59       ` Greg Kroah-Hartman
2020-07-31 11:59         ` Greg Kroah-Hartman
2020-07-31 12:03         ` Håkon Bugge
2020-07-31 12:03           ` Håkon Bugge
2020-07-31 23:54 ` David Miller
2020-07-31 23:54   ` David Miller

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