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From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Haakon Bugge <haakon.bugge@oracle.com>
Cc: Jane Chu <jane.chu@oracle.com>, Petr Mladek <pmladek@suse.com>,
	"rostedt@goodmis.org" <rostedt@goodmis.org>,
	"senozhatsky@chromium.org" <senozhatsky@chromium.org>,
	"linux@rasmusvillemoes.dk" <linux@rasmusvillemoes.dk>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	John Haxby <john.haxby@oracle.com>
Subject: Re: [PATCH] vsprintf: protect kernel from panic due to non-canonical pointer dereference
Date: Wed, 19 Oct 2022 14:25:27 +0300	[thread overview]
Message-ID: <Y0/ep9LS5jVTrUWI@smile.fi.intel.com> (raw)
In-Reply-To: <198982F5-E94C-4F95-8197-FE69EFBA670F@oracle.com>

On Wed, Oct 19, 2022 at 10:43:07AM +0000, Haakon Bugge wrote:
> > On 18 Oct 2022, at 22:49, Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:
> > On Tue, Oct 18, 2022 at 08:30:01PM +0000, Jane Chu wrote:

...

> > Obviously, to see the crash. And let kernel _to crash_. Isn't it what we need
> > to see a bug as early as possible?
> 
> If you follow that argument, why doesn't the kernel crash when the pointer
> is, e.g., a NULL pointer? According to you, shouldn't it crash a early as
> possible in that case also?

Because it is _special_. It's not just an invalid pointer. There may be
very well good cases where we supply (valid!) NULL pointers to the printf().

-- 
With Best Regards,
Andy Shevchenko




  reply	other threads:[~2022-10-19 11:25 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20221017191611.2577466-1-jane.chu@oracle.com>
     [not found] ` <Y02sENwhtpsx5yhP@smile.fi.intel.com>
     [not found]   ` <5d987403-a7bf-8996-d639-c99edeaabcdf@oracle.com>
     [not found]     ` <Y06f4EwisLTU0rEz@alley>
2022-10-18 18:56       ` Jane Chu
2022-10-18 19:28         ` Randy Dunlap
2022-10-18 19:58           ` Jane Chu
2022-10-18 20:07         ` Andy Shevchenko
2022-10-18 20:30           ` Jane Chu
2022-10-18 20:49             ` Andy Shevchenko
2022-10-19 10:43               ` Haakon Bugge
2022-10-19 11:25                 ` Andy Shevchenko [this message]
2022-10-19 18:36               ` Jane Chu
2022-10-19 19:26                 ` Andy Shevchenko
2022-10-19 20:16                   ` Jane Chu
2022-10-20  7:44               ` Petr Mladek
2022-10-20  9:18                 ` Petr Mladek
2022-10-20 13:57                 ` Andy Shevchenko

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