From: Petr Mladek <pmladek@suse.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Qian Cai <cai@gmx.us>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
linux-kernel@vger.kernel.org, "Tobin C. Harding" <me@tobin.cc>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Subject: Re: WARNING: CPU: 26 PID: 64391 at lib/vsprintf.c:2193 set_precision+0x84/0x90
Date: Wed, 14 Nov 2018 00:05:12 +0100 [thread overview]
Message-ID: <20181113230511.5di75uyht7ecdcvl@pathway.suse.cz> (raw)
In-Reply-To: <20181113142317.379dbaf7@vmware.local.home>
On Tue 2018-11-13 14:23:17, Steven Rostedt wrote:
> On Tue, 13 Nov 2018 13:58:18 -0500
> Qian Cai <cai@gmx.us> wrote:
>
> > > Care to print the len and name parameters before this line?
> > len = 60612; name =
>
> How big are pages on arm64? Because we shouldn't get to this path if
> the string is bigger than PAGE_SIZE. But I know that on PPC64,
> PAGE_SIZE can be 64K, and 60612 is less than that. Thus, if we get
> there, the test is against signed int:16 (16 bit signed integer) that
> can go up to most 32768. If the string size is bigger than that, you
> would get this error.
>
> I would just say to ignore it.
I tend to agree.
> The only thing that can happen if
> someone does this is to trigger the warning. Unless if it is considered
> a form of DOS, where userspace just bombards the console by triggering
> this waring.
We are actually on the safe side because it is WARN_ONCE().
> But I don't see a problem with the actual design. There's
> no reason we should be processing string variables bigger than 32768 in
> vsprintf.
It is not even needed in this case. The string is limited also by
MODULE_NAME_LEN.
Best Regards,
Petr
next prev parent reply other threads:[~2018-11-13 23:05 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 16:55 WARNING: CPU: 26 PID: 64391 at lib/vsprintf.c:2193 set_precision+0x84/0x90 Qian Cai
2018-11-13 17:20 ` Geert Uytterhoeven
2018-11-13 17:32 ` Andy Shevchenko
2018-11-13 17:29 ` Andy Shevchenko
2018-11-13 18:58 ` Qian Cai
2018-11-13 19:23 ` Steven Rostedt
2018-11-13 23:05 ` Petr Mladek [this message]
2018-11-14 9:38 ` Andy Shevchenko
2018-11-14 19:29 ` Petr Mladek
2018-11-14 20:35 ` Qian Cai
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