From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To: Jane Chu <jane.chu@oracle.com>
Cc: pmladek@suse.com, rostedt@goodmis.org, senozhatsky@chromium.org,
linux@rasmusvillemoes.dk, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] vsprintf: protect kernel from panic due to non-canonical pointer dereference
Date: Mon, 17 Oct 2022 22:25:04 +0300 [thread overview]
Message-ID: <Y02sENwhtpsx5yhP@smile.fi.intel.com> (raw)
In-Reply-To: <20221017191611.2577466-1-jane.chu@oracle.com>
On Mon, Oct 17, 2022 at 01:16:11PM -0600, Jane Chu wrote:
> While debugging a separate issue, it was found that an invalid string
> pointer could very well contain a non-canical address, such as
> 0x7665645f63616465. In that case, this line of defense isn't enough
> to protect the kernel from crashing due to general protection fault
>
> if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
> return "(efault)";
>
> So instead, use kern_addr_valid() to validate the string pointer.
How did you check that value of the (invalid string) pointer?
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2022-10-17 19:26 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-17 19:16 [PATCH] vsprintf: protect kernel from panic due to non-canonical pointer dereference Jane Chu
2022-10-17 19:25 ` Andy Shevchenko [this message]
2022-10-17 19:31 ` Jane Chu
2022-10-18 12:45 ` Petr Mladek
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
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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