From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Kees Cook <keescook@chromium.org>, Arnd Bergmann <arnd@arndb.de>,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] lkdtm: print real addresses
Date: Tue, 27 Nov 2018 08:43:27 +0100 [thread overview]
Message-ID: <20181127074327.GD13965@kroah.com> (raw)
In-Reply-To: <edfe11c6d1f9bb0a7c2cee655895dfeedc1dda5e.1541613057.git.christophe.leroy@c-s.fr>
On Wed, Nov 07, 2018 at 08:14:10PM +0000, Christophe Leroy wrote:
> Today, when doing a lkdtm test before the readiness of the
> random generator, (ptrval) is printed instead of the address
> at which it perform the fault:
>
> [ 1597.337030] lkdtm: Performing direct entry EXEC_USERSPACE
> [ 1597.337142] lkdtm: attempting ok execution at (ptrval)
> [ 1597.337398] lkdtm: attempting bad execution at (ptrval)
> [ 1597.337460] kernel tried to execute user page (77858000) -exploit attempt? (uid: 0)
> [ 1597.344769] Unable to handle kernel paging request for instruction fetch
> [ 1597.351392] Faulting instruction address: 0x77858000
> [ 1597.356312] Oops: Kernel access of bad area, sig: 11 [#1]
>
> If the lkdtm test is done later on, it prints an hashed address.
>
> In both cases this is pointless. The purpose of the test is to
> ensure the kernel generates an Oops at the expected address,
> so real addresses needs to be printed. This patch fixes that.
I am pretty sure this is intentional. Kees?
WARNING: multiple messages have this Message-ID (diff)
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: linuxppc-dev@lists.ozlabs.org, Kees Cook <keescook@chromium.org>,
Arnd Bergmann <arnd@arndb.de>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] lkdtm: print real addresses
Date: Tue, 27 Nov 2018 08:43:27 +0100 [thread overview]
Message-ID: <20181127074327.GD13965@kroah.com> (raw)
In-Reply-To: <edfe11c6d1f9bb0a7c2cee655895dfeedc1dda5e.1541613057.git.christophe.leroy@c-s.fr>
On Wed, Nov 07, 2018 at 08:14:10PM +0000, Christophe Leroy wrote:
> Today, when doing a lkdtm test before the readiness of the
> random generator, (ptrval) is printed instead of the address
> at which it perform the fault:
>
> [ 1597.337030] lkdtm: Performing direct entry EXEC_USERSPACE
> [ 1597.337142] lkdtm: attempting ok execution at (ptrval)
> [ 1597.337398] lkdtm: attempting bad execution at (ptrval)
> [ 1597.337460] kernel tried to execute user page (77858000) -exploit attempt? (uid: 0)
> [ 1597.344769] Unable to handle kernel paging request for instruction fetch
> [ 1597.351392] Faulting instruction address: 0x77858000
> [ 1597.356312] Oops: Kernel access of bad area, sig: 11 [#1]
>
> If the lkdtm test is done later on, it prints an hashed address.
>
> In both cases this is pointless. The purpose of the test is to
> ensure the kernel generates an Oops at the expected address,
> so real addresses needs to be printed. This patch fixes that.
I am pretty sure this is intentional. Kees?
next prev parent reply other threads:[~2018-11-27 7:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-07 20:14 [PATCH] lkdtm: print real addresses Christophe Leroy
2018-11-07 20:14 ` Christophe Leroy
2018-11-27 7:43 ` Greg Kroah-Hartman [this message]
2018-11-27 7:43 ` Greg Kroah-Hartman
2018-11-27 17:18 ` Kees Cook
2018-11-27 17:18 ` Kees Cook
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