Re: [PATCH] lkdtm: print real addresses
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2018-11-27 07:43:33
Also in:
lkml
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2018-11-27 07:43:33
Also in:
lkml
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?