Messages in this thread | | | Date | Tue, 14 Jan 2014 10:32:06 -0800 | Subject | Re: [x86, kaslr] BUG: kernel boot hang | From | Kees Cook <> |
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On Tue, Jan 14, 2014 at 8:02 AM, H. Peter Anvin <hpa@linux.intel.com> wrote: > On 01/14/2014 05:31 AM, Fengguang Wu wrote: >> Greetings, >> >> I got the below dmesg and the first bad commit is >> >> commit 82fa9637a2ba285bcc7c5050c73010b2c1b3d803 >> Author: Kees Cook <keescook@chromium.org> >> AuthorDate: Thu Oct 10 17:18:16 2013 -0700 >> Commit: H. Peter Anvin <hpa@linux.intel.com> >> CommitDate: Sun Oct 13 03:12:19 2013 -0700 >> >> x86, kaslr: Select random position from e820 maps >> >> Counts available alignment positions across all e820 maps, and chooses >> one randomly for the new kernel base address, making sure not to collide >> with unsafe memory areas. >> >> Signed-off-by: Kees Cook <keescook@chromium.org> >> Link: http://lkml.kernel.org/r/1381450698-28710-5-git-send-email-keescook@chromium.org >> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> >> >> Note that there are many other warning/errors and it's not very >> reproducible, so this report might be wrong. >> >> =================================================== >> PARENT COMMIT NOT CLEAN. LOOK OUT FOR WRONG BISECT! >> =================================================== >> > > I wonder if this is in any way related to the fact that the ELF parser > we have in the decompressor is quite frankly complete crap... it assumes > that all sections can only be moved downward.
Not that this would change the code here, but I notice tip:x86/kaslr isn't fully up to date. It's still missing the two most recent commits:
https://git.kernel.org/cgit/linux/kernel/git/kees/linux.git/log/?h=kaslr-c-v8
"x86, kaslr: clarify RANDOMIZE_BASE_MAX_OFFSET" "x86, kaslr: remove unused including <linux/version.h>"
-Kees
-- Kees Cook Chrome OS Security
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