Public bug reported:
Trusty 3.13 segfaults when running ldt_gdt_64 from the kernel's x86
selftests.
git bisect revealed that the following commit introduced the issue:
commit aeb315d60afee129d32558f4a4b356eec2e7da7b
Author: Andy Lutomirski <l...@kernel.org>
Date: Thu Jul 30 14:31:32 2015 -0700
x86/ldt: Make modify_ldt synchronous
CVE-2017-5754
commit 37868fe113ff2ba814b3b4eb12df214df555f8dc upstream.
modify_ldt() has questionable locking and does not synchronize
threads. Improve it: redesign the locking and synchronize all
threads' LDTs using an IPI on all modifications.
This will dramatically slow down modify_ldt in multithreaded
programs, but there shouldn't be any multithreaded programs that
care about modify_ldt's performance in the first place.
This fixes some fallout from the CVE-2015-5157 fixes.
Signed-off-by: Andy Lutomirski <l...@kernel.org>
Reviewed-by: Borislav Petkov <b...@suse.de>
Cc: Andrew Cooper <andrew.coop...@citrix.com>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrov...@oracle.com>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Brian Gerst <brge...@gmail.com>
Cc: Denys Vlasenko <dvlas...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Jan Beulich <jbeul...@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Sasha Levin <sasha.le...@oracle.com>
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Link:
http://lkml.kernel.org/r/4c6978476782160600471bd865b318db34c7b628.1438291540.git.l...@kernel.org
Signed-off-by: Ingo Molnar <mi...@kernel.org>
Signed-off-by: Jiri Slaby <jsl...@suse.cz>
(cherry picked from commit 62fc7228f8cc8c89ecbd37008a0495ac28e41c5c)
Signed-off-by: Juerg Haefliger <juerg.haefli...@canonical.com>
Signed-off-by: Stefan Bader <stefan.ba...@canonical.com>
** Affects: linux (Ubuntu)
Importance: Undecided
Status: Incomplete
** Affects: linux (Ubuntu Trusty)
Importance: Undecided
Status: New
--
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1755817
Title:
Segmentation fault in ldt_gdt_64
Status in linux package in Ubuntu:
Incomplete
Status in linux source package in Trusty:
New
Bug description:
Trusty 3.13 segfaults when running ldt_gdt_64 from the kernel's x86
selftests.
git bisect revealed that the following commit introduced the issue:
commit aeb315d60afee129d32558f4a4b356eec2e7da7b
Author: Andy Lutomirski <l...@kernel.org>
Date: Thu Jul 30 14:31:32 2015 -0700
x86/ldt: Make modify_ldt synchronous
CVE-2017-5754
commit 37868fe113ff2ba814b3b4eb12df214df555f8dc upstream.
modify_ldt() has questionable locking and does not synchronize
threads. Improve it: redesign the locking and synchronize all
threads' LDTs using an IPI on all modifications.
This will dramatically slow down modify_ldt in multithreaded
programs, but there shouldn't be any multithreaded programs that
care about modify_ldt's performance in the first place.
This fixes some fallout from the CVE-2015-5157 fixes.
Signed-off-by: Andy Lutomirski <l...@kernel.org>
Reviewed-by: Borislav Petkov <b...@suse.de>
Cc: Andrew Cooper <andrew.coop...@citrix.com>
Cc: Andy Lutomirski <l...@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrov...@oracle.com>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Brian Gerst <brge...@gmail.com>
Cc: Denys Vlasenko <dvlas...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Jan Beulich <jbeul...@suse.com>
Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Sasha Levin <sasha.le...@oracle.com>
Cc: Steven Rostedt <rost...@goodmis.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Link:
http://lkml.kernel.org/r/4c6978476782160600471bd865b318db34c7b628.1438291540.git.l...@kernel.org
Signed-off-by: Ingo Molnar <mi...@kernel.org>
Signed-off-by: Jiri Slaby <jsl...@suse.cz>
(cherry picked from commit 62fc7228f8cc8c89ecbd37008a0495ac28e41c5c)
Signed-off-by: Juerg Haefliger <juerg.haefli...@canonical.com>
Signed-off-by: Stefan Bader <stefan.ba...@canonical.com>
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1755817/+subscriptions
--
Mailing list: https://launchpad.net/~kernel-packages
Post to : kernel-packages@lists.launchpad.net
Unsubscribe : https://launchpad.net/~kernel-packages
More help : https://help.launchpad.net/ListHelp
