projects / pve-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 035dbe67 FG |
1 | From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 |
| 2 | From: Dave Hansen <dave.hansen@linux.intel.com> | |
| 3 | Date: Sat, 6 Jan 2018 18:41:14 +0100 | |
| 4 | Subject: [PATCH] x86/tboot: Unbreak tboot with PTI enabled | |
| 5 | MIME-Version: 1.0 | |
| 6 | Content-Type: text/plain; charset=UTF-8 | |
| 7 | Content-Transfer-Encoding: 8bit | |
| 8 | ||
| 9 | CVE-2017-5754 | |
| 10 | ||
| 11 | This is another case similar to what EFI does: create a new set of | |
| 12 | page tables, map some code at a low address, and jump to it. PTI | |
| 13 | mistakes this low address for userspace and mistakenly marks it | |
| 14 | non-executable in an effort to make it unusable for userspace. | |
| 15 | ||
| 16 | Undo the poison to allow execution. | |
| 17 | ||
| 18 | Fixes: 385ce0ea4c07 ("x86/mm/pti: Add Kconfig") | |
| 19 | Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> | |
| 20 | Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> | |
| 21 | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> | |
| 22 | Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> | |
| 23 | Cc: Tim Chen <tim.c.chen@linux.intel.com> | |
| 24 | Cc: Jon Masters <jcm@redhat.com> | |
| 25 | Cc: Dave Hansen <dave.hansen@intel.com> | |
| 26 | Cc: Andi Kleen <andi@firstfloor.org> | |
| 27 | Cc: Jeff Law <law@redhat.com> | |
| 28 | Cc: Paolo Bonzini <pbonzini@redhat.com> | |
| 29 | Cc: Linus Torvalds <torvalds@linux-foundation.org> | |
| 30 | Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> | |
| 31 | Cc: David" <dwmw@amazon.co.uk> | |
| 32 | Cc: Nick Clifton <nickc@redhat.com> | |
| 33 | Cc: stable@vger.kernel.org | |
| 34 | Link: https://lkml.kernel.org/r/20180108102805.GK25546@redhat.com | |
| 35 | (cherry picked from commit 262b6b30087246abf09d6275eb0c0dc421bcbe38) | |
| 36 | Signed-off-by: Andy Whitcroft <apw@canonical.com> | |
| 37 | Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> | |
| 38 | (cherry picked from commit f03e9108405491791f0b883a2d95e2620ddfce64) | |
| 39 | Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com> | |
| 40 | --- | |
| 41 | arch/x86/kernel/tboot.c | 1 + | |
| 42 | 1 file changed, 1 insertion(+) | |
| 43 | ||
| 44 | diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c | |
| 45 | index a4eb27918ceb..75869a4b6c41 100644 | |
| 46 | --- a/arch/x86/kernel/tboot.c | |
| 47 | +++ b/arch/x86/kernel/tboot.c | |
| 48 | @@ -127,6 +127,7 @@ static int map_tboot_page(unsigned long vaddr, unsigned long pfn, | |
| 49 | p4d = p4d_alloc(&tboot_mm, pgd, vaddr); | |
| 50 | if (!p4d) | |
| 51 | return -1; | |
| 52 | + pgd->pgd &= ~_PAGE_NX; | |
| 53 | pud = pud_alloc(&tboot_mm, p4d, vaddr); | |
| 54 | if (!pud) | |
| 55 | return -1; | |
| 56 | -- | |
| 57 | 2.14.2 | |
| 58 |