pve-kernel-lowlatency-qoup/CVE-2017-1000364-mm-mmap.c-do-not-blow-on-PROT_NONE-MAP_FIXED-holes-i.patch
Thomas Lamprecht 4c390211d8 add CVE fixes
CVE-2017-1000364 (rather bugfix for the original CVE fix):
 * mm/mmap.c: expand_downwards: don't require the gap if !vm_prev
 * mm/mmap.c: do not blow on PROT_NONE MAP_FIXED holes in the stack

CVE-2017-1000365: fs/exec.c: account for argv/envp pointers

CVE-2017-10810: drm/virtio: don't leak bo on drm_gem_object_init
 failure

CVE-2017-7482: rxrpc: Fix several cases where a padded len isn't
 checked in ticket decode

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
2017-07-19 09:46:19 +02:00

73 lines
2.8 KiB
Diff

From 3e4f09eef73ad12d4876e24daf52a0dc0891d7da Mon Sep 17 00:00:00 2001
From: Michal Hocko <mhocko@suse.com>
Date: Mon, 17 Jul 2017 14:53:28 +0200
Subject: [PATCH 1/2] mm/mmap.c: do not blow on PROT_NONE MAP_FIXED holes in
the stack
Commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") has
introduced a regression in some rust and Java environments which are
trying to implement their own stack guard page. They are punching a new
MAP_FIXED mapping inside the existing stack Vma.
This will confuse expand_{downwards,upwards} into thinking that the
stack expansion would in fact get us too close to an existing non-stack
vma which is a correct behavior wrt safety. It is a real regression on
the other hand.
Let's work around the problem by considering PROT_NONE mapping as a part
of the stack. This is a gros hack but overflowing to such a mapping
would trap anyway an we only can hope that usespace knows what it is
doing and handle it propely.
Fixes: 1be7107fbe18 ("mm: larger stack guard gap, between vmas")
Link: http://lkml.kernel.org/r/20170705182849.GA18027@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Debugged-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CVE-2017-1000364
(cherry picked from commit 561b5e0709e4a248c67d024d4d94b6e31e3edf2f)
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Acked-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
---
mm/mmap.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/mm/mmap.c b/mm/mmap.c
index ef78a5ca5599..9fabd8c82f38 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -2240,7 +2240,8 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
gap_addr = TASK_SIZE;
next = vma->vm_next;
- if (next && next->vm_start < gap_addr) {
+ if (next && next->vm_start < gap_addr &&
+ (next->vm_flags & (VM_WRITE|VM_READ|VM_EXEC))) {
if (!(next->vm_flags & VM_GROWSUP))
return -ENOMEM;
/* Check that both stack segments have the same anon_vma? */
@@ -2324,7 +2325,8 @@ int expand_downwards(struct vm_area_struct *vma,
if (gap_addr > address)
return -ENOMEM;
prev = vma->vm_prev;
- if (prev && prev->vm_end > gap_addr) {
+ if (prev && prev->vm_end > gap_addr &&
+ (prev->vm_flags & (VM_WRITE|VM_READ|VM_EXEC))) {
if (!(prev->vm_flags & VM_GROWSDOWN))
return -ENOMEM;
/* Check that both stack segments have the same anon_vma? */
--
2.11.0