This is a note to let you know that I've just added the patch titled
/proc/iomem: only expose physical resource addresses to privileged users
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
proc-iomem-only-expose-physical-resource-addresses-to-privileged-users.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 51d7b120418e99d6b3bf8df9eb3cc31e8171dee4 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Thu, 14 Apr 2016 12:05:37 -0700
Subject: /proc/iomem: only expose physical resource addresses to privileged users
From: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
commit 51d7b120418e99d6b3bf8df9eb3cc31e8171dee4 upstream.
In commit c4004b02f8e5b ("x86: remove the kernel code/data/bss resources
from /proc/iomem") I was hoping to remove the phyiscal kernel address
data from /proc/iomem entirely, but that had to be reverted because some
system programs actually use it.
This limits all the detailed resource information to properly
credentialed users instead.
[sumits: this is used in Ubuntu as a fix for CVE-2015-8944]
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/resource.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -105,16 +105,25 @@ static int r_show(struct seq_file *m, vo
{
struct resource *root = m->private;
struct resource *r = v, *p;
+ unsigned long long start, end;
int width = root->end < 0x10000 ? 4 : 8;
int depth;
for (depth = 0, p = r; depth < MAX_IORES_LEVEL; depth++, p = p->parent)
if (p->parent == root)
break;
+
+ if (file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN)) {
+ start = r->start;
+ end = r->end;
+ } else {
+ start = end = 0;
+ }
+
seq_printf(m, "%*s%0*llx-%0*llx : %s\n",
depth * 2, "",
- width, (unsigned long long) r->start,
- width, (unsigned long long) r->end,
+ width, start,
+ width, end,
r->name ? r->name : "<BAD>");
return 0;
}
Patches currently in stable-queue which might be from torvalds@xxxxxxxxxxxxxxxxxxxx are
queue-4.4/sched-cgroup-move-sched_online_group-back-into-css_online-to-fix-crash.patch
queue-4.4/proc-iomem-only-expose-physical-resource-addresses-to-privileged-users.patch
queue-4.4/drm-vmwgfx-fix-gcc-7.1.1-warning.patch
queue-4.4/isdn-i4l-fix-buffer-overflow.patch
queue-4.4/make-file-credentials-available-to-the-seqfile-interfaces.patch