diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2016-01-13 16:28:49 -0500 |
|---|---|---|
| committer | Simon Shields <keepcalm444@gmail.com> | 2016-03-10 22:01:30 +1100 |
| commit | b152bb944d40c369236e0d642f8296fdbacabfa2 (patch) | |
| tree | 0bd576573427d04ff56241b83f22559380dde3b2 | |
| parent | 0280906bb6e2548b41cb6788e3ec62feb1749db8 (diff) | |
| download | kernel_samsung_smdk4412-b152bb944d40c369236e0d642f8296fdbacabfa2.zip kernel_samsung_smdk4412-b152bb944d40c369236e0d642f8296fdbacabfa2.tar.gz kernel_samsung_smdk4412-b152bb944d40c369236e0d642f8296fdbacabfa2.tar.bz2 | |
BACKPORT: pagemap: do not leak physical addresses to non-privileged userspace
(cherry pick from commit ab676b7d6fbf4b294bf198fb27ade5b0e865c7ce)
As pointed by recent post[1] on exploiting DRAM physical imperfection,
/proc/PID/pagemap exposes sensitive information which can be used to do
attacks.
This disallows anybody without CAP_SYS_ADMIN to read the pagemap.
[1] http://googleprojectzero.blogspot.com/2015/03/exploiting-dram-rowhammer-bug-to-gain.html
[ Eventually we might want to do anything more finegrained, but for now
this is the simple model. - Linus ]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Seaborn <mseaborn@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 26038811
Change-Id: Icd68075a32ef6c9be1ae00ae9cf5a68bbe7f4e4f
| -rw-r--r-- | fs/proc/task_mmu.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 55a1f49..00e7ac4 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -862,9 +862,18 @@ out: return ret; } +static int pagemap_open(struct inode *inode, struct file *file) +{ + /* do not disclose physical addresses: attack vector */ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + return 0; +} + const struct file_operations proc_pagemap_operations = { .llseek = mem_lseek, /* borrow this */ .read = pagemap_read, + .open = pagemap_open, }; #endif /* CONFIG_PROC_PAGE_MONITOR */ |