diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2015-03-09 23:11:12 +0200 |
|---|---|---|
| committer | Christian Bejram <cbejram@google.com> | 2016-01-22 11:07:34 -0800 |
| commit | 2d62d5ff3c5d0c07c85f4230bab3e1fa1b53a066 (patch) | |
| tree | 9fc5af12b9fdc42693efe4b3a0549a3c16d4e40e | |
| parent | cdf641bfeb94ef6ddc41946a9172843be970892c (diff) | |
BACKPORT: pagemap: do not leak physical addresses to non-privileged userspaceandroid-6.0.1_r0.29
(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: 25739721
Change-Id: I5582c993dbeb0b7287e6d41b57e494d123d33083
Signed-off-by: Christian Bejram <cbejram@google.com>
| -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 624698e29506..865050b88704 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1181,9 +1181,18 @@ 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 */ |