diff options
| author | Kirill A. Shutemov <[email protected]> | 2015-03-09 23:11:12 +0200 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2015-03-17 09:31:30 -0700 |
| commit | ab676b7d6fbf4b294bf198fb27ade5b0e865c7ce (patch) | |
| tree | 93fdcd656a687ca3fa5f717f9ce078cd8aea6c70 | |
| parent | 06e5801b8cb3fc057d88cb4dc03c0b64b2744cda (diff) | |
pagemap: do not leak physical addresses to non-privileged userspace
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 <[email protected]>
Acked-by: Konstantin Khlebnikov <[email protected]>
Acked-by: Andy Lutomirski <[email protected]>
Cc: Pavel Emelyanov <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Mark Seaborn <[email protected]>
Cc: [email protected]
Signed-off-by: Linus Torvalds <[email protected]>
| -rw-r--r-- | fs/proc/task_mmu.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 956b75d61809..6dee68d013ff 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1325,6 +1325,9 @@ out: static int pagemap_open(struct inode *inode, struct file *file) { + /* do not disclose physical addresses: attack vector */ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; pr_warn_once("Bits 55-60 of /proc/PID/pagemap entries are about " "to stop being page-shift some time soon. See the " "linux/Documentation/vm/pagemap.txt for details.\n"); |