diff options
| author | Jinbum Park <jinb.park7@gmail.com> | 2018-07-28 13:20:44 +0900 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-07-28 09:08:42 -0600 |
| commit | 55690c07b44a82cc3359ce0c233f4ba7d80ba145 (patch) | |
| tree | 1e73133269563bae2dd59e2790da18ee72618e18 | |
| parent | d43fdae7bac2def8c4314b5a49822cb7f08a45f1 (diff) | |
pktcdvd: Fix possible Spectre-v1 for pkt_devs
User controls @dev_minor which to be used as index of pkt_devs.
So, It can be exploited via Spectre-like attack. (speculative execution)
This kind of attack leaks address of pkt_devs, [1]
It leads an attacker to bypass security mechanism such as KASLR.
So sanitize @dev_minor before using it to prevent attack.
[1] https://github.com/jinb-park/linux-exploit/
tree/master/exploit-remaining-spectre-gadget/leak_pkt_devs.c
Signed-off-by: Jinbum Park <jinb.park7@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | drivers/block/pktcdvd.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index a4b4d524c3af..9bb7721c26fc 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -67,7 +67,7 @@ #include <scsi/scsi.h> #include <linux/debugfs.h> #include <linux/device.h> - +#include <linux/nospec.h> #include <linux/uaccess.h> #define DRIVER_NAME "pktcdvd" @@ -2254,6 +2254,8 @@ static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor) { if (dev_minor >= MAX_WRITERS) return NULL; + + dev_minor = array_index_nospec(dev_minor, MAX_WRITERS); return pkt_devs[dev_minor]; } |