diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-06-29 13:28:07 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-22 14:25:52 +0200 |
| commit | af4bae09386c787fbc2fa9b69a50d65eba4b6e30 (patch) | |
| tree | 6af40244d3cbf61b1c812565eefc936d7dbbeb0d | |
| parent | 517340a7ef476a44905fdb001c4a3dd824d99c3b (diff) | |
atm: zatm: Fix potential Spectre v1
[ Upstream commit ced9e191501e52b95e1b57b8e0db00943869eed0 ]
pool can be indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.
This issue was detected with the help of Smatch:
drivers/atm/zatm.c:1491 zatm_ioctl() warn: potential spectre issue
'zatm_dev->pool_info' (local cap)
Fix this by sanitizing pool before using it to index
zatm_dev->pool_info
Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].
[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/atm/zatm.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/atm/zatm.c b/drivers/atm/zatm.c index c302f47f6323..94712e1c5cf9 100644 --- a/drivers/atm/zatm.c +++ b/drivers/atm/zatm.c @@ -1481,6 +1481,8 @@ static int zatm_ioctl(struct atm_dev *dev,unsigned int cmd,void __user *arg) return -EFAULT; if (pool < 0 || pool > ZATM_LAST_POOL) return -EINVAL; + pool = array_index_nospec(pool, + ZATM_LAST_POOL + 1); if (copy_from_user(&info, &((struct zatm_pool_req __user *) arg)->info, sizeof(info))) return -EFAULT; |