diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-05-03 13:17:12 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-05-04 12:52:47 -0400 |
| commit | 2be147f7459db5bbf292e0a6f135037b55e20b39 (patch) | |
| tree | 24d26b101cb213841eb1b907e42f8c899b639ab2 | |
| parent | 72f17baf2352ded6a1d3f4bb2d15da8c678cd2cb (diff) | |
atm: zatm: Fix potential Spectre v1
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:1462 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
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/atm/zatm.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/atm/zatm.c b/drivers/atm/zatm.c index 1ef67db03c8e..9c9a22958717 100644 --- a/drivers/atm/zatm.c +++ b/drivers/atm/zatm.c @@ -28,6 +28,7 @@ #include <asm/io.h> #include <linux/atomic.h> #include <linux/uaccess.h> +#include <linux/nospec.h> #include "uPD98401.h" #include "uPD98402.h" @@ -1458,6 +1459,8 @@ 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); spin_lock_irqsave(&zatm_dev->lock, flags); info = zatm_dev->pool_info[pool]; if (cmd == ZATM_GETPOOLZ) { |