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authorGustavo A. R. Silva <gustavo@embeddedor.com>2018-06-29 13:28:07 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-22 14:28:43 +0200
commit43c9207d029648dce52a45cd07dfb832d8a7957a (patch)
tree3169b584d8e5f5cd04ebd288f1ae4511ed55aac6 /drivers/atm
parentf93d65939a4a80f31e50af88bbd5fcae33266009 (diff)
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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>
Diffstat (limited to 'drivers/atm')
-rw-r--r--drivers/atm/zatm.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/atm/zatm.c b/drivers/atm/zatm.c
index a8d2eb0ceb8d..2c288d1f42bb 100644
--- a/drivers/atm/zatm.c
+++ b/drivers/atm/zatm.c
@@ -1483,6 +1483,8 @@ 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;