sl is controlled by user-space, hence leading to a potential
exploitation of the Spectre variant 1 vulnerability.
Fix this by sanitizing sl before using it to index ibp->sl_to_sc.
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://lore.kernel.org/lkml/[email protected]/
Cc: [email protected]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/infiniband/hw/hfi1/verbs.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/infiniband/hw/hfi1/verbs.c b/drivers/infiniband/hw/hfi1/verbs.c
index f4ca436118ab..9f53f63b1453 100644
--- a/drivers/infiniband/hw/hfi1/verbs.c
+++ b/drivers/infiniband/hw/hfi1/verbs.c
@@ -54,6 +54,7 @@
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <rdma/opa_addr.h>
+#include <linux/nospec.h>
#include "hfi.h"
#include "common.h"
@@ -1537,6 +1538,7 @@ static int hfi1_check_ah(struct ib_device *ibdev, struct rdma_ah_attr *ah_attr)
sl = rdma_ah_get_sl(ah_attr);
if (sl >= ARRAY_SIZE(ibp->sl_to_sc))
return -EINVAL;
+ sl = array_index_nospec(sl, ARRAY_SIZE(ibp->sl_to_sc));
sc5 = ibp->sl_to_sc[sl];
if (sc_to_vlt(dd, sc5) > num_vls && sc_to_vlt(dd, sc5) != 0xf)
--
2.22.0
On Wed, 2019-07-31 at 12:54 -0500, Gustavo A. R. Silva wrote:
> sl is controlled by user-space, hence leading to a potential
> exploitation of the Spectre variant 1 vulnerability.
>
> Fix this by sanitizing sl before using it to index ibp->sl_to_sc.
>
> 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://lore.kernel.org/lkml/[email protected]/
>
> Cc: [email protected]
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
> ---
Thanks, applied to for-rc.
--
Doug Ledford <[email protected]>
GPG KeyID: B826A3330E572FDD
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