From: Gustavo A. R. Silva <gust...@embeddedor.com> commit 6497d0a9c53df6e98b25e2b79f2295d7caa47b6e upstream.
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/20180423164740.gy17...@dhcp22.suse.cz/ Cc: sta...@vger.kernel.org Signed-off-by: Gustavo A. R. Silva <gust...@embeddedor.com> Link: https://lore.kernel.org/r/20190731175428.GA16736@embeddedor Signed-off-by: Doug Ledford <dledf...@redhat.com> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/infiniband/hw/hfi1/verbs.c | 2 ++ 1 file changed, 2 insertions(+) --- 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" @@ -1587,6 +1588,7 @@ static int hfi1_check_ah(struct ib_devic 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)
