From: Gustavo A. R. Silva gustavo@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.GY17484@dhcp22.suse.cz/
Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva gustavo@embeddedor.com Link: https://lore.kernel.org/r/20190731175428.GA16736@embeddedor Signed-off-by: Doug Ledford dledford@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@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" @@ -1536,6 +1537,7 @@ 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)