Commit 6497d0a9 authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Doug Ledford
Browse files

IB/hfi1: Fix Spectre v1 vulnerability 

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: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
Link: https://lore.kernel.org/r/20190731175428.GA16736@embeddedor


Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 770b7d96

drivers/infiniband/hw/hfi1/verbs.c

+2 −0
Original line number Diff line number Diff line
@@ -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_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)