From: Tony Luck <tony.luck@intel.com>
To: Doug Ledford <dledford@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>, Jason Gunthorpe <jgg@ziepe.ca>,
Leon Romanovsky <leon@kernel.org>,
Parav Pandit <parav@mellanox.com>,
Ira Weiny <ira.weiny@intel.com>,
linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] IB/core: Add mitigation for Spectre V1
Date: Tue, 30 Jul 2019 13:24:07 -0700 [thread overview]
Message-ID: <20190730202407.31046-1-tony.luck@intel.com> (raw)
Some processors may mispredict an array bounds check and
speculatively access memory that they should not. With
a user supplied array index we like to play things safe
by masking the value with the array size before it is
used as an index.
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
[I don't have h/w, so just compile tested]
drivers/infiniband/core/user_mad.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 9f8a48016b41..fdce254e4f65 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -49,6 +49,7 @@
#include <linux/sched.h>
#include <linux/semaphore.h>
#include <linux/slab.h>
+#include <linux/nospec.h>
#include <linux/uaccess.h>
@@ -888,6 +889,7 @@ static int ib_umad_unreg_agent(struct ib_umad_file *file, u32 __user *arg)
mutex_lock(&file->port->file_mutex);
mutex_lock(&file->mutex);
+ id = array_index_nospec(id, IB_UMAD_MAX_AGENTS);
if (id >= IB_UMAD_MAX_AGENTS || !__get_agent(file, id)) {
ret = -EINVAL;
goto out;
--
2.20.1
next reply other threads:[~2019-07-30 20:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-30 20:24 Tony Luck [this message]
2019-07-30 23:34 ` [PATCH] IB/core: Add mitigation for Spectre V1 Ira Weiny
2019-07-30 23:52 ` Gustavo A. R. Silva
2019-07-31 4:28 ` Ira Weiny
2019-07-31 4:39 ` [PATCH V2] " Luck, Tony
2019-07-31 14:52 ` Doug Ledford
2019-07-31 17:52 ` Gustavo A. R. Silva
2019-07-31 18:52 ` Doug Ledford
2019-07-31 19:22 ` Doug Ledford
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