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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: "Luck, Tony" <tony.luck@intel.com>,
	Doug Ledford <dledford@redhat.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-rdma@vger.kernel.org
Subject: [PATCH AUTOSEL 4.4 11/14] IB/core: Add mitigation for Spectre V1
Date: Tue,  6 Aug 2019 17:37:45 -0400	[thread overview]
Message-ID: <20190806213749.20689-11-sashal@kernel.org> (raw)
In-Reply-To: <20190806213749.20689-1-sashal@kernel.org>

From: "Luck, Tony" <tony.luck@intel.com>

[ Upstream commit 61f259821dd3306e49b7d42a3f90fb5a4ff3351b ]

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>
Link: https://lore.kernel.org/r/20190731043957.GA1600@agluck-desk2.amr.corp.intel.com
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/core/user_mad.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 57f281f8d6862..e9e75f40714cb 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 <asm/uaccess.h>
 
@@ -842,11 +843,14 @@ static int ib_umad_unreg_agent(struct ib_umad_file *file, u32 __user *arg)
 
 	if (get_user(id, arg))
 		return -EFAULT;
+	if (id >= IB_UMAD_MAX_AGENTS)
+		return -EINVAL;
 
 	mutex_lock(&file->port->file_mutex);
 	mutex_lock(&file->mutex);
 
-	if (id >= IB_UMAD_MAX_AGENTS || !__get_agent(file, id)) {
+	id = array_index_nospec(id, IB_UMAD_MAX_AGENTS);
+	if (!__get_agent(file, id)) {
 		ret = -EINVAL;
 		goto out;
 	}
-- 
2.20.1


  parent reply	other threads:[~2019-08-06 21:38 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-06 21:37 [PATCH AUTOSEL 4.4 01/14] xtensa: fix build for cores with coprocessors Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 02/14] xen/pciback: remove set but not used variable 'old_state' Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 03/14] irqchip/irq-imx-gpcv2: Forward irq type to parent Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 04/14] perf header: Fix divide by zero error if f_header.attr_size==0 Sasha Levin
2019-08-19 12:07   ` Jack Wang
2019-08-19 14:15     ` Jiri Olsa
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 05/14] perf header: Fix use of unitialized value warning Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 06/14] libata: zpodd: Fix small read overflow in zpodd_get_mech_type() Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 07/14] scsi: hpsa: correct scsi command status issue after reset Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 08/14] exit: make setting exit_state consistent Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 09/14] ata: libahci: do not complain in case of deferred probe Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 10/14] kbuild: modpost: handle KBUILD_EXTRA_SYMBOLS only for external modules Sasha Levin
2019-08-06 21:37 ` Sasha Levin [this message]
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 12/14] ocfs2: remove set but not used variable 'last_hash' Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 13/14] coredump: split pipe command whitespace before expanding template Sasha Levin
2019-08-06 21:37 ` [PATCH AUTOSEL 4.4 14/14] asm-generic: fix -Wtype-limits compiler warnings Sasha Levin
2019-08-19 16:53 ` [PATCH AUTOSEL 4.4 01/14] xtensa: fix build for cores with coprocessors Ben Hutchings
2019-08-19 17:06   ` Max Filippov

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