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authorLuck, Tony <tony.luck@intel.com>2019-07-30 21:39:57 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-08-25 10:53:00 +0200
commitb88f8f192e2b7582d62c5176caf31cc6bf3355cc (patch)
treeece6008e8b94b0090e8469f18c119a6dfa106309
parent81882762061b93890ca50d975cb90ee61ccab194 (diff)
IB/core: Add mitigation for Spectre V1
[ 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>
-rw-r--r--drivers/infiniband/core/user_mad.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 57f281f8d686..e9e75f40714c 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;
}