[PATCH AUTOSEL 6.6 33/47] nvme: prevent potential spectre v1 gadget

Sasha Levin
2023-12-11T13:54:51Z

From: Nitesh Shetty <nj.shetty@samsung.com>

[ Upstream commit 20dc66f2d76b4a410df14e4675e373b718babc34 ]

This patch fixes the smatch warning, "nvmet_ns_ana_grpid_store() warn:
potential spectre issue 'nvmet_ana_group_enabled' [w] (local cap)"
Prevent the contents of kernel memory from being leaked to user space
via speculative execution by using array_index_nospec.

Signed-off-by: Nitesh Shetty <nj.shetty@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/target/configfs.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 907143870da52..01b2a3d1a5e6c 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -17,6 +17,7 @@
#endif
#include <crypto/hash.h>
#include <crypto/kpp.h>
+#include <linux/nospec.h>

#include "nvmet.h"

@@ -509,6 +510,7 @@ static ssize_t nvmet_ns_ana_grpid_store(struct config_item *item,

down_write(&nvmet_ana_sem);
oldgrpid = ns->anagrpid;
+ newgrpid = array_index_nospec(newgrpid, NVMET_MAX_ANAGRPS);
nvmet_ana_group_enabled[newgrpid]++;
ns->anagrpid = newgrpid;
nvmet_ana_group_enabled[oldgrpid]--;
@@ -1700,6 +1702,7 @@ static struct config_group *nvmet_ana_groups_make_group(
grp->grpid = grpid;

down_write(&nvmet_ana_sem);
+ grpid = array_index_nospec(grpid, NVMET_MAX_ANAGRPS);
nvmet_ana_group_enabled[grpid]++;
up_write(&nvmet_ana_sem);

--
2.42.0