nvme: prevent potential spectre v1 gadget

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>
This commit is contained in:
Nitesh Shetty 2023-11-28 17:59:57 +05:30 committed by Keith Busch
parent 29ac4b2f92
commit 20dc66f2d7

View File

@ -18,6 +18,7 @@
#include <linux/nvme-keyring.h>
#include <crypto/hash.h>
#include <crypto/kpp.h>
#include <linux/nospec.h>
#include "nvmet.h"
@ -621,6 +622,7 @@ 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]--;
@ -1812,6 +1814,7 @@ 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);