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authorJordy Zomer <jordy@jordyzomer.github.io>2022-01-29 17:58:39 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-13 21:59:05 +0300
commit02cc46f397eb3691c56affbd5073e54f7a82ac32 (patch)
tree77484f6161dde9fa65def0466bf0fb166681c656 /drivers/md
parent049072749a5e1fe277ee64746bbe9fca5c55f3f9 (diff)
downloadlinux-02cc46f397eb3691c56affbd5073e54f7a82ac32.tar.xz
dm ioctl: prevent potential spectre v1 gadget
[ Upstream commit cd9c88da171a62c4b0f1c70e50c75845969fbc18 ] It appears like cmd could be a Spectre v1 gadget as it's supplied by a user and used as an array index. Prevent the contents of kernel memory from being leaked to userspace via speculative execution by using array_index_nospec. Signed-off-by: Jordy Zomer <jordy@pwning.systems> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/dm-ioctl.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 21fe8652b095..901abd6dea41 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -18,6 +18,7 @@
#include <linux/dm-ioctl.h>
#include <linux/hdreg.h>
#include <linux/compat.h>
+#include <linux/nospec.h>
#include <linux/uaccess.h>
#include <linux/ima.h>
@@ -1788,6 +1789,7 @@ static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
return NULL;
+ cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls));
*ioctl_flags = _ioctls[cmd].flags;
return _ioctls[cmd].fn;
}