This is a note to let you know that I've just added the patch titled
dm ioctl: fix out of bounds array access when no devices
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
dm-ioctl-fix-out-of-bounds-array-access-when-no-devices.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4edbe1d7bcffcd6269f3b5eb63f710393ff2ec7a Mon Sep 17 00:00:00 2001
From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Date: Fri, 26 Mar 2021 14:32:32 -0400
Subject: dm ioctl: fix out of bounds array access when no devices
From: Mikulas Patocka <mpatocka@xxxxxxxxxx>
commit 4edbe1d7bcffcd6269f3b5eb63f710393ff2ec7a upstream.
If there are not any dm devices, we need to zero the "dev" argument in
the first structure dm_name_list. However, this can cause out of
bounds write, because the "needed" variable is zero and len may be
less than eight.
Fix this bug by reporting DM_BUFFER_FULL_FLAG if the result buffer is
too small to hold the "nl->dev" value.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
[iwamatsu: Adjust context]
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-ioctl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -524,7 +524,7 @@ static int list_devices(struct dm_ioctl
* Grab our output buffer.
*/
nl = get_result_buffer(param, param_size, &len);
- if (len < needed) {
+ if (len < needed || len < sizeof(nl->dev)) {
param->flags |= DM_BUFFER_FULL_FLAG;
goto out;
}
Patches currently in stable-queue which might be from mpatocka@xxxxxxxxxx are
queue-4.9/dm-ioctl-fix-out-of-bounds-array-access-when-no-devices.patch
