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authorMikulas Patocka <mpatocka@redhat.com>2021-03-26 21:32:32 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-03-30 15:40:10 +0300
commitba73e621ced58ff4ad1020a140ccb5843da1cb26 (patch)
tree67e43616c19db9f1d77576b68c34d20ac13eab5c /drivers
parente110c8a8d921dae7011e88ed5cb30c35bef88cd7 (diff)
downloadlinux-ba73e621ced58ff4ad1020a140ccb5843da1cb26.tar.xz
dm ioctl: fix out of bounds array access when no devices
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@redhat.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/md/dm-ioctl.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 469453e106d1..2f020401d5ba 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -529,7 +529,7 @@ static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_
* Grab our output buffer.
*/
nl = orig_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;
}