blk-mq: protect debugfs_create_files() from failures

If debugfs were to return a non-NULL error for a debugfs call, using
that pointer later in debugfs_create_files() would crash.

Fix that by properly checking the pointer before referencing it.

Reported-by: Michal Hocko <mhocko@kernel.org>
Reported-and-tested-by: syzbot+b382ba6a802a3d242790@syzkaller.appspotmail.com
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Greg Kroah-Hartman 2019-01-23 14:48:54 +01:00
Родитель 2c1cf00eea
Коммит 36991ca68d
1 изменённых файлов: 3 добавлений и 0 удалений

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@ -838,6 +838,9 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_ctx_attrs[] = {
static bool debugfs_create_files(struct dentry *parent, void *data,
const struct blk_mq_debugfs_attr *attr)
{
if (IS_ERR_OR_NULL(parent))
return false;
d_inode(parent)->i_private = data;
for (; attr->name; attr++) {