Commit 36991ca6 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

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: default avatarMichal Hocko <mhocko@kernel.org>
Reported-and-tested-by: default avatar <syzbot+b382ba6a802a3d242790@syzkaller.appspotmail.com>
Reported-by: default avatarTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2c1cf00e

block/blk-mq-debugfs.c

+3 −0
Original line number Original line Diff line number Diff line
@@ -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,

static bool debugfs_create_files(struct dentry *parent, void *data,

				 const struct blk_mq_debugfs_attr *attr)

				 const struct blk_mq_debugfs_attr *attr)

{

{

	if (IS_ERR_OR_NULL(parent))

		return false;



	d_inode(parent)->i_private = data;

	d_inode(parent)->i_private = data;





	for (; attr->name; attr++) {

	for (; attr->name; attr++) {