From: Greg Kroah-Hartman <gre...@linuxfoundation.org> [ Upstream commit 36991ca68db9dd43bac7f3519f080ee3939263ef ]
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 <mho...@kernel.org> Reported-and-tested-by: syzbot+b382ba6a802a3d242...@syzkaller.appspotmail.com Reported-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> Signed-off-by: Sasha Levin <sas...@kernel.org> --- block/blk-mq-debugfs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index d95439154556..da0453277f7f 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -791,6 +791,9 @@ 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++) { -- 2.19.1