On Thu, Jan 31, 2019 at 08:29:37PM +0900, Tetsuo Handa wrote: > On 2019/01/31 19:51, Greg KH wrote: > > Can you test the patch below? > > You can ask syzbot to test the patch. But > > > @@ -461,7 +463,7 @@ static struct rchan_buf *relay_open_buf(struct rchan > > *chan, unsigned int cpu) > > dentry = chan->cb->create_buf_file(NULL, NULL, > > S_IRUSR, buf, > > &chan->is_global); > > - if (WARN_ON(dentry)) > > + if (IS_ERR_OR_NULL(dentry)) > > goto free_buf; > > are you trying to fix a different bug together that old code was by error > bailing > out when chan->cb->create_buf_file() returned a valid "struct dentry *" ? > I don't know what WARN_ON() due to a valid "struct dentry *" means...
I don't either, I'm guessing that's a code path that has never been taken, or everyone just ignores it :) Anyway, I fixed it up to be safe. And the reproducer shows it now works properly too. thanks, greg k-h
