Re: Linux 4.2-rc1

[Linus Torvalds]

On Wed, Jul 8, 2015 at 10:17 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> Decoding the "Code:" line shows that this is the "->fw_id" dereference in
>
>         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
>                 return -ENOMEM;
>
> and that "fw_priv->buf" pointer is NULL.
>
> However, I don't see anything that looks like it should have changed
> any of this since 4.1.

Looking at the otehr uses of "fw_priv->buf", they all check that
pointer for NULL. I see code like

        fw_buf = fw_priv->buf;
        if (!fw_buf)
                goto out;

etc.

Also, it looks like you need to hold the "fw_lock" to even look at
that pointer, since the buffer can get reallocated etc.

So that uevent code really looks buggy. It just doesn't look like a
*new* bug to me. That code looks old, going back to 2012 and commit
1244691c73b2.

Ming Lei?

                 Linus
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