On Tue, Sep 25, 2018 at 5:15 PM, Alan Stern stern@rowland.harvard.edu wrote:
On Tue, 25 Sep 2018, Vladis Dronov wrote:
What reason is there for having two different fixes for the same bug? This one isn't going to get into any mainline trees that don't already have c9a4cb204e9e.
I believe this is the right thing to do, so usb_find_alt_setting() is not called with a known-bad argument.
Honestly, I would change "if (!config)" in usb_find_alt_setting() to "BUG_ON(!config)" so we know when its callers do smth wrong and go
(You'll be lucky if Linus doesn't see that. He yells at anybody who suggests adding BUG_ON for anything that doesn't completely crash the kernel. The basic problem is that "BUG_ON" is not a good name: That routine doesn't really report bugs; instead it brings everything to a halt in situations where the kernel is unable to proceed. In practice this tends to make actual debugging more difficult.)
What about adding a WARN_ON()? It doesn't crash the kernel and it will be detected and reported by syzbot.