Re: ath9k broken [was: Linux 5.7.3]

[Gabriel C <nix.or.die@googlemail.com>]

Am Do., 25. Juni 2020 um 06:57 Uhr schrieb Jiri Slaby <jirislaby@kernel.org>:
>
> On 25. 06. 20, 0:05, Gabriel C wrote:
> > Am Mi., 17. Juni 2020 um 18:13 Uhr schrieb Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org>:
> >>
> >> I'm announcing the release of the 5.7.3 kernel.
> >>
> >
> > Hello Greg,
> >
> >> Qiujun Huang (5):
> >>       ath9k: Fix use-after-free Read in htc_connect_service
> >>       ath9k: Fix use-after-free Read in ath9k_wmi_ctrl_rx
> >>       ath9k: Fix use-after-free Write in ath9k_htc_rx_msg
> >>       ath9x: Fix stack-out-of-bounds Write in ath9k_hif_usb_rx_cb
> >>       ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb
> >>
> >
> > We got a report on IRC about 5.7.3+ breaking a USB ath9k Wifi Dongle,
> > while working fine on <5.7.3.
> >
> > I don't have myself such HW, and the reported doesn't have any experience
> > in bisecting the kernel, so we build kernels, each with one of the
> > above commits reverted,
> > to find the bad commit.
> >
> > The winner is:
> >
> > commit 6602f080cb28745259e2fab1a4cf55eeb5894f93
> > Author: Qiujun Huang <hqjagain@gmail.com>
> > Date:   Sat Apr 4 12:18:38 2020 +0800
> >
> >     ath9k: Fix general protection fault in ath9k_hif_usb_rx_cb
> >
> >     commit 2bbcaaee1fcbd83272e29f31e2bb7e70d8c49e05 upstream.
> > ...
> >
> > Reverting this one fixed his problem.
>
> Obvious question: is 5.8-rc1 (containing the commit) broken too?

Yes, it does, just checked.

git tag --contains 2bbcaaee1fcbd83272e29f31e2bb7e70d8c49e05
v5.8-rc1
v5.8-rc2

>
> I fail to see how the commit could cause an issue like this. Is this
> really reproducibly broken with the commit and irreproducible without
> it?

I can't see something obvious wrong either, but yes it's reproducible on his HW.
Kernel with this commit breaks the dongle, with the commit reverted it works.

>As it looks like a USB/wiring problem:
> usb 1-2: USB disconnect, device number 2
> ath: phy0: Reading Magic # failed
> ath: phy0: Unable to initialize hardware; initialization status: -5
> ...
> usb 1-2: device descriptor read/64, error -110
> usb 1-2: device descriptor read/64, error -71
>
> Ccing ath9k maintainers too.
>
> > I don't have so much info about the HW, besides a dmesg showing the
> > phy breaking.
> > I also added the reporter to CC too.
> >
> > https://gist.github.com/AngryPenguinPL/1e545f0da3c2339e443b9e5044fcccea
> >
> > If you need more info, please let me know and I'll try my best to get
> > it as fast as possible for you.
>

Best Regards,

Gabriel C