Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

HID: sony: fix UAF of ghl_poke_timer / ghl_urb at driver unbind

For GHL (Guitar Hero Live) dongles, sony_probe() arms a periodic timer: ghl_magic_poke() (the timer callback) submits sc->ghl_urb, and the URB completion ghl_magic_poke_cb() re-arms the timer with mod_timer().

sony_remove() drained the timer with timer_delete_sync() and then freed the URB with usb_free_urb():

timer_delete_sync(&sc->ghl_poke_timer); usb_free_urb(sc->ghl_urb);

timer_delete_sync() does not block re-arming, and while the URB is in flight the timer is not pending, so the sync delete is a no-op. A URB completion that runs after the delete re-arms the timer, and usb_free_urb() only drops a reference -- it does not kill an in-flight URB. sc is allocated with devm_kzalloc() and freed once sony_remove() returns, so the re-armed ghl_poke_timer (embedded in sc) then fires on freed memory, a use-after-free from timer softirq. This is a disconnect/rmmod race.

Poison the URB first, then shut the timer down, before freeing the URB. usb_poison_urb() kills any in-flight URB and permanently rejects further submissions, so a poke timer that is still pending cannot re-submit the URB from ghl_magic_poke() in the window before timer_shutdown_sync() runs. usb_kill_urb() would not suffice: it only cancels the in-flight URB and leaves it submittable once it returns, so the pending timer could re-submit it and put a fresh URB in flight over the fr…

In the Linux kernel, the following vulnerability has been resolved:

HID: sony: fix UAF of ghl_poke_timer / ghl_urb at driver unbind

For GHL (Guitar Hero Live) dongles, sony_probe() arms a periodic timer: ghl_magic_poke() (the timer callback) submits sc->ghl_urb, and the URB completion ghl_magic_poke_cb() re-arms the timer with mod_timer().

sony_remove() drained the timer with timer_delete_sync() and then freed the URB with usb_free_urb():

timer_delete_sync(&sc->ghl_poke_timer); usb_free_urb(sc->ghl_urb);

timer_delete_sync() does not block re-arming, and while the URB is in flight the timer is not pending, so the sync delete is a no-op. A URB completion that runs after the delete re-arms the timer, and usb_free_urb() only drops a reference -- it does not kill an in-flight URB. sc is allocated with devm_kzalloc() and freed once sony_remove() returns, so the re-armed ghl_poke_timer (embedded in sc) then fires on freed memory, a use-after-free from timer softirq. This is a disconnect/rmmod race.

Poison the URB first, then shut the timer down, before freeing the URB. usb_poison_urb() kills any in-flight URB and permanently rejects further submissions, so a poke timer that is still pending cannot re-submit the URB from ghl_magic_poke() in the window before timer_shutdown_sync() runs. usb_kill_urb() would not suffice: it only cancels the in-flight URB and leaves it submittable once it returns, so the pending timer could re-submit it and put a fresh URB in flight over the fr…

kernel-devel-7.2.7-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 193 more

In the Linux kernel, the following vulnerability has been resolved: HID: sony: fix UAF of ghl_poke_timer / ghl_urb at driver unbind For GHL (Guitar Hero Live) dongles, sony_probe() arms a periodic timer: ghl_magic_poke() (the timer callback) submits sc->ghl_urb, and the URB completion ghl_magic_poke_cb() re-arms the timer with mod_timer(). sony_remove() drained the timer with timer_delete_sync() and then freed the URB with usb_free_urb(): timer_delete_sync(&sc->ghl_poke_timer); usb_free_urb(sc->ghl_urb); timer_delete_sync() does not block re-arming, and while the URB is in flight the timer is not pending, so the sync delete is a no-op. A URB completion that runs after the delete re-arms the timer, and usb_free_urb() only drops a reference -- it does not kill an in-flight URB. sc is allocated with devm_kzalloc() and freed once sony_remove() returns, so the re-armed ghl_poke_timer (embedded in sc) then fires on freed memory, a use-after-free from timer softirq. This is a disconnect/rmmod race. Poison the URB first, then shut the timer down, before freeing the URB. usb_poison_urb() kills any in-flight URB and permanently rejects further submissions, so a poke timer that is still pending cannot re-submit the URB from ghl_magic_poke() in the window before timer_shutdown_sync() runs. usb_kill_urb() would not suffice: it only cancels the in-flight URB and leaves it submittable once it returns, so the pending timer could re-submit it and put a fresh URB in flight over the freed sc…

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um Sicherheitsmaßnahmen zu umgehen, Daten oder den Systemzustand zu manipulieren, Denial-of-Service-Zustände herbeizuführen oder andere, nicht näher spezifizierte Angriffe durchzuführen.