CVE-2026-64584

CVE CVE-2026-64584EUVD EUVD-2026-53771Veröffentlicht 2026-08-06T07:06:25.000ZZuletzt geändert 2026-08-08T15:13:21.000ZCVSS 7.8

Was das Advisory beschreibt

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_midi: cancel pending IN work before freeing the midi object The f_midi driver embeds a work item (midi->work) whose handler, f_midi_in_work(), dereferences the enclosing struct f_midi through container_of(). This work is armed from two sites: f_midi_complete(), on a normal IN-endpoint completion, and f_midi_in_trigger(), on an ALSA rawmidi output-stream start. Neither f_midi_disable() nor f_midi_unbind() cancels midi->work. f_midi_disable() only disables the endpoints and drains the in_req_fifo; it does not synchronize the work item, and the sound card is released asynchronously to the final free of the midi object. The midi object is reference-counted (midi->free_ref) and is freed in f_midi_free() only once both the usb_function reference and the rawmidi private_data reference have been dropped. In f_midi_unbind(), f_midi_disable() runs before the sound card is released, so while the USB endpoints are already disabled the rawmidi device is still usable by an open substream. A concurrent userspace write on such a substream can reach f_midi_in_trigger() and queue midi->work again after f_midi_disable() has returned. A work item armed this way may still be pending when the last reference drops and f_midi_free() proceeds to kfree(midi), letting f_midi_in_work() dereference the struct after it has been freed, a use-after-free. For this reason cancelling midi->work in f_midi_disable() would not be sufficient: the ALSA trigger path can rearm the work after disable() returns. Cancelling at the refcount-zero free site is the boundary after which neither arming source can survive, because by then both references that keep the midi object alive have been dropped: the USB endpoints are already disabled and the rawmidi device has been released. Fix this by calling cancel_work_sync(&midi->work) in the refcount-zero block of f_midi_free(), before the embedded work_struct is freed along with the rest of the structure. opts->lock is a sleeping mutex, so calling cancel_work_sync() under it is permitted, and the handler takes midi->transmit_lock rather than opts->lock, so no self-deadlock can occur while it waits for a running instance of the work to finish. This issue was found by an in-house static analysis tool.

Quelle: EUVD (ENISA), im Wortlaut der Meldung.

Produkte, die das Advisory nennt

Diese Angaben stammen aus der Meldung selbst, nicht aus einer Prüfung durch uns.

• Linux — Linux patch: 7.2-rc5; 8653d71ce3763aedcf3d2331f59beda3fecd79e4 <f45089eaad0a083d71d84ff175741d7e157d9b69; patch: 0; 8653d71ce3763aedcf3d2331f59beda3fecd79e4 <5650c18d93a1db7e27cb5a40b394747eb4686d5b; 3635523e9b96213969693c320302d536774d8e9b; patch: 6.12.101; 5.12; 5.4.291 <5.5; 89019ab7a64fcdf98a2ba7799e5c6aff58d4a05d; 8653d71ce3763aedcf3d2331f59beda3fecd79e4 <380b4bef46c2eb260c7a9c6bb2c5be33ce5a38f9; patch: 7.1.6; 5.10.235 <5.11; patch: 6.18.42; 8653d71ce3763aedcf3d2331f59beda3fecd79e4 <ac9a51d910bb7465c554c45320cb6c09f3d0b49d; patch: 6.6.148; 8653d71ce3763aedcf3d2331f59beda3fecd79e4 <87bc316dd6fc90072297c635e10b9aa6075ecda1

Die genannten Versionen sind die Angabe der Meldung. Patchlage vergleicht keine Versionsnummern und leitet aus ihnen keine Aussage ab — welche Version installiert ist, muss ein Mensch nachsehen.

Im Produktkatalog geführt

Für diese Produkte kann ein Bestand in Patchlage erfasst werden. Ein Advisory dazu erscheint am Morgen danach im Lagebericht.

• Linux — Linux

Patchlage meldet Treffer und Verdachtsfälle. Zu allem anderen sagt dieses System nichts — weder diese Seite noch der Lagebericht behauptet je, dass ein Bestand sicher ist.