CVE-2026-90207
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: ALSA: seq: midi: Serialize input teardown with event_input snd_midi_input_event() must not be running while a rawmidi substream is closing, since this can lead to the trigger state becoming out-of-step through this sequence in snd_rawmidi_input_trigger(): snd_rawmidi_input_trigger(up=0) snd_midi_input_event() -> snd_rawmidi_kernel_read() -> snd_rawmidi_input_trigger(up=1) -> cancel_work_sync() which ends with the underlying device being active unexpectedly. When this is called from close_substream(), further input can re-trigger the input event leaving it running after rawmidi_release_priv() has set rfile->rmidi to NULL which leads to: Unable to handle kernel NULL pointer dereference at virtual address 00000000000000b0 Call trace: snd_midi_input_event+0x3c/0x134 [snd_seq_midi] (P) snd_rawmidi_input_event_work+0x1c/0x2c process_one_work+0x150/0x3a4 worker_thread+0x190/0x318 Apply a similar approach to commit ef7607ab1c8ad ("ALSA: seq: midi: Serialize output teardown with event_input") which fixed the same issue in the output direction, but updated to use RCU following Takashi Iwai's proposed follow-on patch [1]. With this change in place, midisynth_unsubscribe() clears the input file so snd_midi_input_event() will not re-trigger the stream and will be quiesced by the cancel_work_sync() in snd_rawmidi_input_trigger(). [1] https://lore.kernel.org/linux-sound/20260813144224.753399-1-tiwai@suse.de/
Gravité et risque d'exploitation
CVE-2026-90207 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.16 %, ce qui la place devant 5.3 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <=6.1.*, <=6.12.*, 2.6.12, 0, 6.1.188, 6.18.52, <2.6.12, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, <=6.6.*, <89d986897aff7275b42e075e556731b8353366af, 6.6.157, 7.2.6, <=6.18.*, <6290afaae54c7a9fa3bca3b4d5433e6d83e8669d, <de76a2b47582cd6dba2e15f024681bf377ecc94a, 6.12.110, <=7.2.*, <=*, <210c193a9ef1312fab153948c6928e4cfaa1f03b, <282a3ef9e4b63b2f6823bbbb3c1a90b002cdaf12, <403f7f3ad3808a0096d84cf228fab68dc253fd9d, 7.3) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://git.kernel.org/stable/c/de76a2b47582cd6dba2e15f024681bf377ecc94a
- https://git.kernel.org/stable/c/89d986897aff7275b42e075e556731b8353366af
- https://git.kernel.org/stable/c/6290afaae54c7a9fa3bca3b4d5433e6d83e8669d
- https://git.kernel.org/stable/c/210c193a9ef1312fab153948c6928e4cfaa1f03b
- https://git.kernel.org/stable/c/282a3ef9e4b63b2f6823bbbb3c1a90b002cdaf12
- https://git.kernel.org/stable/c/403f7f3ad3808a0096d84cf228fab68dc253fd9d
