{"id":"CVE-2026-90207","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-90207","summary":"ALSA: seq: midi: Serialize input teardown with event_input","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: seq: midi: Serialize input teardown with event_input\n\nsnd_midi_input_event() must not be running while a rawmidi substream is\nclosing, since this can lead to the trigger state becoming out-of-step\nthrough this sequence in snd_rawmidi_input_trigger():\n\n\tsnd_rawmidi_input_trigger(up=0)\n\t\t\t\t\tsnd_midi_input_event()\n\t\t\t\t\t -> snd_rawmidi_kernel_read()\n\t\t\t\t\t     -> snd_rawmidi_input_trigger(up=1)\n\t  -> cancel_work_sync()\n\nwhich ends with the underlying device being active unexpectedly.\n\nWhen this is called from close_substream(), further input can re-trigger\nthe input event leaving it running after rawmidi_release_priv() has set\nrfile->rmidi to NULL which leads to:\n\n\tUnable to handle kernel NULL pointer dereference at virtual address 00000000000000b0\n\tCall trace:\n\t snd_midi_input_event+0x3c/0x134 [snd_seq_midi] (P)\n\t snd_rawmidi_input_event_work+0x1c/0x2c\n\t process_one_work+0x150/0x3a4\n\t worker_thread+0x190/0x318\n\nApply a similar approach to commit ef7607ab1c8ad (\"ALSA: seq: midi:\nSerialize output teardown with event_input\") which fixed the same issue\nin the output direction, but updated to use RCU following Takashi Iwai's\nproposed follow-on patch [1].\n\nWith this change in place, midisynth_unsubscribe() clears the input file\nso snd_midi_input_event() will not re-trigger the stream and will be\nquiesced by the cancel_work_sync() in snd_rawmidi_input_trigger().\n\n[1] https://lore.kernel.org/linux-sound/20260813144224.753399-1-tiwai@suse.de/","published":"2026-09-17T16:07:22.825Z","modified":"2026-09-19T03:47:25.570424850Z","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.1.188"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/210c193a9ef1312fab153948c6928e4cfaa1f03b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/282a3ef9e4b63b2f6823bbbb3c1a90b002cdaf12"},{"type":"WEB","url":"https://git.kernel.org/stable/c/403f7f3ad3808a0096d84cf228fab68dc253fd9d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6290afaae54c7a9fa3bca3b4d5433e6d83e8669d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/89d986897aff7275b42e075e556731b8353366af"},{"type":"WEB","url":"https://git.kernel.org/stable/c/de76a2b47582cd6dba2e15f024681bf377ecc94a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90207.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90207"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-19T03:47:25.570424850Z"}}