{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64584","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T15:36:31.798Z","datePublished":"2026-08-06T07:06:25.953Z","dateUpdated":"2026-08-19T16:29:12.890Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-19T16:29:12.890Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_midi: cancel pending IN work before freeing the midi object\n\nThe f_midi driver embeds a work item (midi->work) whose handler,\nf_midi_in_work(), dereferences the enclosing struct f_midi through\ncontainer_of().  This work is armed from two sites: f_midi_complete(),\non a normal IN-endpoint completion, and f_midi_in_trigger(), on an ALSA\nrawmidi output-stream start.\n\nNeither f_midi_disable() nor f_midi_unbind() cancels midi->work.\nf_midi_disable() only disables the endpoints and drains the in_req_fifo;\nit does not synchronize the work item, and the sound card is released\nasynchronously to the final free of the midi object.\n\nThe midi object is reference-counted (midi->free_ref) and is freed in\nf_midi_free() only once both the usb_function reference and the rawmidi\nprivate_data reference have been dropped.  In f_midi_unbind(),\nf_midi_disable() runs before the sound card is released, so while the\nUSB endpoints are already disabled the rawmidi device is still usable by\nan open substream.  A concurrent userspace write on such a substream can\nreach f_midi_in_trigger() and queue midi->work again after\nf_midi_disable() has returned.  A work item armed this way may still be\npending when the last reference drops and f_midi_free() proceeds to\nkfree(midi), letting f_midi_in_work() dereference the struct after it\nhas been freed, a use-after-free.\n\nFor this reason cancelling midi->work in f_midi_disable() would not be\nsufficient: the ALSA trigger path can rearm the work after disable()\nreturns.  Cancelling at the refcount-zero free site is the boundary\nafter which neither arming source can survive, because by then both\nreferences that keep the midi object alive have been dropped: the USB\nendpoints are already disabled and the rawmidi device has been released.\n\nFix this by calling cancel_work_sync(&midi->work) in the refcount-zero\nblock of f_midi_free(), before the embedded work_struct is freed along\nwith the rest of the structure.  opts->lock is a sleeping mutex, so\ncalling cancel_work_sync() under it is permitted, and the handler takes\nmidi->transmit_lock rather than opts->lock, so no self-deadlock can\noccur while it waits for a running instance of the work to finish.\n\nThis issue was found by an in-house static analysis tool."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The UAF is reached by local configfs UDC clear or function unlink (unregister_gadget → f_midi_unbind/disable) plus ALSA rawmidi write/close on /dev/snd/midi*; no USB host traffic or cable access is required, and dummy_hcd suffices, matching other gadget teardown UAFs scored AV:L.\nAC:L - The attacker controls both sides of the race: opening/writing the rawmidi substream to queue midi->work via f_midi_in_trigger after disable, and forcing unbind plus dropping the last free_ref via configfs unlink/close, so the window is freely repeatable.\nPR:L - Exploitation needs access to the gadget configfs tree and/or the ALSA MIDI node; both are routinely delegated to non-root system/audio accounts on Android and embedded MIDI gadgets, with no capability check on the rawmidi write or UDC store path itself.\nUI:N - The attacker performs the full sequence—configfs unbind/unlink, rawmidi write to rearm work, and close to free the midi object—without any action by another user or administrator.\nS:U - The use-after-free corrupts kernel heap within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - f_midi_in_work() container_of()s the freed embedded work_struct and then reads midi->in_ep, fifo, and port/substream fields; reclaiming the freed f_midi slab yields a classic UAF read/disclosure primitive.\nI:H - Post-free f_midi_transmit()/f_midi_drop_out_substreams() write through the reclaimed object (port state, kfifo, snd_rawmidi_drop_output), giving a heap write-after-free primitive suitable for control-flow hijack.\nA:H - Dereferencing the freed f_midi from system_highpri_wq reliably produces KASAN reports, oops, or kernel panic even without full exploitation."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/f_midi.c"],"versions":[{"version":"3635523e9b96213969693c320302d536774d8e9b","lessThan":"f3c6f2c38062703d3dc7f86958bb0790c6959add","status":"affected","versionType":"git"},{"version":"8653d71ce3763aedcf3d2331f59beda3fecd79e4","lessThan":"df18150126f66817e4d3f79f309e9c92d6ff384e","status":"affected","versionType":"git"},{"version":"8653d71ce3763aedcf3d2331f59beda3fecd79e4","lessThan":"620955b222c47332297d6bf38f78541aa699238a","status":"affected","versionType":"git"},{"version":"8653d71ce3763aedcf3d2331f59beda3fecd79e4","lessThan":"380b4bef46c2eb260c7a9c6bb2c5be33ce5a38f9","status":"affected","versionType":"git"},{"version":"8653d71ce3763aedcf3d2331f59beda3fecd79e4","lessThan":"87bc316dd6fc90072297c635e10b9aa6075ecda1","status":"affected","versionType":"git"},{"version":"8653d71ce3763aedcf3d2331f59beda3fecd79e4","lessThan":"f45089eaad0a083d71d84ff175741d7e157d9b69","status":"affected","versionType":"git"},{"version":"8653d71ce3763aedcf3d2331f59beda3fecd79e4","lessThan":"ac9a51d910bb7465c554c45320cb6c09f3d0b49d","status":"affected","versionType":"git"},{"version":"8653d71ce3763aedcf3d2331f59beda3fecd79e4","lessThan":"5650c18d93a1db7e27cb5a40b394747eb4686d5b","status":"affected","versionType":"git"},{"version":"89019ab7a64fcdf98a2ba7799e5c6aff58d4a05d","status":"affected","versionType":"git"},{"version":"5.10.235","lessThan":"5.10.265","status":"affected","versionType":"semver"},{"version":"5.4.291","lessThan":"5.5","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/usb/gadget/function/f_midi.c"],"versions":[{"version":"5.12","status":"affected"},{"version":"0","lessThan":"5.12","status":"unaffected","versionType":"semver"},{"version":"5.10.265","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.216","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.183","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.148","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.101","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.42","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.6","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.235","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.12","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.291"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/f3c6f2c38062703d3dc7f86958bb0790c6959add"},{"url":"https://git.kernel.org/stable/c/df18150126f66817e4d3f79f309e9c92d6ff384e"},{"url":"https://git.kernel.org/stable/c/620955b222c47332297d6bf38f78541aa699238a"},{"url":"https://git.kernel.org/stable/c/380b4bef46c2eb260c7a9c6bb2c5be33ce5a38f9"},{"url":"https://git.kernel.org/stable/c/87bc316dd6fc90072297c635e10b9aa6075ecda1"},{"url":"https://git.kernel.org/stable/c/f45089eaad0a083d71d84ff175741d7e157d9b69"},{"url":"https://git.kernel.org/stable/c/ac9a51d910bb7465c554c45320cb6c09f3d0b49d"},{"url":"https://git.kernel.org/stable/c/5650c18d93a1db7e27cb5a40b394747eb4686d5b"}],"title":"usb: gadget: f_midi: cancel pending IN work before freeing the midi object","x_generator":{"engine":"bippy-1.2.0"}}}}