{"id":"CVE-2026-64584","summary":"usb: gadget: f_midi: cancel pending IN work before freeing the midi object","details":"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-\u003ework) 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-\u003ework.\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-\u003efree_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-\u003ework 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-\u003ework 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-\u003ework) in the refcount-zero\nblock of f_midi_free(), before the embedded work_struct is freed along\nwith the rest of the structure.  opts-\u003elock is a sleeping mutex, so\ncalling cancel_work_sync() under it is permitted, and the handler takes\nmidi-\u003etransmit_lock rather than opts-\u003elock, 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.","modified":"2026-10-08T02:51:32.915376464Z","published":"2026-08-06T07:06:25.953Z","related":["SUSE-SU-2026:23477-1","SUSE-SU-2026:23481-1","SUSE-SU-2026:23528-1","SUSE-SU-2026:23529-1","SUSE-SU-2026:23881-1","SUSE-SU-2026:23887-1","SUSE-SU-2026:23897-1","SUSE-SU-2026:23902-1","SUSE-SU-2026:4120-1","SUSE-SU-2026:4254-1","openSUSE-SU-2026:11476-1","openSUSE-SU-2026:21910-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64584.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/380b4bef46c2eb260c7a9c6bb2c5be33ce5a38f9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5650c18d93a1db7e27cb5a40b394747eb4686d5b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/620955b222c47332297d6bf38f78541aa699238a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/87bc316dd6fc90072297c635e10b9aa6075ecda1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ac9a51d910bb7465c554c45320cb6c09f3d0b49d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/df18150126f66817e4d3f79f309e9c92d6ff384e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f3c6f2c38062703d3dc7f86958bb0790c6959add"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f45089eaad0a083d71d84ff175741d7e157d9b69"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64584.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64584"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3635523e9b96213969693c320302d536774d8e9b"},{"fixed":"f3c6f2c38062703d3dc7f86958bb0790c6959add"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8653d71ce3763aedcf3d2331f59beda3fecd79e4"},{"fixed":"df18150126f66817e4d3f79f309e9c92d6ff384e"},{"fixed":"620955b222c47332297d6bf38f78541aa699238a"},{"fixed":"380b4bef46c2eb260c7a9c6bb2c5be33ce5a38f9"},{"fixed":"87bc316dd6fc90072297c635e10b9aa6075ecda1"},{"fixed":"f45089eaad0a083d71d84ff175741d7e157d9b69"},{"fixed":"ac9a51d910bb7465c554c45320cb6c09f3d0b49d"},{"fixed":"5650c18d93a1db7e27cb5a40b394747eb4686d5b"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.10.235"},{"fixed":"5.10.265"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.4.291"},{"fixed":"5.5"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"89019ab7a64fcdf98a2ba7799e5c6aff58d4a05d"}]}],"versions":["v5.10.264","v5.10.263","v5.10.262","v5.10.261","v5.10.260","v5.10.259","v5.10.258","v5.10.257","v5.10.256","v5.10.255","v5.10.254","v5.10.253","v5.10.252","v5.10.251","v5.10.250","v5.10.249","v5.10.248","v5.10.247","v5.10.246","v5.10.245","v5.10.244","v5.10.243","v5.10.242","v5.10.241","v5.10.240","v5.10.239","v5.10.238","v5.10.237","v5.10.236","v5.10.235","v5.4.302","v5.4.301","v5.4.300","v5.4.299","v5.4.298","v5.4.297","v5.4.296","v5.4.295","v5.4.294","v5.4.293","v5.4.292","v5.4.291"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64584.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.10.265"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.216"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.12.0"},{"fixed":"6.1.183"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.6.148"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.12.101"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.18.42"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"7.1.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64584.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}