{"id":"CVE-2026-74501","state":"PUBLISHED","title":"ALSA: usb-audio: fix use-after-free in ump_to_endpoint()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: usb-audio: fix use-after-free in ump_to_endpoint()\n\ncreate_midi2_ump() registers a card-owned snd_ump_endpoint and stores a\nback-pointer to its per-interface snd_usb_midi2_ump object in\nump->private_data, but it never installs an ump->private_free hook and\nnever clears that pointer.\n\nIf a later step of snd_usb_midi_v2_create() fails, its error path calls\nfree_all_midi2_umps(), which kfree()s the snd_usb_midi2_ump object while\nthe already-registered endpoint keeps pointing at it.  The created\n/dev/snd/umpC*D* node stays exposed, so the first operation of any UMP\nopen, ump_to_endpoint(), dereferences the dangling ump->private_data and\nreads rmidi->eps[dir] out of freed memory.\n\nA malicious USB MIDI 2.0 device that makes creation fail after the\nendpoint is registered can thus trigger a slab use-after-free read on a\nsubsequent open of the UMP node.\n\nClear the endpoint's back-pointer before freeing the object, and let\nump_to_endpoint() tolerate a NULL private_data so the open/close/trigger\ncallbacks fail cleanly (their callers already handle a NULL endpoint)\ninstead of dereferencing a stale pointer.\n\nDiscovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>","publishedAt":"2026-08-15T12:27:26.957Z","updatedAt":"2026-08-17T05:20:39.729Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"49eccef6d6e1c00dac6fb2e7eb6f9206c33e1c37","versionType":"git"},{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"8a7a33b846d6ba695891b8d0040027cdbad8cd52","versionType":"git"},{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"cc014ebf803174f0e5d15956dfc5a38413c945ae","versionType":"git"},{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"ae388c0e1bf727972096f770f82d12e4f748d1b6","versionType":"git"},{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"4a05b2d1b4642df74f30b6f54843e825c4a2bfd3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/midi2.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.5","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/midi2.c"]}],"references":["https://git.kernel.org/stable/c/49eccef6d6e1c00dac6fb2e7eb6f9206c33e1c37","https://git.kernel.org/stable/c/8a7a33b846d6ba695891b8d0040027cdbad8cd52","https://git.kernel.org/stable/c/cc014ebf803174f0e5d15956dfc5a38413c945ae","https://git.kernel.org/stable/c/ae388c0e1bf727972096f770f82d12e4f748d1b6","https://git.kernel.org/stable/c/4a05b2d1b4642df74f30b6f54843e825c4a2bfd3"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74501.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74501","state":"PUBLISHED","datePublished":"2026-08-15T12:27:26.957Z","dateUpdated":"2026-08-17T05:20:39.729Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.907Z"},"containers":{"cna":{"title":"ALSA: usb-audio: fix use-after-free in ump_to_endpoint()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: usb-audio: fix use-after-free in ump_to_endpoint()\n\ncreate_midi2_ump() registers a card-owned snd_ump_endpoint and stores a\nback-pointer to its per-interface snd_usb_midi2_ump object in\nump->private_data, but it never installs an ump->private_free hook and\nnever clears that pointer.\n\nIf a later step of snd_usb_midi_v2_create() fails, its error path calls\nfree_all_midi2_umps(), which kfree()s the snd_usb_midi2_ump object while\nthe already-registered endpoint keeps pointing at it.  The created\n/dev/snd/umpC*D* node stays exposed, so the first operation of any UMP\nopen, ump_to_endpoint(), dereferences the dangling ump->private_data and\nreads rmidi->eps[dir] out of freed memory.\n\nA malicious USB MIDI 2.0 device that makes creation fail after the\nendpoint is registered can thus trigger a slab use-after-free read on a\nsubsequent open of the UMP node.\n\nClear the endpoint's back-pointer before freeing the object, and let\nump_to_endpoint() tolerate a NULL private_data so the open/close/trigger\ncallbacks fail cleanly (their callers already handle a NULL endpoint)\ninstead of dereferencing a stale pointer.\n\nDiscovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"49eccef6d6e1c00dac6fb2e7eb6f9206c33e1c37","versionType":"git"},{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"8a7a33b846d6ba695891b8d0040027cdbad8cd52","versionType":"git"},{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"cc014ebf803174f0e5d15956dfc5a38413c945ae","versionType":"git"},{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"ae388c0e1bf727972096f770f82d12e4f748d1b6","versionType":"git"},{"version":"ff49d1df79aef7580fe3ac99d17c3f886655d080","status":"affected","lessThan":"4a05b2d1b4642df74f30b6f54843e825c4a2bfd3","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/midi2.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.5","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.8","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/midi2.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/49eccef6d6e1c00dac6fb2e7eb6f9206c33e1c37"},{"url":"https://git.kernel.org/stable/c/8a7a33b846d6ba695891b8d0040027cdbad8cd52"},{"url":"https://git.kernel.org/stable/c/cc014ebf803174f0e5d15956dfc5a38413c945ae"},{"url":"https://git.kernel.org/stable/c/ae388c0e1bf727972096f770f82d12e4f748d1b6"},{"url":"https://git.kernel.org/stable/c/4a05b2d1b4642df74f30b6f54843e825c4a2bfd3"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:20:39.729Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.6.151"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.12.103"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"6.18.44"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.1.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}