{"schema":"threatline.record/2","record":{"id":"CVE-2026-98764","aliases":[],"summary":"usb: gadget: f_fs: Fix NULL pointer dereference in FUNCTIONFS_ENDPOINT_DESC","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_fs: Fix NULL pointer dereference in FUNCTIONFS_ENDPOINT_DESC\n\nWhen user space sets up FunctionFS with only full-speed descriptors\n(e.g., flags = FUNCTIONFS_HAS_FS_DESC) and the gadget operates at a\nhigher speed (such as USB_SPEED_HIGH or USB_SPEED_SUPER),\nconfig_ep_by_speed() detects that the function lacks descriptors for\nthe current speed, logs a warning, and falls back to full-speed\ndescriptors. The endpoint is then successfully enabled via\nusb_ep_enable(), and epfile->ep becomes valid.\n\nHowever, when user space subsequently issues the FUNCTIONFS_ENDPOINT_DESC\nioctl to query the endpoint descriptor, ffs_epfile_ioctl() selects the\ndescriptor index solely based on gadget->speed:\n\n\tswitch (epfile->ffs->gadget->speed) {\n\tcase USB_SPEED_SUPER:\n\tcase USB_SPEED_SUPER_PLUS:\n\t\tdesc_idx = 2;\n\t\tbreak;\n\tcase USB_SPEED_HIGH:\n\t\tdesc_idx = 1;\n\t\tbreak;\n\tdefault:\n\t\tdesc_idx = 0;\n\t}\n\tdesc = epfile->ep->descs[desc_idx];\n\tmemcpy(&desc1, desc, desc->bLength);\n\nBecause user space only supplied full-speed descriptors,\nepfile->ep->descs[1] is NULL. Dereferencing desc->bLength triggers an\nimmediate kernel NULL pointer dereference panic.\n\nFix this by falling back through lower speed descriptors if the current\nspeed descriptor was not supplied, matching the fallback logic in\nconfig_ep_by_speed() and historical f_fs behavior. If still missing,\nfall back to epfile->ep->ep->desc (the active descriptor), and return\n-EINVAL safely if no valid descriptor is found. In addition, mark desc\nas const to match struct usb_ep::desc and avoid discarding qualifiers.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98764","source_modified_at":"2026-10-21T12:56:38.602Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"c559a353410939c0884e83bdb0e2420a986ac53b","lessThan":"06ac8609d6d185ac18c1d6a6a8a9b99e398bd124","status":"affected","versionType":"git"},{"version":"c559a353410939c0884e83bdb0e2420a986ac53b","lessThan":"9d8761b3c133f6c6a6d3486839dac60e2cf4bfe3","status":"affected","versionType":"git"},{"version":"c559a353410939c0884e83bdb0e2420a986ac53b","lessThan":"7811d8e26c77f8eea79e22d0d14c67ec0658b348","status":"affected","versionType":"git"},{"version":"c559a353410939c0884e83bdb0e2420a986ac53b","lessThan":"35ab269602e1f7c4c0fe6ea3477264bea77eced3","status":"affected","versionType":"git"},{"version":"c559a353410939c0884e83bdb0e2420a986ac53b","lessThan":"9cd072788c76595529eb38f42bf94d23852f8534","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98764","source_modified_at":"2026-10-21T12:56:38.602Z","fetched_at":"2026-10-23T18:45:31.882637Z","product":"Linux","vendor":"Linux","versions":[{"version":"3.18","status":"affected"},{"version":"0","lessThan":"3.18","status":"unaffected","versionType":"semver"},{"version":"6.6.160","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.113","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.56","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.10","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98764","source_modified_at":"2026-10-21T12:56:38.602Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"06ac8609d6d185ac18c1d6a6a8a9b99e398bd124","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98764","source_modified_at":"2026-10-21T12:56:38.602Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"9d8761b3c133f6c6a6d3486839dac60e2cf4bfe3","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98764","source_modified_at":"2026-10-21T12:56:38.602Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"7811d8e26c77f8eea79e22d0d14c67ec0658b348","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98764","source_modified_at":"2026-10-21T12:56:38.602Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"35ab269602e1f7c4c0fe6ea3477264bea77eced3","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-98764","source_modified_at":"2026-10-21T12:56:38.602Z","fetched_at":"2026-10-23T18:45:31.882637Z","package":{"name":"Linux","ecosystem":null},"version":"9cd072788c76595529eb38f42bf94d23852f8534","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":0.00168,"percentile":0.05739,"score_date":"2026-10-23"},"published_at":"2026-10-18T15:47:56.225Z","modified_at":"2026-10-21T12:56:38.602Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-98764","fetched_at":"2026-10-23T18:45:31.882637Z","source_modified_at":"2026-10-21T12:56:38.602Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-98764","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/06ac8609d6d185ac18c1d6a6a8a9b99e398bd124"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/9d8761b3c133f6c6a6d3486839dac60e2cf4bfe3"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/7811d8e26c77f8eea79e22d0d14c67ec0658b348"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/35ab269602e1f7c4c0fe6ea3477264bea77eced3"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/9cd072788c76595529eb38f42bf94d23852f8534"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-21T12:56:38.602Z","content_hash":"d00819098e61dfb8c5110a9443bacd15e6f790824030550265a9ddca44bbf6b2"}}