{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-40093", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.163Z", "datePublished": "2025-10-30T09:48:00.807Z", "dateUpdated": "2026-08-05T12:07:44.429Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:07:44.429Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: f_ecm: Refactor bind path to use __free()\n\nAfter an bind/unbind cycle, the ecm->notify_req is left stale. If a\nsubsequent bind fails, the unified error label attempts to free this\nstale request, leading to a NULL pointer dereference when accessing\nep->ops->free_request.\n\nRefactor the error handling in the bind path to use the __free()\nautomatic cleanup mechanism." } ], "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 entire bind/unbind/re-bind sequence that creates and then dereferences the stale `ecm->notify_req` is driven by local writes to `/sys/kernel/config/usb_gadget//UDC` and the function/config symlinks; no USB host traffic, cable event, or physical port access is required, so the bug is reachable purely through local filesystem/syscall access.\nAC:L - The attacker deterministically controls every step — the successful first bind, the unbind that leaves `ecm->notify_req`/`ecm->notify` dangling, and the forced failure of the next bind by exhausting `usb_interface_id()` (MAX_CONFIG_INTERFACES) or `usb_ep_autoconfig()` via extra functions linked into the config between cycles — plus the heap spray that reclaims the freed `usb_request`. No race or condition outside attacker control is involved.\nPR:L - `gadget_dev_desc_UDC_store()` and `ecm_bind()` perform no capability check at all; access is gated only by configfs file permissions, and on Android and embedded/industrial deployments the USB gadget configfs tree is routinely delegated to non-root system/daemon accounts that switch tethering (ECM/NCM/RNDIS) functions.\nUI:N - The attacker performs all configfs writes itself; no victim action, cable plug event, or interaction with another user is needed to reach the stale free.\nS:U - The dangling-pointer free and subsequent heap corruption stay within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `kfree(ecm->notify_req->buf)` reads a pointer out of the reclaimed `struct dummy_request`/`dwc3_request` slab and `usb_ep_free_request()` reads `ep->ops` out of a potentially freed `struct usb_ep`, so an attacker who grooms those generic kmalloc caches gains object-overlap and arbitrary-free primitives readily converted into kernel memory disclosure.\nI:H - `kfree()` of an attacker-controlled pointer read from the freed request, a double free of the `usb_request` itself, and an indirect call through a reclaimable `ep->ops` table together yield classic heap-corruption primitives leading to arbitrary write and privilege escalation.\nA:H - The directly observed effect is a kernel oops — NULL/garbage `ep->ops` dereference in `usb_ep_free_request()` — and the double free independently causes slab corruption and panic, which an unprivileged holder of the configfs tree can trigger repeatedly." } ] } ], "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_ecm.c" ], "versions": [ { "version": "da741b8c56d612b5dd26ffa31341911a5fea23ee", "lessThan": "d3745aaef19198d0c81637a7dd50ef53c4f879b7", "status": "affected", "versionType": "git" }, { "version": "da741b8c56d612b5dd26ffa31341911a5fea23ee", "lessThan": "070f341d86cf2c098d63e484a86c7c1d2696a868", "status": "affected", "versionType": "git" }, { "version": "da741b8c56d612b5dd26ffa31341911a5fea23ee", "lessThan": "15b9faf53ba8719700596e7ef78879ce200e8c2e", "status": "affected", "versionType": "git" }, { "version": "da741b8c56d612b5dd26ffa31341911a5fea23ee", "lessThan": "4630c68bade82f087eaaab22e9a361da2f18d139", "status": "affected", "versionType": "git" }, { "version": "da741b8c56d612b5dd26ffa31341911a5fea23ee", "lessThan": "42988380ac67c76bb9dff8f77d7ef3eefd50b7b5", "status": "affected", "versionType": "git" } ] }, { "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_ecm.c" ], "versions": [ { "version": "2.6.27", "status": "affected" }, { "version": "0", "lessThan": "2.6.27", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.158", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.114", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.55", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17.5", "lessThanOrEqual": "6.17.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18", "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": "2.6.27", "versionEndExcluding": "6.1.158" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.6.114" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.12.55" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.17.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.27", "versionEndExcluding": "6.18" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d3745aaef19198d0c81637a7dd50ef53c4f879b7" }, { "url": "https://git.kernel.org/stable/c/070f341d86cf2c098d63e484a86c7c1d2696a868" }, { "url": "https://git.kernel.org/stable/c/15b9faf53ba8719700596e7ef78879ce200e8c2e" }, { "url": "https://git.kernel.org/stable/c/4630c68bade82f087eaaab22e9a361da2f18d139" }, { "url": "https://git.kernel.org/stable/c/42988380ac67c76bb9dff8f77d7ef3eefd50b7b5" } ], "title": "usb: gadget: f_ecm: Refactor bind path to use __free()", "x_generator": { "engine": "bippy-1.2.0" } } } }