{"id":"CVE-2025-21704","summary":"usb: cdc-acm: Check control transfer buffer size before access","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: cdc-acm: Check control transfer buffer size before access\n\nIf the first fragment is shorter than struct usb_cdc_notification, we can't\ncalculate an expected_size. Log an error and discard the notification\ninstead of reading lengths from memory outside the received data, which can\nlead to memory corruption when the expected_size decreases between\nfragments, causing `expected_size - acm-\u003enb_index` to wrap.\n\nThis issue has been present since the beginning of git history; however,\nit only leads to memory corruption since commit ea2583529cd1\n(\"cdc-acm: reassemble fragmented notifications\").\n\nA mitigating factor is that acm_ctrl_irq() can only execute after userspace\nhas opened /dev/ttyACM*; but if ModemManager is running, ModemManager will\ndo that automatically depending on the USB device's vendor/product IDs and\nits other interfaces.","modified":"2026-04-02T12:45:12.253473Z","published":"2025-02-22T09:43:37.377Z","related":["SUSE-SU-2025:01919-1","SUSE-SU-2025:01983-1","SUSE-SU-2025:1177-1","SUSE-SU-2025:1178-1","SUSE-SU-2025:1180-1","SUSE-SU-2025:20190-1","SUSE-SU-2025:20192-1","SUSE-SU-2025:20260-1","SUSE-SU-2025:20270-1","USN-7521-2"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21704.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/383d516a0ebc8641372b521c8cb717f0f1834831"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6abb510251e75f875797d8983a830e6731fa281c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7828e9363ac4d23b02419bf2a45b9f1d9fb35646"},{"type":"WEB","url":"https://git.kernel.org/stable/c/871619c2b78fdfe05afb4e8ba548678687beb812"},{"type":"WEB","url":"https://git.kernel.org/stable/c/90dd2f1b7342b9a671a5ea4160f408037b92b118"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a4e1ae5c0533964170197e4fb4f33bc8c1db5cd2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e563b01208f4d1f609bcab13333b6c0e24ce6a01"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f64079bef6a8a7823358c3f352ea29a617844636"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html"},{"type":"WEB","url":"https://project-zero.issues.chromium.org/issues/395107243"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21704.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-21704"},{"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":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"},{"fixed":"a4e1ae5c0533964170197e4fb4f33bc8c1db5cd2"},{"fixed":"90dd2f1b7342b9a671a5ea4160f408037b92b118"},{"fixed":"871619c2b78fdfe05afb4e8ba548678687beb812"},{"fixed":"7828e9363ac4d23b02419bf2a45b9f1d9fb35646"},{"fixed":"6abb510251e75f875797d8983a830e6731fa281c"},{"fixed":"f64079bef6a8a7823358c3f352ea29a617844636"},{"fixed":"383d516a0ebc8641372b521c8cb717f0f1834831"},{"fixed":"e563b01208f4d1f609bcab13333b6c0e24ce6a01"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21704.json"}}],"schema_version":"1.7.5"}