{"id":"CVE-2024-56670","url":"https://www.cyber-defence.io/tools/cve/CVE-2024-56670","generatedAt":"2026-10-28T10:47:39.909Z","title":"In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_serial: Fix the issue that gs_start_io crashed due to accessing null pointer Considering that in some extreme cases, when u_serial driver is accessed by multiple threads,…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: u_serial: Fix the issue that gs_start_io crashed due to accessing null pointer\n\nConsidering that in some extreme cases,\nwhen u_serial driver is accessed by multiple threads,\nThread A is executing the open operation and calling the gs_open,\nThread B is executing the disconnect operation and calling the\ngserial_disconnect function,The port->port_usb pointer will be set to NULL.\n\nE.g.\n    Thread A                                 Thread B\n    gs_open()                                gadget_unbind_driver()\n    gs_start_io()                            composite_disconnect()\n    gs_start_rx()                            gserial_disconnect()\n    ...                                      ...\n    spin_unlock(&port->port_lock)\n    status = usb_ep_queue()                  spin_lock(&port->port_lock)\n    spin_lock(&port->port_lock)              port->port_usb = NULL\n    gs_free_requests(port->port_usb->in)     spin_unlock(&port->port_lock)\n    Crash\n\nThis causes thread A to access a null pointer (port->port_usb is null)\nwhen calling the gs_free_requests function, causing a crash.\n\nIf port_usb is NULL, the release request will be skipped as it\nwill be done by gserial_disconnect.\n\nSo add a null pointer check to gs_start_io before attempting\nto access the value of the pointer port->port_usb.\n\nCall trace:\n gs_start_io+0x164/0x25c\n gs_open+0x108/0x13c\n tty_open+0x314/0x638\n chrdev_open+0x1b8/0x258\n do_dentry_open+0x2c4/0x700\n vfs_open+0x2c/0x3c\n path_openat+0xa64/0xc60\n do_filp_open+0xb8/0x164\n do_sys_openat2+0x84/0xf0\n __arm64_sys_openat+0x70/0x9c\n invoke_syscall+0x58/0x114\n el0_svc_common+0x80/0xe0\n do_el0_svc+0x1c/0x28\n el0_svc+0x38/0x68","published":"2024-12-27T15:15:27.000Z","lastModified":"2026-06-17T08:12:42.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-476"],"affected":["linux/linux kernel"],"epss":{"score":0.00226,"percentile":0.13284,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.23%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/1247e1df086aa6c17ab53cd1bedce70dd7132765","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/28b3c03a6790de1f6f2683919ad657840f0f0f58","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4cfbca86f6a8b801f3254e0e3c8f2b1d2d64be2b","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4efdfdc32d8d6307f968cd99f1db64468471bab1","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8ca07a3d18f39b1669927ef536e485787e856df6","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c83213b6649d22656b3a4e92544ceeea8a2c6c07","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dd6b0ca6025f64ccb465a6a3460c5b0307ed9c44","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2024-56670","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}