{"cve":"CVE-2026-80824","nvd":{"published":"2026-09-04T16:18:10.233","modified":"2026-10-19T09:17:17.293","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: usbfs: fix use-after-free of usb_device in usbdev_release()\n\nusbdev_release() drops its reference to the struct usb_device before\ndraining the list of completed async URBs, but that drain path reads back\nthrough the same object: free_async() calls dec_usb_memory_use_count()\nfor any URB whose buffer came from the usbfs mmap() region, and its first\nstatement is bus_to_hcd(ps->dev->bus).\n\nAfter a disconnect the usbfs reference can be the last one, in which case\nusb_put_dev() frees the device and the subsequent loop reads offset 80 of\nfreed memory and uses the result as a struct usb_hcd *, which\nhcd_buffer_free_pages() then dereferences.\n\nThis is reachable by an unprivileged process that has read/write access to\na /dev/bus/usb node: mmap() the fd, submit one URB with a buffer inside the\nmapping, wait for the device to be unplugged, then munmap() and close().\nIt reproduces on every attempt rather than being a race, because a live\nMAP_SHARED vma holds a reference on the struct file, so usbdev_release()\ncannot run until the last vma is gone and the freeing branch of\ndec_usb_memory_use_count() is always taken.\n\n  BUG: KASAN: slab-use-after-free in dec_usb_memory_use_count+0x3ae/0x410\n  Read of size 8 at addr ffff8880122ee050 by task poc/769\n  CPU: 1 UID: 1000 PID: 769 Comm: poc Tainted: G    B    6.12.94 #3\n\n  Call Trace:\n   dec_usb_memory_use_count+0x3ae/0x410\n   free_async+0x2aa/0x4f0\n   usbdev_release+0x375/0x460\n   __fput+0x3ea/0xb50\n   __x64_sys_close+0x86/0x100\n\n  Allocated by task 11:\n   usb_alloc_dev+0x55/0xd90\n   hub_event+0x2524/0x43d0\n\n  Freed by task 769:\n   kfree+0x121/0x360\n   device_release+0xd2/0x280\n   usb_put_dev+0x23/0x30\n   usbdev_release+0x2d8/0x460\n\nRelease the device reference after the drain loop instead. Nothing between\nthe two points requires it to have been dropped.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/0a960b88c5979f853019d4dc4957dfbeeb193440","https://git.kernel.org/stable/c/0dd68b5d01d022fc9c5e71c82a82b0a94d3d0671","https://git.kernel.org/stable/c/47a7f98fbb5006d46d15a3a210ffdc61448a4f19","https://git.kernel.org/stable/c/5f08c45bdcfd28d1171de38c5ef29fc89a76eedc","https://git.kernel.org/stable/c/65879e0a452ca2a234b9475e0c11aff7a4343738"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:52:03.409947763+00:00"},"epss":{"cve":"CVE-2026-80824","score":0.00195,"percentile":0.09117,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}