CVE-2026-31721: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_hid: move list and spinlock inits from bind to alloc There was an issue when you did the following: - setup and bind an hid gadget - open /dev/hidg0 - use the resulting fd in EPOLL_CTL_ADD - unbind the UDC - bind the UDC - use the fd in EPOLL_CTL_DEL When CONFIG_DEBUG_LIST was enabled, a list_del corruption was reported within remove_wait_queue (via ep_remove_wait_queue). After some debugging I found out that the queues, which f_hid registers via poll_wait were the problem. These were initialized using init_waitqueue_head inside hidg_bind. So effectively, the bind function re-initialized the queues while there were still items in them. The solution is to move the initialization from hidg_bind to hidg_alloc to extend their lifetimes to the lifetime of the function instance. Additionally, I found many other possibly problematic init calls in the bind function, which I moved as well.

Affected products

• Linux Linux Kernel: from 3.19, before 5.10.253 (fixed in 5.10.253); from 5.11, before 5.15.203 (fixed in 5.15.203); from 5.16, before 6.1.169 (fixed in 6.1.169); from 6.2, before 6.6.135 (fixed in 6.6.135); from 6.7, before 6.12.81 (fixed in 6.12.81); from 6.13, before 6.18.22 (fixed in 6.18.22); …

Published 2026-05-01. Last modified 2026-06-17.