Tracker / CVE-2026-31721
CVE-2026-31721
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 and versions
| linux | linux_kernel |
|---|---|
| linux | linux_kernel · 3.19 → 5.10.253 |
| linux | linux_kernel · 5.11 → 5.15.203 |
| linux | linux_kernel · 5.16 → 6.1.169 |
| linux | linux_kernel · 6.13 → 6.18.22 |
| linux | linux_kernel · 6.19 → 6.19.12 |
| linux | linux_kernel · 6.2 → 6.6.135 |
| linux | linux_kernel · 6.7 → 6.12.81 |