CVE-2026-31721
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Record status
- Analyzed
Affected
- Linux Kernel < 5.10.253
- Linux Kernel < 5.15.203
- Linux Kernel < 6.1.169
- Linux Kernel < 6.6.135
- Linux Kernel < 6.12.81
- Linux Kernel < 6.18.22
- Linux Kernel < 6.19.12
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-31721.md and follow it. Check whether this project is affected by CVE-2026-31721. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/13440c0db227c5db01da751ed966dde4cdd2ea18
- https://git.kernel.org/stable/c/26a879a41ed960b3fb4ec773ef2788c515c0e488
- https://git.kernel.org/stable/c/4e0a88254ad59f6c53a34bf5fa241884ec09e8b2
- https://git.kernel.org/stable/c/5d1bb391ceeebb28327703dd07af8c6324af298f
- https://git.kernel.org/stable/c/81aee4500055876883658b024b6fb61801afe134
- https://git.kernel.org/stable/c/8ec6a58586f195a88479edcdb0b8027c39f12d03
- https://git.kernel.org/stable/c/de93e0862169b5539e00c2b9980b93fd80c37c0d
- https://git.kernel.org/stable/c/f7d00ee1c8082c8a134340aaf16d71a27e29c362
References
- https://git.kernel.org/stable/c/13440c0db227c5db01da751ed966dde4cdd2ea18
- https://git.kernel.org/stable/c/26a879a41ed960b3fb4ec773ef2788c515c0e488
- https://git.kernel.org/stable/c/4e0a88254ad59f6c53a34bf5fa241884ec09e8b2
- https://git.kernel.org/stable/c/5d1bb391ceeebb28327703dd07af8c6324af298f
- https://git.kernel.org/stable/c/81aee4500055876883658b024b6fb61801afe134
- https://git.kernel.org/stable/c/8ec6a58586f195a88479edcdb0b8027c39f12d03
- https://git.kernel.org/stable/c/de93e0862169b5539e00c2b9980b93fd80c37c0d
- https://git.kernel.org/stable/c/f7d00ee1c8082c8a134340aaf16d71a27e29c362