Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-31667— Input: uinput - fix circular locking dependency with ff-core

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于uinput中ff-core循环锁定依赖，可能导致死锁。

CVSS 7.8 · High EPSS 0.14% · P3

Possible ATT&CK Techniques 1 AI

T1562

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux ff462551235d8d7d843a005950bc90924fcedede< 71a9729f412e2c692a35c542e14b706fb342927f affected
ff462551235d8d7d843a005950bc90924fcedede< 271ee71a1917b89f6d73ec82dd091c33d92ee617 affected
ff462551235d8d7d843a005950bc90924fcedede< 974f7b138c3a96dd5cd53d1b33409cd7b2229dc6 affected
ff462551235d8d7d843a005950bc90924fcedede< 546c18a14924eb521fe168d916d7ce28f1e13c1d affected
ff462551235d8d7d843a005950bc90924fcedede< a3d6c9c053c9c605651508569230ead633b13f76 affected
ff462551235d8d7d843a005950bc90924fcedede< 1e09dfbb4f5d20ee111f92325a00f85778a5f328 affected
ff462551235d8d7d843a005950bc90924fcedede< 1534661043c434b81cfde26b97a2fb2460329cf0 affected
ff462551235d8d7d843a005950bc90924fcedede< 4cda78d6f8bf2b700529f2fbccb994c3e826d7c2 affected
… +10 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-31667

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Input: uinput - fix circular locking dependency with ff-core
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: Input: uinput - fix circular locking dependency with ff-core A lockdep circular locking dependency warning can be triggered reproducibly when using a force-feedback gamepad with uinput (for example, playing ELDEN RING under Wine with a Flydigi Vader 5 controller): ff->mutex -> udev->mutex -> input_mutex -> dev->mutex -> ff->mutex The cycle is caused by four lock acquisition paths: 1. ff upload: input_ff_upload() holds ff->mutex and calls uinput_dev_upload_effect() -> uinput_request_submit() -> uinput_request_send(), which acquires udev->mutex. 2. device create: uinput_ioctl_handler() holds udev->mutex and calls uinput_create_device() -> input_register_device(), which acquires input_mutex. 3. device register: input_register_device() holds input_mutex and calls kbd_connect() -> input_register_handle(), which acquires dev->mutex. 4. evdev release: evdev_release() calls input_flush_device() under dev->mutex, which calls input_ff_flush() acquiring ff->mutex. Fix this by introducing a new state_lock spinlock to protect udev->state and udev->dev access in uinput_request_send() instead of acquiring udev->mutex. The function only needs to atomically check device state and queue an input event into the ring buffer via uinput_dev_event() -- both operations are safe under a spinlock (ktime_get_ts64() and wake_up_interruptible() do not sleep). This breaks the ff->mutex -> udev->mutex link since a spinlock is a leaf in the lock ordering and cannot form cycles with mutexes. To keep state transitions visible to uinput_request_send(), protect writes to udev->state in uinput_create_device() and uinput_destroy_device() with the same state_lock spinlock. Additionally, move init_completion(&request->done) from uinput_request_send() to uinput_request_submit() before uinput_request_reserve_slot(). Once the slot is allocated, uinput_flush_requests() may call complete() on it at any time from the destroy path, so the completion must be initialised before the request becomes visible. Lock ordering after the fix: ff->mutex -> state_lock (spinlock, leaf) udev->mutex -> state_lock (spinlock, leaf) udev->mutex -> input_mutex -> dev->mutex -> ff->mutex (no back-edge)
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于uinput中ff-core循环锁定依赖，可能导致死锁。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux ff462551235d8d7d843a005950bc90924fcedede ~ 71a9729f412e2c692a35c542e14b706fb342927f -
Linux Linux 2.6.19 -

II. Public POCs for CVE-2026-31667

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-31667

请登录查看更多情报信息。

Same Patch Batch · Linux · 2026-04-24 · 138 CVEs total

CVE-2026-31637 9.8 CRITICAL rxrpc: reject undecryptable rxkad response tickets
CVE-2026-31536 9.8 CRITICAL smb: server: let send_done handle a completion without IB_SEND_SIGNALED
CVE-2026-31589 9.8 CRITICAL mm: call ->free_folio() directly in folio_unmap_invalidate()
CVE-2026-31669 9.8 CRITICAL mptcp: fix slab-use-after-free in __inet_lookup_established
CVE-2026-31668 9.8 CRITICAL seg6: separate dst_cache for input and output paths in seg6 lwtunnel
CVE-2026-31649 9.8 CRITICAL net: stmmac: fix integer underflow in chain mode
CVE-2026-31633 9.8 CRITICAL rxrpc: Fix integer overflow in rxgk_verify_response()
CVE-2026-31607 9.8 CRITICAL usbip: validate number_of_packets in usbip_pack_ret_submit()
CVE-2026-31608 9.8 CRITICAL smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list
CVE-2026-31609 9.8 CRITICAL smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()
CVE-2026-31657 9.8 CRITICAL batman-adv: hold claim backbone gateways by reference
CVE-2026-31659 9.8 CRITICAL batman-adv: reject oversized global TT response buffers
CVE-2026-31636 9.1 CRITICAL rxrpc: fix RESPONSE authenticator parser OOB read
CVE-2026-31588 8.8 HIGH KVM: x86: Use scratch field in MMIO fragment to hold small write values
CVE-2026-31570 8.8 HIGH can: gw: fix OOB heap access in cgw_csum_crc8_rel()
CVE-2026-31622 8.8 HIGH NFC: digital: Bounds check NFC-A cascade depth in SDD response handler
CVE-2026-31558 8.8 HIGH LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
CVE-2026-31553 8.8 HIGH KVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()
CVE-2026-31629 8.8 HIGH nfc: llcp: add missing return after LLCP_CLOSED checks
CVE-2026-31611 8.6 HIGH ksmbd: require 3 sub-authorities before reading sub_auth[2]

Showing top 20 of 138 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-31667

No comments yet

Leave a comment