{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31667","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-03-09T15:48:24.129Z","datePublished":"2026-04-24T14:45:15.937Z","dateUpdated":"2026-05-11T22:13:16.401Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-05-11T22:13:16.401Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nInput: uinput - fix circular locking dependency with ff-core\n\nA lockdep circular locking dependency warning can be triggered\nreproducibly when using a force-feedback gamepad with uinput (for\nexample, playing ELDEN RING under Wine with a Flydigi Vader 5\ncontroller):\n\n  ff->mutex -> udev->mutex -> input_mutex -> dev->mutex -> ff->mutex\n\nThe cycle is caused by four lock acquisition paths:\n\n1. ff upload: input_ff_upload() holds ff->mutex and calls\n   uinput_dev_upload_effect() -> uinput_request_submit() ->\n   uinput_request_send(), which acquires udev->mutex.\n\n2. device create: uinput_ioctl_handler() holds udev->mutex and calls\n   uinput_create_device() -> input_register_device(), which acquires\n   input_mutex.\n\n3. device register: input_register_device() holds input_mutex and\n   calls kbd_connect() -> input_register_handle(), which acquires\n   dev->mutex.\n\n4. evdev release: evdev_release() calls input_flush_device() under\n   dev->mutex, which calls input_ff_flush() acquiring ff->mutex.\n\nFix this by introducing a new state_lock spinlock to protect\nudev->state and udev->dev access in uinput_request_send() instead of\nacquiring udev->mutex.  The function only needs to atomically check\ndevice state and queue an input event into the ring buffer via\nuinput_dev_event() -- both operations are safe under a spinlock\n(ktime_get_ts64() and wake_up_interruptible() do not sleep).  This\nbreaks the ff->mutex -> udev->mutex link since a spinlock is a leaf in\nthe lock ordering and cannot form cycles with mutexes.\n\nTo keep state transitions visible to uinput_request_send(), protect\nwrites to udev->state in uinput_create_device() and\nuinput_destroy_device() with the same state_lock spinlock.\n\nAdditionally, move init_completion(&request->done) from\nuinput_request_send() to uinput_request_submit() before\nuinput_request_reserve_slot().  Once the slot is allocated,\nuinput_flush_requests() may call complete() on it at any time from\nthe destroy path, so the completion must be initialised before the\nrequest becomes visible.\n\nLock ordering after the fix:\n\n  ff->mutex -> state_lock (spinlock, leaf)\n  udev->mutex -> state_lock (spinlock, leaf)\n  udev->mutex -> input_mutex -> dev->mutex -> ff->mutex (no back-edge)"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"}}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/input/misc/uinput.c"],"versions":[{"version":"ff462551235d8d7d843a005950bc90924fcedede","lessThan":"71a9729f412e2c692a35c542e14b706fb342927f","status":"affected","versionType":"git"},{"version":"ff462551235d8d7d843a005950bc90924fcedede","lessThan":"271ee71a1917b89f6d73ec82dd091c33d92ee617","status":"affected","versionType":"git"},{"version":"ff462551235d8d7d843a005950bc90924fcedede","lessThan":"974f7b138c3a96dd5cd53d1b33409cd7b2229dc6","status":"affected","versionType":"git"},{"version":"ff462551235d8d7d843a005950bc90924fcedede","lessThan":"546c18a14924eb521fe168d916d7ce28f1e13c1d","status":"affected","versionType":"git"},{"version":"ff462551235d8d7d843a005950bc90924fcedede","lessThan":"a3d6c9c053c9c605651508569230ead633b13f76","status":"affected","versionType":"git"},{"version":"ff462551235d8d7d843a005950bc90924fcedede","lessThan":"1e09dfbb4f5d20ee111f92325a00f85778a5f328","status":"affected","versionType":"git"},{"version":"ff462551235d8d7d843a005950bc90924fcedede","lessThan":"1534661043c434b81cfde26b97a2fb2460329cf0","status":"affected","versionType":"git"},{"version":"ff462551235d8d7d843a005950bc90924fcedede","lessThan":"4cda78d6f8bf2b700529f2fbccb994c3e826d7c2","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/input/misc/uinput.c"],"versions":[{"version":"2.6.19","status":"affected"},{"version":"0","lessThan":"2.6.19","status":"unaffected","versionType":"semver"},{"version":"5.10.253","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.203","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.169","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.135","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.82","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.23","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"6.19.13","lessThanOrEqual":"6.19.*","status":"unaffected","versionType":"semver"},{"version":"7.0","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"5.10.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.1.169"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.6.135"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.12.82"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.18.23"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"6.19.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.19","versionEndExcluding":"7.0"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/71a9729f412e2c692a35c542e14b706fb342927f"},{"url":"https://git.kernel.org/stable/c/271ee71a1917b89f6d73ec82dd091c33d92ee617"},{"url":"https://git.kernel.org/stable/c/974f7b138c3a96dd5cd53d1b33409cd7b2229dc6"},{"url":"https://git.kernel.org/stable/c/546c18a14924eb521fe168d916d7ce28f1e13c1d"},{"url":"https://git.kernel.org/stable/c/a3d6c9c053c9c605651508569230ead633b13f76"},{"url":"https://git.kernel.org/stable/c/1e09dfbb4f5d20ee111f92325a00f85778a5f328"},{"url":"https://git.kernel.org/stable/c/1534661043c434b81cfde26b97a2fb2460329cf0"},{"url":"https://git.kernel.org/stable/c/4cda78d6f8bf2b700529f2fbccb994c3e826d7c2"}],"title":"Input: uinput - fix circular locking dependency with ff-core","x_generator":{"engine":"bippy-1.2.0"}}}}