{"api_version":"1","generated_at":"2026-04-25T23:29:13+00:00","cve":"CVE-2026-31667","urls":{"html":"https://cve.report/CVE-2026-31667","api":"https://cve.report/api/cve/CVE-2026-31667.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31667","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31667"},"summary":{"title":"Input: uinput - fix circular locking dependency with ff-core","description":"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)","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-24 15:16:46","updated_at":"2026-04-24 17:51:40"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/1534661043c434b81cfde26b97a2fb2460329cf0","name":"https://git.kernel.org/stable/c/1534661043c434b81cfde26b97a2fb2460329cf0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a3d6c9c053c9c605651508569230ead633b13f76","name":"https://git.kernel.org/stable/c/a3d6c9c053c9c605651508569230ead633b13f76","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/1e09dfbb4f5d20ee111f92325a00f85778a5f328","name":"https://git.kernel.org/stable/c/1e09dfbb4f5d20ee111f92325a00f85778a5f328","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/974f7b138c3a96dd5cd53d1b33409cd7b2229dc6","name":"https://git.kernel.org/stable/c/974f7b138c3a96dd5cd53d1b33409cd7b2229dc6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4cda78d6f8bf2b700529f2fbccb994c3e826d7c2","name":"https://git.kernel.org/stable/c/4cda78d6f8bf2b700529f2fbccb994c3e826d7c2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/271ee71a1917b89f6d73ec82dd091c33d92ee617","name":"https://git.kernel.org/stable/c/271ee71a1917b89f6d73ec82dd091c33d92ee617","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/71a9729f412e2c692a35c542e14b706fb342927f","name":"https://git.kernel.org/stable/c/71a9729f412e2c692a35c542e14b706fb342927f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/546c18a14924eb521fe168d916d7ce28f1e13c1d","name":"https://git.kernel.org/stable/c/546c18a14924eb521fe168d916d7ce28f1e13c1d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31667","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31667","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ff462551235d8d7d843a005950bc90924fcedede 71a9729f412e2c692a35c542e14b706fb342927f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ff462551235d8d7d843a005950bc90924fcedede 271ee71a1917b89f6d73ec82dd091c33d92ee617 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ff462551235d8d7d843a005950bc90924fcedede 974f7b138c3a96dd5cd53d1b33409cd7b2229dc6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ff462551235d8d7d843a005950bc90924fcedede 546c18a14924eb521fe168d916d7ce28f1e13c1d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ff462551235d8d7d843a005950bc90924fcedede a3d6c9c053c9c605651508569230ead633b13f76 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ff462551235d8d7d843a005950bc90924fcedede 1e09dfbb4f5d20ee111f92325a00f85778a5f328 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ff462551235d8d7d843a005950bc90924fcedede 1534661043c434b81cfde26b97a2fb2460329cf0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected ff462551235d8d7d843a005950bc90924fcedede 4cda78d6f8bf2b700529f2fbccb994c3e826d7c2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.19","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.19 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.253 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.203 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.169 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.135 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.82 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.23 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.13 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/input/misc/uinput.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"71a9729f412e2c692a35c542e14b706fb342927f","status":"affected","version":"ff462551235d8d7d843a005950bc90924fcedede","versionType":"git"},{"lessThan":"271ee71a1917b89f6d73ec82dd091c33d92ee617","status":"affected","version":"ff462551235d8d7d843a005950bc90924fcedede","versionType":"git"},{"lessThan":"974f7b138c3a96dd5cd53d1b33409cd7b2229dc6","status":"affected","version":"ff462551235d8d7d843a005950bc90924fcedede","versionType":"git"},{"lessThan":"546c18a14924eb521fe168d916d7ce28f1e13c1d","status":"affected","version":"ff462551235d8d7d843a005950bc90924fcedede","versionType":"git"},{"lessThan":"a3d6c9c053c9c605651508569230ead633b13f76","status":"affected","version":"ff462551235d8d7d843a005950bc90924fcedede","versionType":"git"},{"lessThan":"1e09dfbb4f5d20ee111f92325a00f85778a5f328","status":"affected","version":"ff462551235d8d7d843a005950bc90924fcedede","versionType":"git"},{"lessThan":"1534661043c434b81cfde26b97a2fb2460329cf0","status":"affected","version":"ff462551235d8d7d843a005950bc90924fcedede","versionType":"git"},{"lessThan":"4cda78d6f8bf2b700529f2fbccb994c3e826d7c2","status":"affected","version":"ff462551235d8d7d843a005950bc90924fcedede","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/input/misc/uinput.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.19"},{"lessThan":"2.6.19","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.253","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.203","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.169","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.135","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.82","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.23","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.13","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.253","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.203","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.169","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.135","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.82","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.23","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.13","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"2.6.19","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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)"}],"providerMetadata":{"dateUpdated":"2026-04-24T14:45:15.937Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"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"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31667","datePublished":"2026-04-24T14:45:15.937Z","dateReserved":"2026-03-09T15:48:24.129Z","dateUpdated":"2026-04-24T14:45:15.937Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-24 15:16:46","lastModifiedDate":"2026-04-24 17:51:40","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31667","Ordinal":"1","Title":"Input: uinput - fix circular locking dependency with ff-core","CVE":"CVE-2026-31667","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31667","Ordinal":"1","NoteData":"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)","Type":"Description","Title":"Input: uinput - fix circular locking dependency with ff-core"}]}}}