{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80553","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-26T14:34:25.766Z","datePublished":"2026-08-26T14:37:21.774Z","dateUpdated":"2026-08-27T12:40:13.853Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-27T12:40:13.853Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Cancel existing workqueues\n\nThe initialization of the io_work and crw_work workqueues begs the\nquestion of whether they should be un-initialized. Add the corresponding\ncleanup tags in _release_dev to ensure work isn't dispatched after\nthe private struct is free'd."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through local VFIO mediated-device syscalls (read/write/ioctl on /dev/vfio/* and device fds) that start channel I/O or receive CRW events; vfio-ccw has no network, Bluetooth, or physical-bus packet entry point.\nAC:L - This is a close/teardown versus workqueue race where the VFIO client controls both sides: it can submit I/O that queues io_work/crw_work via interrupts or path events, then close or release the device while work is still pending, and retry to win reliably.\nPR:L - Exploitation requires access to an opened vfio-ccw mdev (typical QEMU/libvirt VM operator or delegated /dev/vfio holder on an IBM Z passthrough host), not init-namespace root; mdev creation is admin setup, but triggering the UAF needs only the delegated VFIO fd.\nUI:N - No separate victim action is required; once vfio-ccw passthrough is configured, the attacker issues channel I/O and coordinates device close/release (e.g., hot-unplug or fd teardown) without needing another user to mount media or click anything.\nS:C - On IBM Z/LinuxONE, vfio-ccw exists to pass DASD subchannels into KVM guests; guest-driven channel I/O causes host interrupt/workqueue activity and host-side teardown UAF corrupts hypervisor kernel memory outside the VM security boundary.\nC:H - vfio_ccw_sch_io_todo() and vfio_ccw_crw_todo() dereference freed vfio_ccw_private fields (io_mutex, cp, io_region, crw list, eventfd pointers); per kernel UAF guidance this enables attacker-influenced reuse and arbitrary kernel read primitives.\nI:H - The UAF handlers perform mutex operations, cp_free(), memcpy into io_region, and eventfd_signal() on freed memory, giving heap-sprayable arbitrary write and control-flow hijack potential beyond a simple crash.\nA:H - Use-after-free in deferred I/O/CRW work during device close or release can immediately oops or panic the host kernel from invalid mutex/structure access, and successful exploitation can hang or crash the system even when not leveraged for code execution."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/s390/cio/vfio_ccw_ops.c"],"versions":[{"version":"e5f84dbaea59b4f712dac428c337528b70e1c533","lessThan":"87d569cb35a541b31a184faf982540694d4c9a89","status":"affected","versionType":"git"},{"version":"e5f84dbaea59b4f712dac428c337528b70e1c533","lessThan":"7492ca2d0c5d59add01e267be9f5a6eeb8076fd7","status":"affected","versionType":"git"},{"version":"e5f84dbaea59b4f712dac428c337528b70e1c533","lessThan":"b94b28c1f0fae53b2f2d6180ae6442c9a1558f67","status":"affected","versionType":"git"},{"version":"e5f84dbaea59b4f712dac428c337528b70e1c533","lessThan":"e868ea8be0bc88c6982f48ecf3259d98afd884ae","status":"affected","versionType":"git"},{"version":"e5f84dbaea59b4f712dac428c337528b70e1c533","lessThan":"dc47a98abe6714577a25224534dbd356051097a3","status":"affected","versionType":"git"},{"version":"e5f84dbaea59b4f712dac428c337528b70e1c533","lessThan":"b7ae0f7993867d009a4b554fc1d6d451c10580a0","status":"affected","versionType":"git"},{"version":"e5f84dbaea59b4f712dac428c337528b70e1c533","lessThan":"77f5e888d2e607a0b3141fb95091ad6ef1cca9a2","status":"affected","versionType":"git"},{"version":"e5f84dbaea59b4f712dac428c337528b70e1c533","lessThan":"79c60b2c61105368dcc8444eb45847e21734f7c4","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/s390/cio/vfio_ccw_ops.c"],"versions":[{"version":"4.12","status":"affected"},{"version":"0","lessThan":"4.12","status":"unaffected","versionType":"semver"},{"version":"5.10.267","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.218","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.185","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.153","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.105","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.46","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.10","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","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":"4.12","versionEndExcluding":"5.10.267"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"5.15.218"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.1.185"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.6.153"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.12.105"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"6.18.46"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.1.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.12","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/87d569cb35a541b31a184faf982540694d4c9a89"},{"url":"https://git.kernel.org/stable/c/7492ca2d0c5d59add01e267be9f5a6eeb8076fd7"},{"url":"https://git.kernel.org/stable/c/b94b28c1f0fae53b2f2d6180ae6442c9a1558f67"},{"url":"https://git.kernel.org/stable/c/e868ea8be0bc88c6982f48ecf3259d98afd884ae"},{"url":"https://git.kernel.org/stable/c/dc47a98abe6714577a25224534dbd356051097a3"},{"url":"https://git.kernel.org/stable/c/b7ae0f7993867d009a4b554fc1d6d451c10580a0"},{"url":"https://git.kernel.org/stable/c/77f5e888d2e607a0b3141fb95091ad6ef1cca9a2"},{"url":"https://git.kernel.org/stable/c/79c60b2c61105368dcc8444eb45847e21734f7c4"}],"title":"s390/vfio_ccw: Cancel existing workqueues","x_generator":{"engine":"bippy-1.2.0"}}}}