{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-52933", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-06-09T07:44:35.369Z", "datePublished": "2026-06-24T07:14:24.678Z", "dateUpdated": "2026-08-05T12:31:51.192Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:31:51.192Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/poll: fix signed comparison in io_poll_get_ownership()\n\nio_poll_get_ownership() uses a signed comparison to check whether\npoll_refs has reached the threshold for the slowpath:\n\n if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS))\n\natomic_read() returns int (signed). When IO_POLL_CANCEL_FLAG\n(BIT(31)) is set in poll_refs, the value becomes negative in\nsigned arithmetic, so the >= 128 comparison always evaluates to\nfalse and the slowpath is never taken.\n\nFix this by casting the atomic_read() result to unsigned int\nbefore the comparison, so that the cancel flag is treated as a\nlarge positive value and correctly triggers the slowpath." } ], "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" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable path is reached by local `io_uring_setup()`/`io_uring_enter()` submissions of poll and cancel operations, not by remote packets or physical access.\nAC:L - An attacker can create the ring, choose pollable file descriptors, submit cancels/removes, and generate concurrent wakeups; the race participants are attacker-controlled.\nPR:L - With the default `io_uring_disabled=0`, an unprivileged local user can create and use io_uring; no real root or init-namespace capability is required.\nUI:N - Exploitation does not require another user to mount, open, or process anything; the attacker drives the syscall and file-descriptor activity directly.\nS:U - This is a kernel request-lifetime/ownership bug within the same host kernel security authority, not a VM, IOMMU, or separate security-scope escape.\nC:H - The signedness bug defeats the poll_refs overflow/ownership slow path after cancellation, allowing ref-bit wrap and duplicate ownership/completion of an `io_kiocb`; that is UAF-style kernel memory corruption with plausible memory disclosure.\nI:H - The same duplicate ownership/completion and request lifetime corruption can plausibly be shaped into arbitrary kernel memory modification or control-flow compromise, so integrity impact is high.\nA:H - At minimum, corrupted poll ownership and duplicate completion can trigger kernel warnings, NULL dereferences, UAF crashes, or hangs in a local attacker-controlled loop." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/poll.c" ], "versions": [ { "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea", "lessThan": "81bf96b0abbfa4cd47ea32e12596aed3855fb2f3", "status": "affected", "versionType": "git" }, { "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea", "lessThan": "cf522703d4f194991615763697ae25a3f9539763", "status": "affected", "versionType": "git" }, { "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea", "lessThan": "fc47043f3d9af3efa407665b47f8378ec691ba18", "status": "affected", "versionType": "git" }, { "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea", "lessThan": "ea0697129807d718037f618221037aa0660ee3c5", "status": "affected", "versionType": "git" }, { "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea", "lessThan": "c6d191164dc81838d8dbf452a6000f68c558d1ae", "status": "affected", "versionType": "git" }, { "version": "a26a35e9019fd70bf3cf647dcfdae87abc7bacea", "lessThan": "326941b22806cbf2df1fbfe902b7908b368cce42", "status": "affected", "versionType": "git" }, { "version": "4b702b7d11ce1b9d26fc6d7c5a7ef4ac1d455048", "status": "affected", "versionType": "git" }, { "version": "bc4e6ee16778149811333a969a7a893d4cc110c5", "status": "affected", "versionType": "git" }, { "version": "5.15.82", "lessThan": "5.16", "status": "affected", "versionType": "semver" }, { "version": "6.0.11", "lessThan": "6.1", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "io_uring/poll.c" ], "versions": [ { "version": "6.1", "status": "affected" }, { "version": "0", "lessThan": "6.1", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.140", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.86", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.27", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0.4", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1", "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": "6.1", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.6.140" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.12.86" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.18.27" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "7.0.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "7.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.82" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/81bf96b0abbfa4cd47ea32e12596aed3855fb2f3" }, { "url": "https://git.kernel.org/stable/c/cf522703d4f194991615763697ae25a3f9539763" }, { "url": "https://git.kernel.org/stable/c/fc47043f3d9af3efa407665b47f8378ec691ba18" }, { "url": "https://git.kernel.org/stable/c/ea0697129807d718037f618221037aa0660ee3c5" }, { "url": "https://git.kernel.org/stable/c/c6d191164dc81838d8dbf452a6000f68c558d1ae" }, { "url": "https://git.kernel.org/stable/c/326941b22806cbf2df1fbfe902b7908b368cce42" } ], "title": "io_uring/poll: fix signed comparison in io_poll_get_ownership()", "x_generator": { "engine": "bippy-1.2.0" } } } }