CVE-2026-98858

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-98858", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.376Z", "datePublished": "2026-10-18T15:51:19.578Z", "dateUpdated": "2026-10-19T09:26:52.852Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:26:52.852Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix task_work add use-after-free with SQPOLL\n\nFor SQPOLL, the sqpoll thread runs task_work off its own list and\ndoesn't need to be told about it, so it can pop and complete a request\nas soon as mpscq_push() has published it. If that was the last request\nholding the ring alive, io_ring_exit_work() then frees the ctx, stops\nthe thread, and with it the tctx, while io_req_normal_work_add() is\nstill looking at both after the push:\n\n BUG: KASAN: slab-use-after-free in io_req_normal_work_add+0x439/0x510\n Read of size 4 at addr ff11000000ca0000 by task repro/55\n (...)\n BUG: KASAN: slab-use-after-free in queue_work_on+0x25/0x70\n Write of size 8 at addr ff11000000c3bd00 by task repro/55\n\nHold an RCU read lock across the add, like io_req_local_work_add() already\ndoes, and have io_ring_exit_work() wait for a grace period for SQPOLL rings\nas well before freeing the ctx."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["io_uring/io_uring.c", "io_uring/tw.c"], "versions": [{"version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b", "lessThan": "42b3332efacfd2140be4cd0dedad4fb96b8ae90e", "status": "affected", "versionType": "git"}, {"version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b", "lessThan": "891bd8335a0de3bb15c3b797ce3026bbb0dbef6c", "status": "affected", "versionType": "git"}, {"version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b", "lessThan": "395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3", "status": "affected", "versionType": "git"}, {"version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b", "lessThan": "a92193c91e8839fe5fc209616ea95465ae4b919d", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["io_uring/io_uring.c", "io_uring/tw.c"], "versions": [{"version": "6.9", "status": "affected"}, {"version": "0", "lessThan": "6.9", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.113", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.56", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.10", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "6.9", "versionEndExcluding": "6.12.113"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "6.18.56"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.2.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.9", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/42b3332efacfd2140be4cd0dedad4fb96b8ae90e"}, {"url": "https://git.kernel.org/stable/c/891bd8335a0de3bb15c3b797ce3026bbb0dbef6c"}, {"url": "https://git.kernel.org/stable/c/395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3"}, {"url": "https://git.kernel.org/stable/c/a92193c91e8839fe5fc209616ea95465ae4b919d"}], "title": "io_uring: fix task_work add use-after-free with SQPOLL", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["io_uring/io_uring.c", "io_uring/tw.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "42b3332efacfd2140be4cd0dedad4fb96b8ae90e", "status": "affected", "version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b", "versionType": "git"}, {"lessThan": "891bd8335a0de3bb15c3b797ce3026bbb0dbef6c", "status": "affected", "version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b", "versionType": "git"}, {"lessThan": "395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3", "status": "affected", "version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b", "versionType": "git"}, {"lessThan": "a92193c91e8839fe5fc209616ea95465ae4b919d", "status": "affected", "version": "af5d68f8892f8ee8f137648b79ceb2abc153a19b", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["io_uring/io_uring.c", "io_uring/tw.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.9"}, {"lessThan": "6.9", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.113", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.56", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.10", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix task_work add use-after-free with SQPOLL\n\nFor SQPOLL, the sqpoll thread runs task_work off its own list and\ndoesn't need to be told about it, so it can pop and complete a request\nas soon as mpscq_push() has published it. If that was the last request\nholding the ring alive, io_ring_exit_work() then frees the ctx, stops\nthe thread, and with it the tctx, while io_req_normal_work_add() is\nstill looking at both after the push:\n\n BUG: KASAN: slab-use-after-free in io_req_normal_work_add+0x439/0x510\n Read of size 4 at addr ff11000000ca0000 by task repro/55\n (...)\n BUG: KASAN: slab-use-after-free in queue_work_on+0x25/0x70\n Write of size 8 at addr ff11000000c3bd00 by task repro/55\n\nHold an RCU read lock across the add, like io_req_local_work_add() already\ndoes, and have io_ring_exit_work() wait for a grace period for SQPOLL rings\nas well before freeing the ctx."}], "id": "CVE-2026-98858", "lastModified": "2026-10-19T10:19:49.880", "metrics": {}, "published": "2026-10-18T16:17:40.257", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/42b3332efacfd2140be4cd0dedad4fb96b8ae90e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/891bd8335a0de3bb15c3b797ce3026bbb0dbef6c"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a92193c91e8839fe5fc209616ea95465ae4b919d"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: io_uring: fix task_work add use-after-free with SQPOLL", "id": "2555237", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2555237"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nio_uring: fix task_work add use-after-free with SQPOLL\nFor SQPOLL, the sqpoll thread runs task_work off its own list and\ndoesn't need to be told about it, so it can pop and complete a request\nas soon as mpscq_push() has published it. If that was the last request\nholding the ring alive, io_ring_exit_work() then frees the ctx, stops\nthe thread, and with it the tctx, while io_req_normal_work_add() is\nstill looking at both after the push:\nBUG: KASAN: slab-use-after-free in io_req_normal_work_add+0x439/0x510\nRead of size 4 at addr ff11000000ca0000 by task repro/55\n(...)\nBUG: KASAN: slab-use-after-free in queue_work_on+0x25/0x70\nWrite of size 8 at addr ff11000000c3bd00 by task repro/55\nHold an RCU read lock across the add, like io_req_local_work_add() already\ndoes, and have io_ring_exit_work() wait for a grace period for SQPOLL rings\nas well before freeing the ctx.", "A flaw was found in the Linux kernel's io_uring subsystem. When submission queue polling (SQPOLL) is enabled, a race condition can cause the polling thread to free the ring context while another operation is still accessing it. A local user can exploit this use-after-free flaw to crash the system, resulting in a Denial of Service (DoS), or potentially achieve privilege escalation."], "name": "CVE-2026-98858", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-10-18T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-98858\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-98858\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98858.mbox"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[af5d68f8892f8ee8f137648b79ceb2abc153a19b,42b3332efacfd2140be4cd0dedad4fb96b8ae90e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[af5d68f8892f8ee8f137648b79ceb2abc153a19b,891bd8335a0de3bb15c3b797ce3026bbb0dbef6c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[af5d68f8892f8ee8f137648b79ceb2abc153a19b,395b25968fe854d4efaa19a8e9b7a5b6d1b3eea3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[af5d68f8892f8ee8f137648b79ceb2abc153a19b,a92193c91e8839fe5fc209616ea95465ae4b919d)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.9"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,6.9)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.113,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.56,7.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.10,8.0.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-10-18T22:00:20.102855+00:00", "updated": "2026-10-24T14:00:17.825333+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-416", "CWE-825"]}