CVE-2026-72071

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-72071", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-09T03:40:39.904Z", "datePublished": "2026-08-15T05:52:23.215Z", "dateUpdated": "2026-08-17T05:40:01.974Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:40:01.974Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing/user_events: Fix use-after-free in user_event_mm_dup()\n\nuser_event_mm_dup() walks the parent mm's enabler list locklessly under\nrcu_read_lock() during fork() (from copy_process()); it does not take\nevent_mutex:\n\n\trcu_read_lock();\n\tlist_for_each_entry_rcu(enabler, &old_mm->enablers, mm_enablers_link)\n\t\tenabler->event = user_event_get(orig->event);\n\nuser_event_enabler_destroy() removes an enabler from that list with\nlist_del_rcu() and then, without waiting for a grace period, drops the\nenabler's user_event reference with user_event_put() and frees the enabler\nwith kfree(). A reader that loaded the enabler before the list_del_rcu()\ncan still be walking it, which leads to two use-after-frees:\n\n - kfree(enabler) frees the enabler while that reader dereferences\n enabler->event.\n\n - user_event_put() may drop the last reference to the user_event, which\n is then freed (via delayed_destroy_user_event() on a work queue), while\n the same reader does user_event_get(orig->event) on it.\n\nBoth are reachable by an unprivileged task that can open user_events_data:\none multithreaded process that registers an enabler and then concurrently\nunregisters it and calls fork() triggers the race. KASAN reports a\nslab-use-after-free in user_event_mm_dup() during clone(), with a\n\"refcount_t: addition on 0\" warning when the user_event is freed.\n\nThe enabler use-after-free was found first; the user_event one was reported\nby XIAO WU, and the earlier enabler-only fix did not address it.\n\nDefer both the user_event_put() and the kfree(enabler) to a work item\nqueued with queue_rcu_work(), so they run only after an RCU grace period,\nonce all readers walking the enabler list have finished. The put must run\nin process context because user_event_put() takes event_mutex on the last\nreference, so a work queue is used rather than call_rcu(). The now-unlocked\nput lets the locked argument of user_event_enabler_destroy() be removed;\nall callers are updated."}], "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 bug is reached only through local syscalls (clone/fork via copy_process and ioctl on tracefs user_events_data); there is no network, adjacent-wireless, or physical-device path into user_event_mm_dup or user_event_enabler_destroy.\nAC:L - A single multithreaded attacker process can register an enabler, then concurrently issue DIAG_IOCSUNREG and fork/clone; the attacker controls both sides of the RCU race, and the fix commit reports reliable KASAN slab-use-after-free reproduction.\nPR:L - Non-persist DIAG_IOCSREG and DIAG_IOCSUNREG enforce no CAP_SYS_ADMIN or perfmon check; only write access to tracefs user_events_data is required, and tracing deployments (Android/Perfetto, ChromeOS, developer tracefs gid mounts) intentionally grant that to unprivileged local users.\nUI:N - The attacker performs registration, concurrent unregistration, and fork entirely within their own process; no victim action, mount, or cooperating user is required beyond running the exploit code.\nS:U - The coupled slab use-after-frees occur in kernel heap during local fork handling and do not cross a VM, IOMMU, or sandbox boundary; impact is standard in-kernel memory corruption on the same host.\nC:H - Fork-time RCU traversal dereferences freed enabler and user_event objects and calls user_event_get on a freed user_event (refcount addition on zero per KASAN), enabling attacker-influenced kernel memory reads via slab grooming.\nI:H - Premature kfree of enabler and user_event while fork duplicates enablement lets an attacker reclaim kmalloc slabs holding tracepoint and trace_event_call state, supporting heap spray and arbitrary kernel write or control-flow hijack primitives.\nA:H - KASAN reports slab-use-after-free in user_event_mm_dup during clone, and repeated concurrent unreg/fork reliably oopses or panics the kernel even before full exploitation, constituting dependable local denial of service."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/trace/trace_events_user.c"], "versions": [{"version": "7235759084a4f8524a46bd2638885ff3b34ce279", "lessThan": "25acb6711da6fa0382744fa92bd6d42a22c1ae68", "status": "affected", "versionType": "git"}, {"version": "7235759084a4f8524a46bd2638885ff3b34ce279", "lessThan": "95400e7039cdfeb0b53652d521d766f1698cae95", "status": "affected", "versionType": "git"}, {"version": "7235759084a4f8524a46bd2638885ff3b34ce279", "lessThan": "b33ac2d39953efb12f598c0dae242c5f644ea669", "status": "affected", "versionType": "git"}, {"version": "7235759084a4f8524a46bd2638885ff3b34ce279", "lessThan": "05b24f68f78ff3a1ef7f015f7327b35886b741f6", "status": "affected", "versionType": "git"}, {"version": "7235759084a4f8524a46bd2638885ff3b34ce279", "lessThan": "50fd6dd755c6e48a38af2fa4621167eea56829c2", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/trace/trace_events_user.c"], "versions": [{"version": "6.4", "status": "affected"}, {"version": "0", "lessThan": "6.4", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.40", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.5", "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": "6.4", "versionEndExcluding": "6.6.148"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.12.97"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.18.40"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.1.5"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/25acb6711da6fa0382744fa92bd6d42a22c1ae68"}, {"url": "https://git.kernel.org/stable/c/95400e7039cdfeb0b53652d521d766f1698cae95"}, {"url": "https://git.kernel.org/stable/c/b33ac2d39953efb12f598c0dae242c5f644ea669"}, {"url": "https://git.kernel.org/stable/c/05b24f68f78ff3a1ef7f015f7327b35886b741f6"}, {"url": "https://git.kernel.org/stable/c/50fd6dd755c6e48a38af2fa4621167eea56829c2"}], "title": "tracing/user_events: Fix use-after-free in user_event_mm_dup()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/trace/trace_events_user.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "25acb6711da6fa0382744fa92bd6d42a22c1ae68", "status": "affected", "version": "7235759084a4f8524a46bd2638885ff3b34ce279", "versionType": "git"}, {"lessThan": "95400e7039cdfeb0b53652d521d766f1698cae95", "status": "affected", "version": "7235759084a4f8524a46bd2638885ff3b34ce279", "versionType": "git"}, {"lessThan": "b33ac2d39953efb12f598c0dae242c5f644ea669", "status": "affected", "version": "7235759084a4f8524a46bd2638885ff3b34ce279", "versionType": "git"}, {"lessThan": "05b24f68f78ff3a1ef7f015f7327b35886b741f6", "status": "affected", "version": "7235759084a4f8524a46bd2638885ff3b34ce279", "versionType": "git"}, {"lessThan": "50fd6dd755c6e48a38af2fa4621167eea56829c2", "status": "affected", "version": "7235759084a4f8524a46bd2638885ff3b34ce279", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/trace/trace_events_user.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.4"}, {"lessThan": "6.4", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.148", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.97", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.40", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.5", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "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\ntracing/user_events: Fix use-after-free in user_event_mm_dup()\n\nuser_event_mm_dup() walks the parent mm's enabler list locklessly under\nrcu_read_lock() during fork() (from copy_process()); it does not take\nevent_mutex:\n\n\trcu_read_lock();\n\tlist_for_each_entry_rcu(enabler, &old_mm->enablers, mm_enablers_link)\n\t\tenabler->event = user_event_get(orig->event);\n\nuser_event_enabler_destroy() removes an enabler from that list with\nlist_del_rcu() and then, without waiting for a grace period, drops the\nenabler's user_event reference with user_event_put() and frees the enabler\nwith kfree(). A reader that loaded the enabler before the list_del_rcu()\ncan still be walking it, which leads to two use-after-frees:\n\n - kfree(enabler) frees the enabler while that reader dereferences\n enabler->event.\n\n - user_event_put() may drop the last reference to the user_event, which\n is then freed (via delayed_destroy_user_event() on a work queue), while\n the same reader does user_event_get(orig->event) on it.\n\nBoth are reachable by an unprivileged task that can open user_events_data:\none multithreaded process that registers an enabler and then concurrently\nunregisters it and calls fork() triggers the race. KASAN reports a\nslab-use-after-free in user_event_mm_dup() during clone(), with a\n\"refcount_t: addition on 0\" warning when the user_event is freed.\n\nThe enabler use-after-free was found first; the user_event one was reported\nby XIAO WU, and the earlier enabler-only fix did not address it.\n\nDefer both the user_event_put() and the kfree(enabler) to a work item\nqueued with queue_rcu_work(), so they run only after an RCU grace period,\nonce all readers walking the enabler list have finished. The put must run\nin process context because user_event_put() takes event_mutex on the last\nreference, so a work queue is used rather than call_rcu(). The now-unlocked\nput lets the locked argument of user_event_enabler_destroy() be removed;\nall callers are updated."}], "id": "CVE-2026-72071", "lastModified": "2026-08-17T06:18:05.650", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-08-15T06:21:16.820", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/05b24f68f78ff3a1ef7f015f7327b35886b741f6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/25acb6711da6fa0382744fa92bd6d42a22c1ae68"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/50fd6dd755c6e48a38af2fa4621167eea56829c2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/95400e7039cdfeb0b53652d521d766f1698cae95"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b33ac2d39953efb12f598c0dae242c5f644ea669"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: tracing/user_events: Fix use-after-free in user_event_mm_dup()", "id": "2516653", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2516653"}, "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": ["A flaw was found in the Linux kernel's `tracing/user_events` component. An unprivileged local attacker can exploit a race condition during process forking within the `user_event_mm_dup()` function. This use-after-free vulnerability occurs when an enabler is prematurely freed while still being accessed. Successful exploitation can lead to system instability or a denial of service (DoS) due to memory corruption."], "name": "CVE-2026-72071", "public_date": "2026-08-15T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-72071\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-72071\nhttps://lore.kernel.org/linux-cve-announce/2026081519-CVE-2026-72071-db78@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7235759084a4f8524a46bd2638885ff3b34ce279,25acb6711da6fa0382744fa92bd6d42a22c1ae68)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7235759084a4f8524a46bd2638885ff3b34ce279,95400e7039cdfeb0b53652d521d766f1698cae95)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7235759084a4f8524a46bd2638885ff3b34ce279,b33ac2d39953efb12f598c0dae242c5f644ea669)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7235759084a4f8524a46bd2638885ff3b34ce279,05b24f68f78ff3a1ef7f015f7327b35886b741f6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[7235759084a4f8524a46bd2638885ff3b34ce279,50fd6dd755c6e48a38af2fa4621167eea56829c2)"}}], "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": "semver", "value": "6.4"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.4)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.148,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.97,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.40,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.5,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc3,*]"}}], "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": "2026-08-15T08:30:06.148608+00:00", "updated": "2026-08-18T02:00:05.410010+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-416", "CWE-362", "CWE-825"]}