{"id":"CVE-2026-98861","revision":null,"records":[{"revision":"7146a33bb5ea461d80d45e4f0f3b9de6","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98861","aliases":[],"title":"fprobe: Use guard(rcu_sched_notrace) and check rcu_is_watching()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfprobe: Use guard(rcu_sched_notrace) and check rcu_is_watching()\n\nunregister_fprobe() and unregister_fprobe_async() (used by BPF\nkprobe-multi) rely on standard RCU grace periods (synchronize_rcu()\nand call_rcu()) to wait until in-flight fprobe handlers complete before\nfreeing the fprobe.\n\nHowever, if an fprobe handler executes while RCU is not watching (such\nas in the idle loop or nohz_full extended quiescent states), standard\nRCU does not track preemption-disabled sections. Consequently,\nsynchronize_rcu() does not wait for those executions, which can lead\nto a use-after-free if the fprobe is freed immediately after\nunregistration. Ensure handlers exit early when !rcu_is_watching().\n\nFurthermore, fprobe_fgraph_entry() and fprobe_ftrace_entry() previously\nused guard(rcu)() and rcu_read_lock(), which invoke lockdep on every\nhit under CONFIG_PROVE_LOCKING. This adds overhead and can cause lockdep\nrecursion if probed functions interact with lockdep.\n\nSince rhltable_lookup() and rhl_for_each_entry_rcu() use\nrcu_dereference_all_check() (which checks rcu_read_lock_any_held()),\nholding preemption disabled via rcu_read_lock_sched_notrace() is fully\nvalid and sufficient so long as rcu_is_watching() is true.\n\nDefine and use guard(rcu_sched_notrace)() across fprobe_ftrace_entry(),\nfprobe_fgraph_entry(), and fprobe_return(). This eliminates fast-path\nrcu_read_lock() and lockdep overhead while guaranteeing safe grace\nperiod synchronization.","state":0,"publishedAt":"2026-10-18T15:51:22.271+00:00","modifiedAt":"2026-10-19T09:26:55.805+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/trace/fprobe.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"56b4cfcf1518245493c60fd39c56978f508f1816\",\n                            \"lessThan\": \"a85d0f00671b4d4527317c10ba018680f7d8d673\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"657b594b2084b39a4bc6d8493aa2140cb00cea49\",\n                            \"lessThan\": \"dd4a0d4993633b45470abf6da4ea0ca563402245\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"657b594b2084b39a4bc6d8493aa2140cb00cea49\",\n                            \"lessThan\": \"e0a6249190402a28f1e2925a81acf573157d55ef\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a4f6a9005ed6cfd360ef2520430927f05f92ffb0\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6.18.34\",\n                            \"lessThan\": \"6.18.56\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.11\",\n                            \"lessThan\": \"7.1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"kernel/trace/fprobe.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"7.1\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"7.1\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.56\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.10\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/a85d0f00671b4d4527317c10ba018680f7d8d673","https://git.kernel.org/stable/c/dd4a0d4993633b45470abf6da4ea0ca563402245","https://git.kernel.org/stable/c/e0a6249190402a28f1e2925a81acf573157d55ef"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98861","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98861","identifiers":["CVE-2026-98861"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-08T23:02:15.9754883+00:00","complete":true,"records":1769,"lastAttemptAt":"2026-11-08T23:02:15.9754883+00:00","lastSuccessAt":"2026-11-08T23:02:16.1185375+00:00","error":null,"lastVerifiedAt":"2026-11-08T23:02:16.1185396+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"cve-program","scope":"Official CVE Program baseline and cumulative hourly delta; all vendors, published and rejected records","generation":"cve-eaa64dac63caa79c8d4905619258c41c51b39e461b996124e1a21b5e85e7e738-0ee53194438b774350db8ba2be9961094a7945659f4bca5c09ae0ef23c2c3f0c","complete":true,"records":421267,"lastAttemptAt":"2026-11-08T23:02:15.4905694+00:00","lastSuccessAt":"2026-11-08T23:02:15.4057062+00:00","error":null,"lastVerifiedAt":"2026-11-08T23:02:15.4905694+00:00","snapshotPublishedAt":"2026-11-08T22:18:37+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"euvd","scope":"Rolling EUVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-64ec014845cf41e0b44c7812575dade1","complete":false,"records":13654,"lastAttemptAt":"2026-11-08T23:11:05.5177476+00:00","lastSuccessAt":"2026-11-08T23:11:05.509+00:00","error":null,"lastVerifiedAt":"2026-11-08T23:11:05.509+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13457,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-08T23:02:15.9754883+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-08T23:02:15.9754883+00:00","lastSuccessAt":"2026-11-08T23:02:16.1192591+00:00","error":null,"lastVerifiedAt":"2026-11-08T23:02:16.1192597+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-bbd1082fa13b4aff99c01e332b64e44f","complete":true,"records":13666,"lastAttemptAt":"2026-11-08T23:02:17.0620293+00:00","lastSuccessAt":"2026-11-08T23:02:17.059+00:00","error":null,"lastVerifiedAt":"2026-11-08T23:02:17.059+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13706,"expectedIdentifiers":13706,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-980593e6977a6d1b4fb1eed5a1ffe88a468736f89f0a06f710924ad59132c023","complete":true,"records":9914,"lastAttemptAt":"2026-11-08T23:02:15.8370588+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-08T23:02:15.8370588+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-fde804134ecdda0ddd5ff5c26ee1fff5a6fa659311f7ef2e51c6ad54964db0e2","complete":true,"records":1971,"lastAttemptAt":"2026-11-08T23:02:15.64043+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-08T23:02:15.64043+00:00","snapshotPublishedAt":"2026-11-06T18:17:57+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-964c14035e6f0f6478b2870fad6a7ef9f6045876d4a12af2c2e514521e54b6af","complete":true,"records":3055,"lastAttemptAt":"2026-11-08T23:02:15.942926+00:00","lastSuccessAt":"2026-11-08T11:07:12.1927025+00:00","error":null,"lastVerifiedAt":"2026-11-08T23:02:15.942926+00:00","snapshotPublishedAt":"2026-11-08T11:02:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-f8647d7ba64b1ba0dfdc7130944766d5b36d5b77d18fff0c79e651a4cff3c2b9","complete":true,"records":231293,"lastAttemptAt":"2026-11-08T23:02:15.7372001+00:00","lastSuccessAt":"2026-11-08T11:06:56.2918717+00:00","error":null,"lastVerifiedAt":"2026-11-08T23:02:15.7372001+00:00","snapshotPublishedAt":"2026-11-08T11:02:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}