{"id":"CVE-2026-97903","revision":null,"records":[{"revision":"2f157eadcd6e49a185574d2f52098a81","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-97903","aliases":[],"title":"exit: hold a reference to thread_pid across proc_flush_pid","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nexit: hold a reference to thread_pid across proc_flush_pid\n\nCommit 0a36bad01731 (\"release_task: kill the no longer needed\nget/put_pid(thread_pid)\") removed the reference around proc_flush_pid().\nIt assumed that free_pids(post.pids) at the end of release_task() would\nkeep thread_pid alive until then.\n\nThat assumption is wrong.  __change_pid() only records a detached PID in\npost.pids when pid_has_task() is false for every PIDTYPE.  If another task\nstill uses the exiting task's PID as its process group or session ID,\n__unhash_process() removes the exiting task's PIDTYPE_PID link but leaves\nthe PID out of post.pids.  release_task() therefore holds no reference to\nit after dropping tasklist_lock.\n\nThe other task can then remove the remaining PIDTYPE links.  Its\nfree_pids() call schedules delayed_put_pid(), and the RCU callback can free\nthe PID before the first release_task() reaches proc_flush_pid().\n\nAn unprivileged reproducer races wait4(-1) against setsid() to trigger this\nordering.  Three of three fresh v7.2 KASAN boots reported:\n\n    BUG: KASAN: slab-use-after-free in\n    proc_invalidate_siblings_dcache+0x3e2/0x3f0\n    Read of size 8 by task h7_pid_reaper/1921\n\n    Call Trace:\n     proc_invalidate_siblings_dcache\n     release_task\n     wait_consider_task\n     __do_wait\n     do_wait\n     kernel_wait4\n\n    Freed by task 0:\n     kmem_cache_free\n     put_pid\n     delayed_put_pid\n     rcu_core\n\n    Last potentially related work creation:\n     __call_rcu_common\n     free_pids\n     ksys_setsid\n\nKASAN identified a 144-byte object from the pid cache and located the bad\nread 80 bytes into the freed object, matching pid->inodes.  With an\nexplicit reference, three of three fresh boots completed without a KASAN\nreport.  The concurrent RCU callback dropped its reference while\nproc_flush_pid() was protected, and the balancing put_pid() performed the\nfinal free afterward.\n\nTake a reference before __unhash_process() clears p->thread_pid and release\nit after proc_flush_pid() completes.\n\nA tested source reproducer is available privately on request.  No\ncontrolled read or write, information leak, or privilege escalation is\nclaimed.  The mainline patch applies directly to v6.19.y and newer;\nv6.16.y through v6.18.y need a context-adjusted backport.","state":0,"publishedAt":"2026-09-25T10:22:29.852+00:00","modifiedAt":"2026-10-19T09:10:29.542+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/exit.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"0a36bad01731e71568bdd365764d38b6bd576ab0\",\n                            \"lessThan\": \"bcb0936862f2b653114d9bd582ca26990ef54a64\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0a36bad01731e71568bdd365764d38b6bd576ab0\",\n                            \"lessThan\": \"96803a12e8ac15f0a1b4b151db59038f12304e58\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"0a36bad01731e71568bdd365764d38b6bd576ab0\",\n                            \"lessThan\": \"cdd812d0683dee14ead02c9eded568685e61b23f\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\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/exit.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.16\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.16\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.53\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.7\",\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":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/bcb0936862f2b653114d9bd582ca26990ef54a64","https://git.kernel.org/stable/c/96803a12e8ac15f0a1b4b151db59038f12304e58","https://git.kernel.org/stable/c/cdd812d0683dee14ead02c9eded568685e61b23f"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-97903","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-97903","identifiers":["CVE-2026-97903"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. Missing entries do not establish absence of exploitation.","generation":"2026-11-09T01:02:10.7447709+00:00","complete":true,"records":1769,"lastAttemptAt":"2026-11-09T01:02:10.7447709+00:00","lastSuccessAt":"2026-11-09T01:02:10.8951096+00:00","error":null,"lastVerifiedAt":"2026-11-09T01:02:10.8951131+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-eaa64dac63caa79c8d4905619258c41c51b39e461b996124e1a21b5e85e7e738-06f887e3cff12cdbfc1e6b879a816e143efd9863ce6bea9ec9f7392bb9208c22","complete":true,"records":421267,"lastAttemptAt":"2026-11-09T01:02:10.4183693+00:00","lastSuccessAt":"2026-11-09T00:02:15.5944139+00:00","error":"InvalidOperationException","lastVerifiedAt":"2026-11-09T00:02:15.6996628+00:00","snapshotPublishedAt":"2026-11-08T23:22:42+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-ad1daa57fd0d4d4ba18256a2340415a0","complete":false,"records":13654,"lastAttemptAt":"2026-11-09T01:13:59.0733242+00:00","lastSuccessAt":"2026-11-09T01:13:59.069+00:00","error":null,"lastVerifiedAt":"2026-11-09T01:13:59.069+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13626,"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":"2026-11-09T01:02:10.7447709+00:00","complete":true,"records":1096,"lastAttemptAt":"2026-11-09T01:02:10.7447709+00:00","lastSuccessAt":"2026-11-09T01:02:10.8958676+00:00","error":null,"lastVerifiedAt":"2026-11-09T01:02:10.8958678+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-cfd5ade15e524f2aab9bbdd1588fc1b0","complete":true,"records":13666,"lastAttemptAt":"2026-11-09T01:02:13.0307833+00:00","lastSuccessAt":"2026-11-09T01:02:13.027+00:00","error":null,"lastVerifiedAt":"2026-11-09T01:02:13.027+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":"2026-11-09T01:02:10.6696355+00:00","lastSuccessAt":"2026-11-08T11:07:07.068788+00:00","error":null,"lastVerifiedAt":"2026-11-09T01:02:10.6696355+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":"2026-11-09T01:02:10.4684348+00:00","lastSuccessAt":"2026-11-06T19:03:17.0399903+00:00","error":null,"lastVerifiedAt":"2026-11-09T01:02:10.4684348+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-3b1150af6d7ada2c07356cbab4ead5224c1485027890f71c71d0742cddf0b9e8","complete":true,"records":3055,"lastAttemptAt":"2026-11-09T01:02:10.6816953+00:00","lastSuccessAt":"2026-11-09T00:02:23.4330288+00:00","error":null,"lastVerifiedAt":"2026-11-09T01:02:10.6816953+00:00","snapshotPublishedAt":"2026-11-08T23:17:54+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":"2026-11-09T01:02:10.5692363+00:00","lastSuccessAt":"2026-11-08T11:06:56.2918717+00:00","error":null,"lastVerifiedAt":"2026-11-09T01:02:10.5692363+00:00","snapshotPublishedAt":"2026-11-08T11:02:50+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}