{ "affected": [ { "ranges": [ { "events": [ { "introduced": "3cfcfc102a5e57b021b786a755a38935e357797d" }, { "fixed": "3ff45361e9469e85c0f86b8e7b82c63e50bab8ef" }, { "fixed": "f85a83774d7f4e2ac71c0c384df0dfb6f7d0179a" }, { "fixed": "5e9a94539b1ec17a89177d952badfd0d844d694a" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "0" }, { "last_affected": "b97c37978ca825557d331c9012e0c1ddc0e42364" }, { "last_affected": "bfa9d86d39a0fe4685f90c3529aa9bd62a9d97a8" }, { "last_affected": "bb336cd8d5ecb69c430ebe3e7bcff68471d93fa8" }, { "last_affected": "dd292e884c649f9b1c18af0ec75ca90b390cd044" }, { "last_affected": "934212a623cbab851848b6de377eb476718c3e4c" }, { "last_affected": "5e6013ae2c8d420faea553d363935f65badd32c3" }, { "last_affected": "9806c2393cd2ab0a8e7bb9ffae02ce20e3112ec4" }, { "last_affected": "996997d1fb2126feda550d6adcedcbd94911fc69" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "4.19.311" }, { "fixed": "4.20" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "5.4.273" }, { "fixed": "5.5" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "5.10.214" }, { "fixed": "5.11" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "5.15.153" }, { "fixed": "5.16" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "6.1.83" }, { "fixed": "6.2" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "6.6.23" }, { "fixed": "6.7" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "6.7.11" }, { "fixed": "6.8" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" }, { "events": [ { "introduced": "6.8.2" }, { "fixed": "6.9" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" } ] }, { "package": { "ecosystem": "Linux", "name": "Kernel" }, "ranges": [ { "events": [ { "introduced": "6.9.0" }, { "fixed": "6.18.51" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.19.0" }, { "fixed": "7.2.4" } ], "type": "ECOSYSTEM" } ] } ], "database_specific": { "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89544.json" }, "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nSUNRPC: fix gssx_dec_option_array error path bugs\n\nFour coupled defects in the gssx XDR option-array decoder make the\nerror paths unsafe: a NULL deref in the caller, a refcount leak on\nthe decoded group_info, and a latent use-after-free that the leak\nfix would otherwise expose.\n\ngssx_dec_option_array() sets oa-\u003ecount = 1 before allocating\noa-\u003edata. If that allocation fails, -ENOMEM is returned with\noa-\u003ecount == 1 and oa-\u003edata == NULL. All other error paths jump\nto free_oa: which frees oa-\u003edata and NULLs it but also leaves\noa-\u003ecount == 1. The caller trusts the count:\n\n gssp_accept_sec_context_upcall()\n gssx_dec_accept_sec_context()\n gssx_dec_option_array() /* fails, count=1 data=NULL */\n data = res.options.data[0].value /* NULL deref */\n\nIndependently, free_creds: releases the partially decoded svc_cred\nwith a bare kfree(creds). gssx_dec_linux_creds() installs a\ngroups_alloc() result into creds-\u003ecr_group_info; that object is\nkvmalloc-backed and refcounted, and only put_group_info() reaches\nkvfree(). A plain kfree(creds) drops the wrapper and leaks the\ngroup_info allocation.\n\nThe natural fix for the leak is to call free_svc_cred(creds) before\nkfree(creds), but free_svc_cred() invokes put_group_info() on\ncreds-\u003ecr_group_info unconditionally when non-NULL. The existing\nout_free_groups: path in gssx_dec_linux_creds() already called\ngroups_free() on that pointer without clearing it, so once\nfree_svc_cred() is wired in, the subsequent put_group_info() would\ntouch freed memory.\n\nFix all four together:\n\n - Move the oa-\u003ecount = 1 assignment below the oa-\u003edata allocation\n so it is never set when oa-\u003edata is NULL.\n - Reset oa-\u003ecount to 0 at free_oa: so count and data stay\n coherent and the caller sees an empty option array.\n - Call free_svc_cred(creds) before kfree(creds) at free_creds:\n so the refcounted cr_group_info is released. free_svc_cred()\n either NULL-guards each field explicitly (cr_group_info has\n an if() check) or delegates to a helper that is NULL-safe\n itself (kfree for the string fields, gss_mech_put() which\n guards with if(gm) at gss_mech_switch.c:342), so it is safe\n to call on a partially decoded svc_cred where only\n cr_uid/cr_gid/cr_group_info have been written and everything\n else is zero from kzalloc.\n - In gssx_dec_linux_creds()'s out_free_groups: path, release\n cr_group_info with put_group_info() rather than groups_free()\n so the teardown matches free_svc_cred()'s refcount-aware path,\n and clear the pointer so a later free_svc_cred() on the same\n creds does not release it a second time.", "id": "CVE-2026-89544", "modified": "2026-09-15T03:31:07.899383933Z", "published": "2026-09-11T19:44:20.424Z", "references": [ { "type": "WEB", "url": "https://git.kernel.org/stable/c/3ff45361e9469e85c0f86b8e7b82c63e50bab8ef" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/5e9a94539b1ec17a89177d952badfd0d844d694a" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/f85a83774d7f4e2ac71c0c384df0dfb6f7d0179a" }, { "type": "ADVISORY", "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89544.json" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89544" }, { "type": "PACKAGE", "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git" } ], "schema_version": "1.9.0", "severity": [ { "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "type": "CVSS_V3" } ], "summary": "SUNRPC: fix gssx_dec_option_array error path bugs" }