{"cve":"CVE-2026-90140","nvd":{"published":"2026-09-17T17:17:06.710","modified":"2026-10-19T09:19:03.810","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncuse: wait for pending RCU callbacks on module exit\n\nSince commit 053fc4f755ad (\"fuse: fix UAF in rcu pathwalks\"),\nfuse_conn_put() frees the fuse_conn through call_rcu() rather than\nsynchronously.  For cuse, fc->release is cuse_fc_release(), which\nlives in the cuse module.  If the module is removed before the RCU\ngrace period ends, the callback jumps into freed module memory:\n\n      userspace / module unload      |        RCU softirq\n~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n close(/dev/cuse)                    |\n  cuse_channel_release()             |\n   fuse_dev_release()                |\n    fuse_conn_put(fch->conn)         |\n     call_rcu(delayed_release) ------+---> callback queued\n                                     |\n rmmod cuse                          |\n  cuse_exit()                        |\n   cuse_channel_destroy()            |\n   ...                               |\n   return                            |\n                                     |\n <module text freed>                 |\n                                     |  rcu_do_batch()\n                                     |   delayed_release()\n                                     |    fc->release()\n                                     |     -> cuse_fc_release()\n                                     |        ^^^ freed text!\n\nThe freed module text is unmapped by vfree(), so the jump into the\nstale callback triggers a page-fault Oops.  If the virtual address\nis subsequently reused, the callback could execute unrelated code\n(undefined behaviour).\n\nFix this by calling rcu_barrier() in cuse_exit() so that any pending\nfuse_conn release callback completes before the module is removed.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/389bd349ddbcf90dbd8a4f2a4ab6e552d53df134","https://git.kernel.org/stable/c/45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e","https://git.kernel.org/stable/c/4deb3edead0c0e172cc7349e8855d741d3c5e162","https://git.kernel.org/stable/c/7fe415e1cd8fa875be263670c0ab47109818abb6","https://git.kernel.org/stable/c/a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:55:23.253742848+00:00"},"epss":{"cve":"CVE-2026-90140","score":0.00211,"percentile":0.11293,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}