{"id":"CVE-2026-90140","summary":"cuse: wait for pending RCU callbacks on module exit","details":"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-\u003erelease 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-\u003econn)         |\n     call_rcu(delayed_release) ------+---\u003e callback queued\n                                     |\n rmmod cuse                          |\n  cuse_exit()                        |\n   cuse_channel_destroy()            |\n   ...                               |\n   return                            |\n                                     |\n \u003cmodule text freed\u003e                 |\n                                     |  rcu_do_batch()\n                                     |   delayed_release()\n                                     |    fc-\u003erelease()\n                                     |     -\u003e 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.","modified":"2026-09-19T03:47:28.778829517Z","published":"2026-09-17T16:06:37.824Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90140.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/389bd349ddbcf90dbd8a4f2a4ab6e552d53df134"},{"type":"WEB","url":"https://git.kernel.org/stable/c/45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4deb3edead0c0e172cc7349e8855d741d3c5e162"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7fe415e1cd8fa875be263670c0ab47109818abb6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ac5c499413385cea3e0220d6050408d50842891d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c40f3f24839f8404325a2099e26c2a04786ae309"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90140.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90140"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"bfbab62ca69f72bcd14ea30de1fb98f6080ad464"},{"fixed":"7fe415e1cd8fa875be263670c0ab47109818abb6"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a8f650b93e55764ca9ff8e1ddebc151f57024086"},{"fixed":"45ae914b2f6ea56fc2f1c017fdee4e995bcb4c0e"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"535e9bd0e8f8d8cfdc29de7cdb902b5041427fe6"},{"fixed":"ac5c499413385cea3e0220d6050408d50842891d"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"053fc4f755ad43cf35210677bcba798ccdc48d0c"},{"fixed":"a1b46aee33d83f14ed62d7fdef1a91d3e0b732a9"},{"fixed":"389bd349ddbcf90dbd8a4f2a4ab6e552d53df134"},{"fixed":"c40f3f24839f8404325a2099e26c2a04786ae309"},{"fixed":"4deb3edead0c0e172cc7349e8855d741d3c5e162"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.15.166"},{"fixed":"5.15.221"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.1.107"},{"fixed":"6.1.188"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.6.48"},{"fixed":"6.6.157"}]}],"versions":["v5.15.220","v5.15.219","v5.15.218","v5.15.217","v5.15.216","v5.15.215","v5.15.214","v5.15.213","v5.15.212","v5.15.211","v5.15.210","v5.15.209","v5.15.208","v5.15.207","v5.15.206","v5.15.205","v5.15.204","v5.15.203","v5.15.202","v5.15.201","v5.15.200","v5.15.199","v5.15.198","v5.15.197","v5.15.196","v5.15.195","v5.15.194","v5.15.193","v5.15.192","v5.15.191","v5.15.190","v5.15.189","v5.15.188","v5.15.187","v5.15.186","v5.15.185","v5.15.184","v5.15.183","v5.15.182","v5.15.181","v5.15.180","v5.15.179","v5.15.178","v5.15.177","v5.15.176","v5.15.175","v5.15.174","v5.15.173","v5.15.172","v5.15.171","v5.15.170","v5.15.169","v5.15.168","v5.15.167","v5.15.166","v6.1.187","v6.1.186","v6.1.185","v6.1.184","v6.1.183","v6.1.182","v6.1.181","v6.1.180","v6.1.179","v6.1.178","v6.1.177","v6.1.176","v6.1.175","v6.1.174","v6.1.173","v6.1.172","v6.1.171","v6.1.170","v6.1.169","v6.1.168","v6.1.167","v6.1.166","v6.1.165","v6.1.164","v6.1.163","v6.1.162","v6.1.161","v6.1.160","v6.1.159","v6.1.158","v6.1.157","v6.1.156","v6.1.155","v6.1.154","v6.1.153","v6.1.152","v6.1.151","v6.1.150","v6.1.149","v6.1.148","v6.1.147","v6.1.146","v6.1.145","v6.1.144","v6.1.143","v6.1.142","v6.1.141","v6.1.140","v6.1.139","v6.1.138","v6.1.137","v6.1.136","v6.1.135","v6.1.134","v6.1.133","v6.1.132","v6.1.131","v6.1.130","v6.1.129","v6.1.128","v6.1.127","v6.1.126","v6.1.125","v6.1.124","v6.1.123","v6.1.122","v6.1.121","v6.1.120","v6.1.119","v6.1.118","v6.1.117","v6.1.116","v6.1.115","v6.1.114","v6.1.113","v6.1.112","v6.1.111","v6.1.110","v6.1.109","v6.1.108","v6.1.107","v6.6.156","v6.6.155","v6.6.154","v6.6.153","v6.6.152","v6.6.151","v6.6.150","v6.6.149","v6.6.148","v6.6.147","v6.6.146","v6.6.145","v6.6.144","v6.6.143","v6.6.142","v6.6.141","v6.6.140","v6.6.139","v6.6.138","v6.6.137","v6.6.136","v6.6.135","v6.6.134","v6.6.133","v6.6.132","v6.6.131","v6.6.130","v6.6.129","v6.6.128","v6.6.127","v6.6.126","v6.6.125","v6.6.124","v6.6.123","v6.6.122","v6.6.121","v6.6.120","v6.6.119","v6.6.118","v6.6.117","v6.6.116","v6.6.115","v6.6.114","v6.6.113","v6.6.112","v6.6.111","v6.6.110","v6.6.109","v6.6.108","v6.6.107","v6.6.106","v6.6.105","v6.6.104","v6.6.103","v6.6.102","v6.6.101","v6.6.100","v6.6.99","v6.6.98","v6.6.97","v6.6.96","v6.6.95","v6.6.94","v6.6.93","v6.6.92","v6.6.91","v6.6.90","v6.6.89","v6.6.88","v6.6.87","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