{"id":"CVE-2023-53665","summary":"md: don't dereference mddev after export_rdev()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmd: don't dereference mddev after export_rdev()\n\nExcept for initial reference, mddev-\u003ekobject is referenced by\nrdev-\u003ekobject, and if the last rdev is freed, there is no guarantee that\nmddev is still valid. Hence mddev should not be used anymore after\nexport_rdev().\n\nThis problem can be triggered by following test for mdadm at very\nlow rate:\n\nNew file: mdadm/tests/23rdev-lifetime\n\ndevname=${dev0##*/}\ndevt=`cat /sys/block/$devname/dev`\npid=\"\"\nruntime=2\n\nclean_up_test() {\n        pill -9 $pid\n        echo clear \u003e /sys/block/md0/md/array_state\n}\n\ntrap 'clean_up_test' EXIT\n\nadd_by_sysfs() {\n        while true; do\n                echo $devt \u003e /sys/block/md0/md/new_dev\n        done\n}\n\nremove_by_sysfs(){\n        while true; do\n                echo remove \u003e /sys/block/md0/md/dev-${devname}/state\n        done\n}\n\necho md0 \u003e /sys/module/md_mod/parameters/new_array || die \"create md0 failed\"\n\nadd_by_sysfs &\npid=\"$pid $!\"\n\nremove_by_sysfs &\npid=\"$pid $!\"\n\nsleep $runtime\nexit 0\n\nTest cmd:\n\n./test --save-logs --logdir=/tmp/ --keep-going --dev=loop --tests=23rdev-lifetime\n\nTest result:\n\ngeneral protection fault, probably for non-canonical address 0x6b6b6b6b6b6b6bcb: 0000 [#4] PREEMPT SMP\nCPU: 0 PID: 1292 Comm: test Tainted: G      D W          6.5.0-rc2-00121-g01e55c376936 #562\nRIP: 0010:md_wakeup_thread+0x9e/0x320 [md_mod]\nCall Trace:\n \u003cTASK\u003e\n mddev_unlock+0x1b6/0x310 [md_mod]\n rdev_attr_store+0xec/0x190 [md_mod]\n sysfs_kf_write+0x52/0x70\n kernfs_fop_write_iter+0x19a/0x2a0\n vfs_write+0x3b5/0x770\n ksys_write+0x74/0x150\n __x64_sys_write+0x22/0x30\n do_syscall_64+0x40/0x90\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nFix this problem by don't dereference mddev after export_rdev().","modified":"2026-03-20T12:33:17.229135Z","published":"2025-10-07T15:21:23.808Z","related":["SUSE-SU-2025:21040-1","SUSE-SU-2025:21052-1","SUSE-SU-2025:21056-1","SUSE-SU-2025:21064-1","SUSE-SU-2025:4057-1","SUSE-SU-2025:4128-1","SUSE-SU-2025:4132-1","SUSE-SU-2025:4140-1","SUSE-SU-2025:4141-1","SUSE-SU-2025:4301-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53665.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/7deac114be5fb25a4e865212ed0feaf5f85f2a28"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ad430ad0669d2757377373390d68e1454fc7a344"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53665.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53665"},{"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":"3ce94ce5d05ae89190a23f6187f64d8f4b2d3782"},{"fixed":"ad430ad0669d2757377373390d68e1454fc7a344"},{"fixed":"7deac114be5fb25a4e865212ed0feaf5f85f2a28"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-53665.json"}}],"schema_version":"1.7.5"}