{"id":"CVE-2026-89990","published":"2026-09-16T11:17:10.133","lastModified":"2026-09-16T15:18:22.800","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: lock mutex in ceph_mds_check_access()\n\nMDS session OPEN handling replaces mdsc->s_cap_auths under\nmdsc->mutex, freeing the previous array and its strings.\n\nceph_mds_check_access() traverses this array without holding the\nmutex.  A concurrent session reopen can therefore free the array while\nit is being inspected, resulting in a use-after-free like this:\n\n  Unable to handle kernel paging request at virtual address 003aaad64b2c8bb9\n  [...]\n  Internal error: Oops: 0000000096000004 [#1]  SMP\n  Modules linked in:\n  CPU: 56 UID: 2953037534 PID: 1253231 Comm: php-cgi8.4 Not tainted 6.18.45-i2-ampere #1146 NONE\n  [..]\n  pc : ceph_mds_check_access+0xd4/0x550\n  lr : ceph_mds_check_access+0xc8/0x550\n  [...]\n  Call trace:\n   ceph_mds_check_access+0xd4/0x550 (P)\n   ceph_atomic_open+0x138/0xbe8\n   path_openat+0xa24/0xfa8\n   do_filp_open+0x94/0x158\n   do_sys_openat2+0x88/0xf8","cvssScore":9.8,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/729c1ff670ece6f3d4b1738365a0b2f90d487523","tags":[]},{"url":"https://git.kernel.org/stable/c/a61c6ae1dae2611082b831b4aaa780878099c012","tags":[]},{"url":"https://git.kernel.org/stable/c/ca5bfea2045ef2eb3305cf2a9d8da549b76c37d3","tags":[]},{"url":"https://git.kernel.org/stable/c/df1a97d5313fccadb08390306d49b194fb027392","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"The flaw allows a use-after-free condition in the Ceph MDS session handling, which can lead to kernel crashes or arbitrary code execution if exploited.","exploitability":"Exploitation requires concurrent access to the MDS session and the ability to trigger a session reopen, making it moderately complex.","blast_radius":"If exploited, the vulnerability could result in a denial of service or potentially arbitrary code execution on the affected system.","remediation":"Upgrade to the specific version 6.18.45-i2-ampere #1146 or later.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["kernel","use-after-free","denial-of-service","arbitrary-code-execution"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-09-28T08:58:39.602Z"}}