{"id":"CVE-2026-64563","published":"2026-08-04T07:16:31.220","lastModified":"2026-08-09T19:17:02.237","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrhashtable: clear stale iter->p on table restart\n\nrhashtable_walk_start_check() has two restart paths when resuming a walk.\nWhen iter->walker.tbl is valid, it re-validates iter->p against the table\nand sets iter->p = NULL if the object is gone.  When iter->walker.tbl is\nNULL (table was freed during resize), it resets slot and skip but forgets\nto clear iter->p.\n\nrhashtable_walk_next() then dereferences the stale iter->p, reading\nfreed memory.  This is a use-after-free.\n\nAny caller that does multi-fragment rhashtable walks across\nwalk_stop/walk_start boundaries is affected.  Concrete cases include\nnetlink_diag (__netlink_diag_dump in net/netlink/diag.c) and TIPC\n(tipc_nl_sk_walk in net/tipc/socket.c).\n\nCrash stack (netlink_diag):\n  BUG: KASAN: slab-use-after-free in rhashtable_walk_next+0x365/0x3c0\n  Read of size 8 at addr ffff88801a9d2438 (freed kmalloc-2k, offset 1080)\n  Call Trace:\n   rhashtable_walk_next+0x365/0x3c0 (lib/rhashtable.c:1016)\n   __netlink_diag_dump+0x160/0x760 (net/netlink/diag.c:122)\n   netlink_diag_dump+0xc2/0x240\n   netlink_dump+0x5bc/0x1270\n   netlink_recvmsg+0x7a3/0x980\n   sock_recvmsg+0x1bc/0x200\n   __sys_recvfrom+0x1d4/0x2c0","cvssScore":7.8,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/042fda5c088015f18838e5c692659a7be60aeb26","tags":[]},{"url":"https://git.kernel.org/stable/c/3ff7c1dbf722cf3fa538672452ba182318e0fcc3","tags":[]},{"url":"https://git.kernel.org/stable/c/4169d9fb92f313ff8e7e83d733c1ecdcc93eebd3","tags":[]},{"url":"https://git.kernel.org/stable/c/8173f7e2ce67e6ca1d4763f3da14e5b01ce77456","tags":[]},{"url":"https://git.kernel.org/stable/c/c39643ad99fea749be50615550e8f0e6d6e60694","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"The flaw involves a use-after-free vulnerability in rhashtable_walk_next due to stale pointers not being cleared properly during table restarts, allowing for potential memory corruption or crashes.","exploitability":"Exploitation requires interaction with affected kernel components like netlink_diag and TIPC across walk_stop/walk_start boundaries; it is moderately hard given the specific conditions needed.","blast_radius":"If exploited, this could lead to system instability, crashes, or potential privilege escalation depending on the context of use-after-free access.","remediation":"Update affected Linux kernel versions to patches that address the rhashtable vulnerability.","tags":["kernel","use-after-free","stability","patch"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-08-11T06:51:14.359Z"}}