{"id":"CVE-2026-64576","published":"2026-08-05T08:16:37.483","lastModified":"2026-08-08T15:16:32.537","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnexthop: initialize extack in nh_res_bucket_migrate()\n\nnh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to\ncall_nexthop_res_bucket_notifiers(). When\nnh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns\n-ENOMEM), the error is propagated back before any notifier sets\nextack._msg, and the error path formats the stale pointer with\npr_err_ratelimited(\"%s\\n\", extack._msg). With CONFIG_INIT_STACK_NONE\nthis dereferences uninitialized stack memory:\n\n  Oops: general protection fault, probably for non-canonical address ...\n  KASAN: maybe wild-memory-access in range [...]\n  RIP: 0010:string (lib/vsprintf.c:730)\n   vsnprintf (lib/vsprintf.c:2945)\n   _printk (kernel/printk/printk.c:2504)\n   nh_res_bucket_migrate (net/ipv4/nexthop.c:1816)\n   nh_res_table_upkeep (net/ipv4/nexthop.c:1866)\n   rtm_new_nexthop (net/ipv4/nexthop.c:3323)\n   rtnetlink_rcv_msg (net/core/rtnetlink.c:7076)\n   netlink_sendmsg (net/netlink/af_netlink.c:1900)\n  Kernel panic - not syncing: Fatal exception\n\nZero-initialize extack so _msg is NULL on error paths that never set it.","cvssScore":7.1,"cvssSeverity":"HIGH","cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","cwes":[],"vendors":[],"products":[],"references":[{"url":"https://git.kernel.org/stable/c/18506d7263768d76ac8e057ba55a4d9da50aad66","tags":[]},{"url":"https://git.kernel.org/stable/c/3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d","tags":[]},{"url":"https://git.kernel.org/stable/c/6347c5314cee49f364aaf2e40ff15415a57a116e","tags":[]},{"url":"https://git.kernel.org/stable/c/c0936c131a71657afc635d0db2ab096d15d473e1","tags":[]},{"url":"https://git.kernel.org/stable/c/d536bf205c71f700f6de2086038c3e1d77724715","tags":[]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"The flaw is a potential general protection fault due to uninitialized netlink_ext_ack pointer dereferencing in the Linux kernel's nexthop module. This matters because it could lead to a kernel panic or system instability if exploited.","exploitability":"Exploitation requires specific conditions, such as CONFIG_INIT_STACK_NONE being enabled and kzalloc failing, making it relatively difficult but not impossible.","blast_radius":"If exploited, the impact is high, potentially leading to a complete system crash or kernel panic.","remediation":"Update to the latest Linux kernel version that includes the fix for this vulnerability.","tags":["kernel","panic","stability"],"model":"qwen2.5:7b-instruct","analyzedAt":"2026-08-11T07:03:47.458Z"}}