CVE-2026-64576
In the Linux kernel, the following vulnerability has been resolved: nexthop: initialize extack in nh_res_bucket_migrate() nh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to call_nexthop_res_bucket_notifiers().
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: nexthop: initialize extack in nh_res_bucket_migrate() nh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to call_nexthop_res_bucket_notifiers(). When nh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns -ENOMEM), the error is propagated back before any notifier sets extack._msg, and the error path formats the stale pointer with pr_err_ratelimited("%s\n", extack._msg). With CONFIG_INIT_STACK_NONE this dereferences uninitialized stack memory: Oops: general protection fault, probably for non-canonical address ... KASAN: maybe wild-memory-access in range [...] RIP: 0010:string (lib/vsprintf.c:730) vsnprintf (lib/vsprintf.c:2945) _printk (kernel/printk/printk.c:2504) nh_res_bucket_migrate (net/ipv4/nexthop.c:1816) nh_res_table_upkeep (net/ipv4/nexthop.c:1866) rtm_new_nexthop (net/ipv4/nexthop.c:3323) rtnetlink_rcv_msg (net/core/rtnetlink.c:7076) netlink_sendmsg (net/netlink/af_netlink.c:1900) Kernel panic - not syncing: Fatal exception Zero-initialize extack so _msg is NULL on error paths that never set it.
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 0.12% probability · 2th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/18506d7263768d76ac8e057ba55a4d9da50aad66
- https://git.kernel.org/stable/c/3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d
- https://git.kernel.org/stable/c/37bbd7e1d8df0bec3d187e961783e20c30533d2c
- https://git.kernel.org/stable/c/6347c5314cee49f364aaf2e40ff15415a57a116e
- https://git.kernel.org/stable/c/c0936c131a71657afc635d0db2ab096d15d473e1
- https://git.kernel.org/stable/c/d536bf205c71f700f6de2086038c3e1d77724715
- https://git.kernel.org/stable/c/eacd2e2117e8682f937967fda1022e7f1c22d91a
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.