CVE-2026-53089
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk2th percentile - higher than 2% of all known CVEs
Summary
In the Linux kernel, in the BPF subsystem, a use-after-free (UAF) occurs when filling info for offloaded maps or programs. bpf_map_offload_info_fill_ns() and bpf_prog_offload_info_fill_ns() use get_net() on a netdev's netns that may already be destroyed.
Risk Assessment
Use-after-free can lead to system crashes or potential privilege escalation in environments using offloaded BPF.
Recommendation
Apply the Linux kernel patch that uses maybe_get_net() instead of get_net() to safely handle the case when netns refcount is zero.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix use-after-free in offloaded map/prog info fill When querying info for an offloaded BPF map or program, bpf_map_offload_info_fill_ns() and bpf_prog_offload_info_fill_ns() obtain the network namespace with get_net(dev_net(offmap->netdev)). However, the associated netdev's netns may be racing with teardown during netns destruction. If the netns refcount has already reached 0, get_net() performs a refcount_t increment on 0, triggering: refcount_t: addition on 0; use-after-free. Although rtnl_lock and bpf_devs_lock ensure the netdev pointer remains valid, they cannot prevent the netns refcount from reaching zero. Fix this by using maybe_get_net() instead of get_net(). maybe_get_net() uses refcount_inc_not_zero() and returns NULL if the refcount is already zero, which causes ns_get_path_cb() to fail and the caller to return -ENOENT -- the correct behavior when the netns is being destroyed.