CVE-2026-53089

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> bpf: Fix use-after-free in offloaded map/prog info fill<br /> <br /> When querying info for an offloaded BPF map or program,<br /> bpf_map_offload_info_fill_ns() and bpf_prog_offload_info_fill_ns()<br /> obtain the network namespace with get_net(dev_net(offmap-&gt;netdev)).<br /> However, the associated netdev&amp;#39;s netns may be racing with teardown<br /> during netns destruction. If the netns refcount has already reached 0,<br /> get_net() performs a refcount_t increment on 0, triggering:<br /> <br /> refcount_t: addition on 0; use-after-free.<br /> <br /> Although rtnl_lock and bpf_devs_lock ensure the netdev pointer remains<br /> valid, they cannot prevent the netns refcount from reaching zero.<br /> <br /> Fix this by using maybe_get_net() instead of get_net(). maybe_get_net()<br /> uses refcount_inc_not_zero() and returns NULL if the refcount is already<br /> zero, which causes ns_get_path_cb() to fail and the caller to return<br /> -ENOENT -- the correct behavior when the netns is being destroyed.