CVE-2026-74543

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> net: udp_tunnel: fix memory leak in udp_tunnel_nic_unregister()<br /> <br /> syzbot reported a memory leak [1] in the UDP tunnel NIC offload code.<br /> <br /> When device registration fails (e.g. in register_netdevice()), netdev core<br /> unwinds by sending a single NETDEV_UNREGISTER notification. If work was queued<br /> during NETDEV_REGISTER (utn-&gt;work_pending is set), udp_tunnel_nic_unregister()<br /> returns early:<br /> <br /> if (utn-&gt;work_pending)<br /> return;<br /> <br /> Because failed registrations do not enter netdev_wait_allrefs_any(), no<br /> subsequent NETDEV_UNREGISTER rebroadcast will ever occur. As a result, the<br /> struct udp_tunnel_nic allocated in udp_tunnel_nic_alloc() is leaked<br /> permanently.<br /> <br /> Fix this by removing the early return. Instead, synchronously cancel any<br /> pending work with cancel_delayed_work_sync() before freeing @utn.<br /> <br /> To be able to call cancel_delayed_work_sync() while holding RTNL (the work also<br /> needs RTNL), switch udp_tunnel_nic_device_sync_work() to rtnl_trylock(). If RTNL<br /> is contended, requeue the work with a 1 jiffy delay (via queue_delayed_work())<br /> to prevent high CPU contention while waiting for RTNL lock.<br /> <br /> The utn-&gt;work_pending bookkeeping is no longer needed and is removed, as<br /> the workqueue core already tracks the pending/running state of the work.<br /> <br /> [1]<br /> BUG: memory leak<br /> unreferenced object 0xffff888127d5f840 (size 96):<br /> comm "syz-executor", pid 5806, jiffies 4294942188<br /> backtrace (crc 99fdb6c8):<br /> __kmalloc_noprof+0x3bf/0x550<br /> udp_tunnel_nic_alloc net/ipv4/udp_tunnel_nic.c:756 [inline]<br /> udp_tunnel_nic_register net/ipv4/udp_tunnel_nic.c:833 [inline]<br /> udp_tunnel_nic_netdevice_event+0x804/0xab0 net/ipv4/udp_tunnel_nic.c:931<br /> notifier_call_chain+0x59/0x160 kernel/notifier.c:85<br /> call_netdevice_notifiers_info+0x7d/0xb0 net/core/dev.c:2250<br /> register_netdevice+0xc10/0xeb0 net/core/dev.c:11478