{"id":"CVE-2026-74479","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-74479","summary":"net: pktgen: fix proc entry use-after-free","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: pktgen: fix proc entry use-after-free\n\npktgen_change_name() replaces pkt_dev->entry while holding t->if_lock.\npktgen_remove_device() removes the same entry before\n_rem_dev_from_if_list() takes that lock.\n\nThis allows the following interleaving:\n\n  CPU 0 (NETDEV_CHANGENAME)       CPU 1 (kpktgend)\n  if_lock(t)\n  proc_remove(pkt_dev->entry)\n                                  proc_remove(pkt_dev->entry)\n  pkt_dev->entry = proc_create_data(...)\n  if_unlock(t)\n\nThe kthread can pass the stale proc_dir_entry to proc_remove() after the\nrename path has freed it. A reproducer with a widened race window reports:\n\n  BUG: KASAN: slab-use-after-free in proc_remove+0x78/0x80\n  Read of size 8 at addr ffff8881478fea70 by task kpktgend_0/67\n  Call Trace:\n   proc_remove+0x78/0x80\n   pktgen_remove_device.isra.0+0x11c/0x4c0\n   pktgen_thread_worker+0x1214/0x6bc0\n   kthread+0x2c6/0x3b0\n  Allocated by task 95:\n   __proc_create+0x204/0x790\n   proc_create_data+0x72/0xe0\n   pktgen_thread_write+0xd61/0x1510\n  Freed by task 28:\n   kmem_cache_free+0xcb/0x3d0\n   proc_free_inode+0x5b/0x80\n   rcu_core+0x50a/0x1850\n  The buggy address belongs to the object at ffff8881478fea00\n   which belongs to the cache proc_dir_entry of size 192\n\nMove proc_remove() into the if_lock-protected list removal helper. Keep it\nbefore list_del_rcu() to preserve the ordering required by add_device().\nThe rename path must then finish replacing the entry before removal, or\nit observes that the device is no longer on the list.","published":"2026-08-15T12:27:13.172Z","modified":"2026-08-18T03:56:57.794943193Z","cvss":{"score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.18.44"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/4ef801b838d85c0ea5852c50667f7344ce3b6cd0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/817ff6efdb7f484ea547218e11e17d8e43daa3b4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b006a5404470bd3eb2aa0425fc447183032047ef"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74479.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74479"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:57.794943193Z"}}