{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-74479", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.904Z", "datePublished": "2026-08-15T12:27:13.172Z", "dateUpdated": "2026-08-23T12:47:23.408Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:47:23.408Z" }, "descriptions": [ { "lang": "en", "value": "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - Exploitation requires local access to /proc/net/pktgen procfs writes and a SIOCSIFNAME/ip-link rename of a pktgen-bound netdev; pktgen is configured only via local proc and ioctl paths, not via remote network packets.\nAC:L - The UAF is a race between pktgen_change_name() on NETDEV_CHANGENAME and pktgen_remove_device() in kpktgend; an attacker controls both sides concurrently via rem_device_all/unregister and interface rename, so success does not depend on uncontrollable timing.\nPR:L - Triggering rename needs ns_capable(CAP_NET_ADMIN) and pktgen proc writes are mode 0600; CAP_NET_ADMIN is obtainable by an unprivileged user via user/network namespaces (unshare -Urn), so real init-namespace root is not required.\nUI:N - No victim interaction is required; the attacker drives pktgen device add/remove and netdev rename/unregister directly through local proc writes and netlink/ioctl without needing another user to act.\nS:U - Impact is kernel slab corruption and potential privilege escalation within the same kernel security domain; it does not inherently cross VM, container, or IOMMU boundaries without additional unrelated primitives.\nC:H - The bug is a slab use-after-free of a proc_dir_entry in proc_remove(); KASAN shows reads of freed 192-byte objects, and UAF on proc metadata can be turned into arbitrary kernel memory disclosure via heap grooming.\nI:H - Corrupting or reusing the freed proc_dir_entry during proc_remove()/procfs teardown can enable attacker-controlled writes and control-flow hijack in kernel context, not merely a benign NULL dereference crash.\nA:H - Concurrent rename and removal causes proc_remove() to dereference a freed proc_dir_entry, producing KASAN slab-use-after-free and kernel oops/panic; even without full exploit development, the UAF reliably threatens system availability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/pktgen.c" ], "versions": [ { "version": "39df232f1a9ba48d41c68ee7d4046756e709cf91", "lessThan": "82ed3db9269cb61e3c15bad2f6e221efce90e1e0", "status": "affected", "versionType": "git" }, { "version": "39df232f1a9ba48d41c68ee7d4046756e709cf91", "lessThan": "d1cc9797cf8f7aeb87e7ad01b748c6a960a819e4", "status": "affected", "versionType": "git" }, { "version": "39df232f1a9ba48d41c68ee7d4046756e709cf91", "lessThan": "7991c7cff8b8622cddb3d8dee07dbe74aa4cbec4", "status": "affected", "versionType": "git" }, { "version": "39df232f1a9ba48d41c68ee7d4046756e709cf91", "lessThan": "577443530cb592d5782a1f79847411a9363a65c8", "status": "affected", "versionType": "git" }, { "version": "39df232f1a9ba48d41c68ee7d4046756e709cf91", "lessThan": "f85a58340b91f225de3299dfa782c6414098077c", "status": "affected", "versionType": "git" }, { "version": "39df232f1a9ba48d41c68ee7d4046756e709cf91", "lessThan": "4ef801b838d85c0ea5852c50667f7344ce3b6cd0", "status": "affected", "versionType": "git" }, { "version": "39df232f1a9ba48d41c68ee7d4046756e709cf91", "lessThan": "b006a5404470bd3eb2aa0425fc447183032047ef", "status": "affected", "versionType": "git" }, { "version": "39df232f1a9ba48d41c68ee7d4046756e709cf91", "lessThan": "817ff6efdb7f484ea547218e11e17d8e43daa3b4", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/pktgen.c" ], "versions": [ { "version": "2.6.22", "status": "affected" }, { "version": "0", "lessThan": "2.6.22", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.266", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.217", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.153", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.105", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.8", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "5.10.266" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "5.15.217" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "6.1.184" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "6.6.153" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "6.12.105" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "7.1.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.22", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/82ed3db9269cb61e3c15bad2f6e221efce90e1e0" }, { "url": "https://git.kernel.org/stable/c/d1cc9797cf8f7aeb87e7ad01b748c6a960a819e4" }, { "url": "https://git.kernel.org/stable/c/7991c7cff8b8622cddb3d8dee07dbe74aa4cbec4" }, { "url": "https://git.kernel.org/stable/c/577443530cb592d5782a1f79847411a9363a65c8" }, { "url": "https://git.kernel.org/stable/c/f85a58340b91f225de3299dfa782c6414098077c" }, { "url": "https://git.kernel.org/stable/c/4ef801b838d85c0ea5852c50667f7344ce3b6cd0" }, { "url": "https://git.kernel.org/stable/c/b006a5404470bd3eb2aa0425fc447183032047ef" }, { "url": "https://git.kernel.org/stable/c/817ff6efdb7f484ea547218e11e17d8e43daa3b4" } ], "title": "net: pktgen: fix proc entry use-after-free", "x_generator": { "engine": "bippy-1.2.0" } } } }