FKIE_CVE-2026-74479
Vulnerability from fkie_nvd - Published: 2026-08-15 13:17 - Updated: 2026-08-23 13:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
net: pktgen: fix proc entry use-after-free
pktgen_change_name() replaces pkt_dev->entry while holding t->if_lock.
pktgen_remove_device() removes the same entry before
_rem_dev_from_if_list() takes that lock.
This allows the following interleaving:
CPU 0 (NETDEV_CHANGENAME) CPU 1 (kpktgend)
if_lock(t)
proc_remove(pkt_dev->entry)
proc_remove(pkt_dev->entry)
pkt_dev->entry = proc_create_data(...)
if_unlock(t)
The kthread can pass the stale proc_dir_entry to proc_remove() after the
rename path has freed it. A reproducer with a widened race window reports:
BUG: KASAN: slab-use-after-free in proc_remove+0x78/0x80
Read of size 8 at addr ffff8881478fea70 by task kpktgend_0/67
Call Trace:
proc_remove+0x78/0x80
pktgen_remove_device.isra.0+0x11c/0x4c0
pktgen_thread_worker+0x1214/0x6bc0
kthread+0x2c6/0x3b0
Allocated by task 95:
__proc_create+0x204/0x790
proc_create_data+0x72/0xe0
pktgen_thread_write+0xd61/0x1510
Freed by task 28:
kmem_cache_free+0xcb/0x3d0
proc_free_inode+0x5b/0x80
rcu_core+0x50a/0x1850
The buggy address belongs to the object at ffff8881478fea00
which belongs to the cache proc_dir_entry of size 192
Move proc_remove() into the if_lock-protected list removal helper. Keep it
before list_del_rcu() to preserve the ordering required by add_device().
The rename path must then finish replacing the entry before removal, or
it observes that the device is no longer on the list.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/core/pktgen.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "82ed3db9269cb61e3c15bad2f6e221efce90e1e0",
"status": "affected",
"version": "39df232f1a9ba48d41c68ee7d4046756e709cf91",
"versionType": "git"
},
{
"lessThan": "d1cc9797cf8f7aeb87e7ad01b748c6a960a819e4",
"status": "affected",
"version": "39df232f1a9ba48d41c68ee7d4046756e709cf91",
"versionType": "git"
},
{
"lessThan": "7991c7cff8b8622cddb3d8dee07dbe74aa4cbec4",
"status": "affected",
"version": "39df232f1a9ba48d41c68ee7d4046756e709cf91",
"versionType": "git"
},
{
"lessThan": "577443530cb592d5782a1f79847411a9363a65c8",
"status": "affected",
"version": "39df232f1a9ba48d41c68ee7d4046756e709cf91",
"versionType": "git"
},
{
"lessThan": "f85a58340b91f225de3299dfa782c6414098077c",
"status": "affected",
"version": "39df232f1a9ba48d41c68ee7d4046756e709cf91",
"versionType": "git"
},
{
"lessThan": "4ef801b838d85c0ea5852c50667f7344ce3b6cd0",
"status": "affected",
"version": "39df232f1a9ba48d41c68ee7d4046756e709cf91",
"versionType": "git"
},
{
"lessThan": "b006a5404470bd3eb2aa0425fc447183032047ef",
"status": "affected",
"version": "39df232f1a9ba48d41c68ee7d4046756e709cf91",
"versionType": "git"
},
{
"lessThan": "817ff6efdb7f484ea547218e11e17d8e43daa3b4",
"status": "affected",
"version": "39df232f1a9ba48d41c68ee7d4046756e709cf91",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/core/pktgen.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.22"
},
{
"lessThan": "2.6.22",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.266",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.217",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.184",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.153",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.105",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"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-\u003eentry while holding t-\u003eif_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-\u003eentry)\n proc_remove(pkt_dev-\u003eentry)\n pkt_dev-\u003eentry = 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."
}
],
"id": "CVE-2026-74479",
"lastModified": "2026-08-23T13:16:44.380",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2026-08-15T13:17:52.713",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4ef801b838d85c0ea5852c50667f7344ce3b6cd0"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/577443530cb592d5782a1f79847411a9363a65c8"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/7991c7cff8b8622cddb3d8dee07dbe74aa4cbec4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/817ff6efdb7f484ea547218e11e17d8e43daa3b4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/82ed3db9269cb61e3c15bad2f6e221efce90e1e0"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b006a5404470bd3eb2aa0425fc447183032047ef"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/d1cc9797cf8f7aeb87e7ad01b748c6a960a819e4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f85a58340b91f225de3299dfa782c6414098077c"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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