CVE-2026-89789
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: gtp: add synchronize_net() in gtp_newlink() error path to prevent use-after-free gtp_newlink()'s error path frees tid_hash and addr_hash without waiting for an RCU grace period after clearing sk_user_data. A concurrent gtp_encap_recv() in softirq may still hold the gtp_dev pointer obtained via rcu_dereference_sk_user_data() and access the freed memory. BUG: KASAN: slab-use-after-free in gtp0_pdp_find+0x1f6/0x200 (gtp.c:152) Call Trace: <IRQ> gtp0_pdp_find+0x1f6/0x200 gtp_encap_recv+0x527/0x24b0 udp_queue_rcv_one_skb+0x75f/0xc10 Add synchronize_net() before the kfree calls in out_hashtable, which covers all error paths from both gtp_encap_enable() and gtp_create_sockets().
Severity
HIGH
CVSS score
7.8
(v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-16 09:17:09.697000
Last modified
2026-10-19 09:18:22.550000
View original CVE JSON
{
"id": "CVE-2026-89789",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-16T09:17:09.697",
"lastModified": "2026-10-19T09:18:22.550",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngtp: add synchronize_net() in gtp_newlink() error path to prevent use-after-free\n\ngtp_newlink()'s error path frees tid_hash and addr_hash without\nwaiting for an RCU grace period after clearing sk_user_data. A\nconcurrent gtp_encap_recv() in softirq may still hold the gtp_dev\npointer obtained via rcu_dereference_sk_user_data() and access the\nfreed memory.\n\n BUG: KASAN: slab-use-after-free in gtp0_pdp_find+0x1f6/0x200 (gtp.c:152)\n Call Trace:\n <IRQ>\n gtp0_pdp_find+0x1f6/0x200\n gtp_encap_recv+0x527/0x24b0\n udp_queue_rcv_one_skb+0x75f/0xc10\n\nAdd synchronize_net() before the kfree calls in out_hashtable, which\ncovers all error paths from both gtp_encap_enable() and\ngtp_create_sockets()."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/net/gtp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "459aa660eb1d8ce67080da1983bb81d716aa5a69",
"lessThan": "fcafb2b1430824bae4258c01a439ec97ca0c6973",
"versionType": "git",
"status": "affected"
},
{
"version": "459aa660eb1d8ce67080da1983bb81d716aa5a69",
"lessThan": "3ca3da5c305caa873ddb81e8c6b118143f6dd3d1",
"versionType": "git",
"status": "affected"
},
{
"version": "459aa660eb1d8ce67080da1983bb81d716aa5a69",
"lessThan": "6f815c2fb6ab20385f81c353cdad0ea3b88132af",
"versionType": "git",
"status": "affected"
},
{
"version": "459aa660eb1d8ce67080da1983bb81d716aa5a69",
"lessThan": "e3b9aa0773abd5d4ed90be41ce5306c146d5b09e",
"versionType": "git",
"status": "affected"
},
{
"version": "459aa660eb1d8ce67080da1983bb81d716aa5a69",
"lessThan": "fd8396cfecbd904468c71362f08aaa25f96d5337",
"versionType": "git",
"status": "affected"
},
{
"version": "459aa660eb1d8ce67080da1983bb81d716aa5a69",
"lessThan": "7677eb2cbf2cc7446de474c01a6b06277c0051e5",
"versionType": "git",
"status": "affected"
},
{
"version": "459aa660eb1d8ce67080da1983bb81d716aa5a69",
"lessThan": "8d85498016a5bb56339734a14c276209fa65bafc",
"versionType": "git",
"status": "affected"
},
{
"version": "459aa660eb1d8ce67080da1983bb81d716aa5a69",
"lessThan": "d989e22ae9802c52c56ad4284d0caf26696cf6ae",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"drivers/net/gtp.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.7",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.7",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.270",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.221",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.188",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.157",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.110",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.52",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.6",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"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",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/3ca3da5c305caa873ddb81e8c6b118143f6dd3d1",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/6f815c2fb6ab20385f81c353cdad0ea3b88132af",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/7677eb2cbf2cc7446de474c01a6b06277c0051e5",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8d85498016a5bb56339734a14c276209fa65bafc",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/d989e22ae9802c52c56ad4284d0caf26696cf6ae",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/e3b9aa0773abd5d4ed90be41ce5306c146d5b09e",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fcafb2b1430824bae4258c01a439ec97ca0c6973",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fd8396cfecbd904468c71362f08aaa25f96d5337",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}