CVE-2026-64563
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: rhashtable: clear stale iter->p on table restart rhashtable_walk_start_check() has two restart paths when resuming a walk. When iter->walker.tbl is valid, it re-validates iter->p against the table and sets iter->p = NULL if the object is gone. When iter->walker.tbl is NULL (table was freed during resize), it resets slot and skip but forgets to clear iter->p. rhashtable_walk_next() then dereferences the stale iter->p, reading freed memory. This is a use-after-free. Any caller that does multi-fragment rhashtable walks across walk_stop/walk_start boundaries is affected. Concrete cases include netlink_diag (__netlink_diag_dump in net/netlink/diag.c) and TIPC (tipc_nl_sk_walk in net/tipc/socket.c). Crash stack (netlink_diag): BUG: KASAN: slab-use-after-free in rhashtable_walk_next+0x365/0x3c0 Read of size 8 at addr ffff88801a9d2438 (freed kmalloc-2k, offset 1080) Call Trace: rhashtable_walk_next+0x365/0x3c0 (lib/rhashtable.c:1016) __netlink_diag_dump+0x160/0x760 (net/netlink/diag.c:122) netlink_diag_dump+0xc2/0x240 netlink_dump+0x5bc/0x1270 netlink_recvmsg+0x7a3/0x980 sock_recvmsg+0x1bc/0x200 __sys_recvfrom+0x1d4/0x2c0
Severity
HIGH
CVSS score
7.8
(v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-04 07:16:31.220000
Last modified
2026-10-19 21:17:46.940000
View original CVE JSON
{
"id": "CVE-2026-64563",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-08-04T07:16:31.220",
"lastModified": "2026-10-19T21:17:46.940",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrhashtable: clear stale iter->p on table restart\n\nrhashtable_walk_start_check() has two restart paths when resuming a walk.\nWhen iter->walker.tbl is valid, it re-validates iter->p against the table\nand sets iter->p = NULL if the object is gone. When iter->walker.tbl is\nNULL (table was freed during resize), it resets slot and skip but forgets\nto clear iter->p.\n\nrhashtable_walk_next() then dereferences the stale iter->p, reading\nfreed memory. This is a use-after-free.\n\nAny caller that does multi-fragment rhashtable walks across\nwalk_stop/walk_start boundaries is affected. Concrete cases include\nnetlink_diag (__netlink_diag_dump in net/netlink/diag.c) and TIPC\n(tipc_nl_sk_walk in net/tipc/socket.c).\n\nCrash stack (netlink_diag):\n BUG: KASAN: slab-use-after-free in rhashtable_walk_next+0x365/0x3c0\n Read of size 8 at addr ffff88801a9d2438 (freed kmalloc-2k, offset 1080)\n Call Trace:\n rhashtable_walk_next+0x365/0x3c0 (lib/rhashtable.c:1016)\n __netlink_diag_dump+0x160/0x760 (net/netlink/diag.c:122)\n netlink_diag_dump+0xc2/0x240\n netlink_dump+0x5bc/0x1270\n netlink_recvmsg+0x7a3/0x980\n sock_recvmsg+0x1bc/0x200\n __sys_recvfrom+0x1d4/0x2c0"
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"lib/rhashtable.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5d240a8936f6a1d3ece06701e8c4d830a2eca8a8",
"lessThan": "ba510b5e9fe396497d31162acb579f210adfe6c8",
"versionType": "git",
"status": "affected"
},
{
"version": "5d240a8936f6a1d3ece06701e8c4d830a2eca8a8",
"lessThan": "a0406c40c6638c5ae50257db6297b2fba6c9ba16",
"versionType": "git",
"status": "affected"
},
{
"version": "5d240a8936f6a1d3ece06701e8c4d830a2eca8a8",
"lessThan": "0955b65c2b47c30b439e2cf1b1e375073aa0413a",
"versionType": "git",
"status": "affected"
},
{
"version": "5d240a8936f6a1d3ece06701e8c4d830a2eca8a8",
"lessThan": "c39643ad99fea749be50615550e8f0e6d6e60694",
"versionType": "git",
"status": "affected"
},
{
"version": "5d240a8936f6a1d3ece06701e8c4d830a2eca8a8",
"lessThan": "042fda5c088015f18838e5c692659a7be60aeb26",
"versionType": "git",
"status": "affected"
},
{
"version": "5d240a8936f6a1d3ece06701e8c4d830a2eca8a8",
"lessThan": "3ff7c1dbf722cf3fa538672452ba182318e0fcc3",
"versionType": "git",
"status": "affected"
},
{
"version": "5d240a8936f6a1d3ece06701e8c4d830a2eca8a8",
"lessThan": "4169d9fb92f313ff8e7e83d733c1ecdcc93eebd3",
"versionType": "git",
"status": "affected"
},
{
"version": "5d240a8936f6a1d3ece06701e8c4d830a2eca8a8",
"lessThan": "8173f7e2ce67e6ca1d4763f3da14e5b01ce77456",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"lib/rhashtable.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "4.18",
"status": "affected"
},
{
"version": "0",
"lessThan": "4.18",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.265",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.216",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.183",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.151",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.103",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.42",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.1.6",
"lessThanOrEqual": "7.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2",
"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
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-16T15:42:55.008845Z",
"id": "CVE-2026-64563",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-416"
}
]
}
],
"references": [
{
"url": "https://git.kernel.org/stable/c/042fda5c088015f18838e5c692659a7be60aeb26",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/0955b65c2b47c30b439e2cf1b1e375073aa0413a",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/3ff7c1dbf722cf3fa538672452ba182318e0fcc3",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/4169d9fb92f313ff8e7e83d733c1ecdcc93eebd3",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/8173f7e2ce67e6ca1d4763f3da14e5b01ce77456",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/a0406c40c6638c5ae50257db6297b2fba6c9ba16",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ba510b5e9fe396497d31162acb579f210adfe6c8",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/c39643ad99fea749be50615550e8f0e6d6e60694",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}