CVE-2026-89700
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: validate sockaddr length per family in listener_set nfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY attribute with no minimum length. A CAP_NET_ADMIN caller can send a 16-byte NFSD_A_SOCK_ADDR with sa_family=AF_INET6, causing a 12-byte OOB read across three consumers (rpc_cmp_addr_port, svc_find_listener, kernel_bind). nfsd_nl_listener_set_doit() also parsed and validated each listener entry inline in two separate loops, interleaved with mutating the running listener configuration. The validation was duplicated, used an open-coded "nla_len < sizeof(struct sockaddr)" check that was too short for AF_INET6, and handled a malformed entry inconsistently depending on which loop noticed it. Add an nfsd_nl_validate_listeners() helper that walks the entire list once and confirms each entry parses, carries both an address and a transport name, and is long enough for its address family (sizeof(struct sockaddr_in) for AF_INET, sizeof(struct sockaddr_in6) for AF_INET6, -EAFNOSUPPORT otherwise). Call it before taking nfsd_mutex or creating the serv, so a malformed request fails cleanly with no side effects. Since every entry is known valid by the time the two existing loops run, drop the redundant presence and per-family length checks from both, leaving only the nla_parse_nested() call needed to extract the data.
View original CVE JSON
{
"id": "CVE-2026-89700",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-11T20:19:57.187",
"lastModified": "2026-10-19T09:18:08.657",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: validate sockaddr length per family in listener_set\n\nnfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY\nattribute with no minimum length. A CAP_NET_ADMIN caller can send a\n16-byte NFSD_A_SOCK_ADDR with sa_family=AF_INET6, causing a 12-byte\nOOB read across three consumers (rpc_cmp_addr_port, svc_find_listener,\nkernel_bind).\n\nnfsd_nl_listener_set_doit() also parsed and validated each listener\nentry inline in two separate loops, interleaved with mutating the\nrunning listener configuration. The validation was duplicated, used an\nopen-coded \"nla_len < sizeof(struct sockaddr)\" check that was too short\nfor AF_INET6, and handled a malformed entry inconsistently depending on\nwhich loop noticed it.\n\nAdd an nfsd_nl_validate_listeners() helper that walks the entire list\nonce and confirms each entry parses, carries both an address and a\ntransport name, and is long enough for its address family\n(sizeof(struct sockaddr_in) for AF_INET, sizeof(struct sockaddr_in6)\nfor AF_INET6, -EAFNOSUPPORT otherwise). Call it before taking\nnfsd_mutex or creating the serv, so a malformed request fails cleanly\nwith no side effects.\n\nSince every entry is known valid by the time the two existing loops\nrun, drop the redundant presence and per-family length checks from\nboth, leaving only the nla_parse_nested() call needed to extract the\ndata."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"fs/nfsd/nfsctl.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "16a471177496c8e04a9793812c187a2c1a2192fa",
"lessThan": "bf85a0f1e45258f90ceeec14772b5769697dfd75",
"versionType": "git",
"status": "affected"
},
{
"version": "16a471177496c8e04a9793812c187a2c1a2192fa",
"lessThan": "2aca70c18c5f5d06004122861fb151d5fcc57faf",
"versionType": "git",
"status": "affected"
},
{
"version": "16a471177496c8e04a9793812c187a2c1a2192fa",
"lessThan": "22d0e4752ca88fd84196d22ebeedc905e6540440",
"versionType": "git",
"status": "affected"
},
{
"version": "16a471177496c8e04a9793812c187a2c1a2192fa",
"lessThan": "bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"fs/nfsd/nfsctl.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.10",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.10",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.111",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.50",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.4",
"lessThanOrEqual": "7.2.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.3",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {},
"references": [
{
"url": "https://git.kernel.org/stable/c/22d0e4752ca88fd84196d22ebeedc905e6540440",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/2aca70c18c5f5d06004122861fb151d5fcc57faf",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/bf85a0f1e45258f90ceeec14772b5769697dfd75",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}