CVE-2026-97985
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: af_unix: Update last skb marker in manage_oob(). Fahad Alharbi reported that blocking recv(MSG_PEEK) could hog CPU due to OOB skb. In the following cases, manage_oob() skips OOB skb(s) and returns NULL for the last recv(MSG_PEEK): socketpair(AF_UNIX, SOCK_STREAM, 0, sk); 1) skb -> OOB skb -> NULL send(sk[0], "ab", 2, MSG_OOB); recv(sk[1], buf, 0, MSG_PEEK); 2) skb -> consumed OOB skb -> NULL send(sk[0], "ab", 2, MSG_OOB); recv(sk[1], buf, 1, MSG_OOB); recv(sk[1], buf, 0, MSG_PEEK); 3) consumed OOB skb -> OOB skb -> NULL send(sk[0], "a", 1, MSG_OOB); recv(sk[1], buf, 0, MSG_OOB); send(sk[0], "b", 1, MSG_OOB); recv(sk[1], buf, 1, MSG_PEEK); Then, @copied is 0 in unix_stream_read_generic() (zero-length buffer, or non-OOB skb is not yet consumed), and unix_stream_data_wait() is called. However, it returns immediately because @last is not updated in unix_stream_read_generic(), and the thread busy-waits for a new skb. Let's update @last in manage_oob(). For MSG_PEEK, @last is updated with the skipped OOB, and for the non-peek case, @last matches the returned value (when !copied) because OOB is unlinked. Note that manage_oob() is inlined and no stack canary is added.
View original CVE JSON
{
"id": "CVE-2026-97985",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-09-25T11:17:26.560",
"lastModified": "2026-10-21T13:21:18.350",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Update last skb marker in manage_oob().\n\nFahad Alharbi reported that blocking recv(MSG_PEEK) could hog CPU\ndue to OOB skb.\n\nIn the following cases, manage_oob() skips OOB skb(s) and returns\nNULL for the last recv(MSG_PEEK):\n\n socketpair(AF_UNIX, SOCK_STREAM, 0, sk);\n\n 1) skb -> OOB skb -> NULL\n send(sk[0], \"ab\", 2, MSG_OOB);\n recv(sk[1], buf, 0, MSG_PEEK);\n\n 2) skb -> consumed OOB skb -> NULL\n send(sk[0], \"ab\", 2, MSG_OOB);\n recv(sk[1], buf, 1, MSG_OOB);\n recv(sk[1], buf, 0, MSG_PEEK);\n\n 3) consumed OOB skb -> OOB skb -> NULL\n send(sk[0], \"a\", 1, MSG_OOB);\n recv(sk[1], buf, 0, MSG_OOB);\n send(sk[0], \"b\", 1, MSG_OOB);\n recv(sk[1], buf, 1, MSG_PEEK);\n\nThen, @copied is 0 in unix_stream_read_generic() (zero-length buffer,\nor non-OOB skb is not yet consumed), and unix_stream_data_wait() is\ncalled.\n\nHowever, it returns immediately because @last is not updated in\nunix_stream_read_generic(), and the thread busy-waits for a new skb.\n\nLet's update @last in manage_oob().\n\nFor MSG_PEEK, @last is updated with the skipped OOB, and for the\nnon-peek case, @last matches the returned value (when !copied)\nbecause OOB is unlinked.\n\nNote that manage_oob() is inlined and no stack canary is added."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/unix/af_unix.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "022d81a709cd553bbe2db8675f8e824f4aee6284",
"lessThan": "bd91dc313afe21e9d6b31ca6a47606a33ca5e35c",
"versionType": "git",
"status": "affected"
},
{
"version": "22dd70eb2c3d754862964377a75abafd3167346b",
"lessThan": "0630bfc773d85ac44da05b2c5a037dbbd39301ab",
"versionType": "git",
"status": "affected"
},
{
"version": "22dd70eb2c3d754862964377a75abafd3167346b",
"lessThan": "f1816b3d7ce80dcf086bb68ff5ae6e09520ca1fa",
"versionType": "git",
"status": "affected"
},
{
"version": "22dd70eb2c3d754862964377a75abafd3167346b",
"lessThan": "fc62a26493a98a0424d9dae2eb92a1daa1321f65",
"versionType": "git",
"status": "affected"
},
{
"version": "22dd70eb2c3d754862964377a75abafd3167346b",
"lessThan": "94fd4debd2e3a69cf93e766c8b328a810c228119",
"versionType": "git",
"status": "affected"
},
{
"version": "ae3f9e1221b31b18dbd4c4b85d08574996bbd973",
"versionType": "git",
"status": "affected"
},
{
"version": "ba0db4638525b8b054b3d546b45f7e473f477027",
"versionType": "git",
"status": "affected"
},
{
"version": "16dc252e7007547a7b72a2c21022ef81fb45e6a3",
"versionType": "git",
"status": "affected"
},
{
"version": "6.6.29",
"lessThan": "6.6.160",
"versionType": "semver",
"status": "affected"
},
{
"version": "5.15.157",
"lessThan": "5.16",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.1.88",
"lessThan": "6.2",
"versionType": "semver",
"status": "affected"
},
{
"version": "6.8.8",
"lessThan": "6.9",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/unix/af_unix.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.9",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.9",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.160",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.111",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.53",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2.7",
"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/0630bfc773d85ac44da05b2c5a037dbbd39301ab",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/94fd4debd2e3a69cf93e766c8b328a810c228119",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/bd91dc313afe21e9d6b31ca6a47606a33ca5e35c",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f1816b3d7ce80dcf086bb68ff5ae6e09520ca1fa",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/fc62a26493a98a0424d9dae2eb92a1daa1321f65",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}