ghsa-35qp-2m3w-q656
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
net/sched: taprio: extend minimum interval restriction to entire cycle too
It is possible for syzbot to side-step the restriction imposed by the blamed commit in the Fixes: tag, because the taprio UAPI permits a cycle-time different from (and potentially shorter than) the sum of entry intervals.
We need one more restriction, which is that the cycle time itself must be larger than N * ETH_ZLEN bit times, where N is the number of schedule entries. This restriction needs to apply regardless of whether the cycle time came from the user or was the implicit, auto-calculated value, so we move the existing "cycle == 0" check outside the "if "(!new->cycle_time)" branch. This way covers both conditions and scenarios.
Add a selftest which illustrates the issue triggered by syzbot.
{
"affected": [],
"aliases": [
"CVE-2024-36244"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-06-21T11:15:09Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: taprio: extend minimum interval restriction to entire cycle too\n\nIt is possible for syzbot to side-step the restriction imposed by the\nblamed commit in the Fixes: tag, because the taprio UAPI permits a\ncycle-time different from (and potentially shorter than) the sum of\nentry intervals.\n\nWe need one more restriction, which is that the cycle time itself must\nbe larger than N * ETH_ZLEN bit times, where N is the number of schedule\nentries. This restriction needs to apply regardless of whether the cycle\ntime came from the user or was the implicit, auto-calculated value, so\nwe move the existing \"cycle == 0\" check outside the \"if \"(!new-\u003ecycle_time)\"\nbranch. This way covers both conditions and scenarios.\n\nAdd a selftest which illustrates the issue triggered by syzbot.",
"id": "GHSA-35qp-2m3w-q656",
"modified": "2024-06-21T12:31:19Z",
"published": "2024-06-21T12:31:19Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-36244"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/91f249b01fe490fce11fbb4307952ca8cce78724"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b939d1e04a90248b4cdf417b0969c270ceb992b2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/fb66df20a7201e60f2b13d7f95d031b31a8831d3"
}
],
"schema_version": "1.4.0",
"severity": []
}