{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-53011",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-53011"
  ],
  "published": "2026-06-24T16:31:02Z",
  "summary": "net/sched: taprio: fix use-after-free in advance_sched() on schedule switch",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: taprio: fix use-after-free in advance_sched() on schedule switch\n\nIn advance_sched(), when should_change_schedules() returns true,\nswitch_schedules() is called to promote the admin schedule to oper.\nswitch_schedules() queues the old oper schedule for RCU freeing via\ncall_rcu(), but 'next' still points into an entry of the old oper\nschedule. The subsequent 'next->end_time = end_time' and\nrcu_assign_pointer(q->current_entry, next) are use-after-free.\n\nFix this by selecting 'next' from the new oper schedule immediately\nafter switch_schedules(), and using its pre-calculated end_time.\nsetup_first_end_time() sets the first entry's end_time to\nbase_time + interval when the schedule is installed, so the value\nis already correct.\n\nThe deleted 'end_time = sched_base_time(admin)' assignment was also\nharmful independently: it would overwrite the new first entry's\npre-calculated end_time with just base_time.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.175",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-53011"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a8fc396519ef4f081bc545e88f61241728bb78d7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/3471874578160a28c171a607fa069f24062634b8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7256996e1ef553716817f3bfd077c2f3b48b582f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/eee072fe16c646190d33ae69c9983d8de1562bf8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/1bd286fa3e21200133478ed523cc6a2788baf38a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b73235da5dde77ed1264f9767b62c28c9d71fd78"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0e62171df8ed4804d00db088f17eed06468233fa"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/105425b1969c5affe532713cfac1c0b320d7ac2b"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T13:16:28Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The vulnerable taprio schedule switch is reached through local `NETLINK_ROUTE`/tc qdisc configuration, not by unauthenticated network packets. An attacker sends `RTM_NEWQDISC` messages to install and later switch taprio schedules.\nAC:L - The trigger is deterministic once the attacker installs an oper schedule and a later admin schedule with chosen base times/intervals. The attacker controls the schedule timing, so no condition beyond attacker control is required.\nPR:L - The rtnetlink qdisc path requires `CAP_NET_ADMIN` in the target network namespace. Because tc/qdisc configuration is reachable with namespaced `CAP_NET_ADMIN` via user namespaces in reasonable deployments, this is low privilege rather than high privilege.\nUI:N - No victim action is required after the attacker can issue the local netlink configuration. The hrtimer-driven schedule transition occurs automatically.\nS:U - The vulnerability corrupts kernel memory within the same kernel security authority. It is a standard local kernel privilege-escalation/DoS class issue, not a VM or hardware boundary escape.\nC:H - This is a use-after-free of taprio schedule entry memory that leaves `current_entry` pointing into freed objects. As a kernel UAF, it can plausibly be shaped into memory disclosure primitives.\nI:H - The stale schedule entry is later written and used by scheduler/dequeue paths, giving attacker-influenced heap corruption potential. Under the required kernel guidance, a UAF is high integrity impact because it can be leveraged for arbitrary write or control-flow compromise.\nA:H - The dangling schedule entry can be dereferenced after RCU freeing by the timer or dequeue path. Even without full exploitation, this can cause kernel oops, panic, or repeated crashes."
    }
  }
}