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FKIE_CVE-2026-74382

Vulnerability from fkie_nvd - Published: 2026-08-15 06:22 - Updated: 2026-08-17 06:19
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_bpf: prevent unbounded recursion in offload rollback Quan Sun reported [1] a stack overflow in cls_bpf_offload_cmd(). Reproducer on netdevsim: add a skip_sw cls_bpf filter, set the bpf_tc_accept debugfs knob to 0, then `tc filter replace`. The replace calls tc_setup_cb_replace() which fails. cls_bpf_offload_cmd() then swaps prog/oldprog and recursively calls itself to roll back. But bpf_tc_accept=0 makes the rollback fail too, which triggers yet another rollback frame with the same arguments, and so on until the stack is exhausted. bpf_tc_accept is just a convenient knob for the reproducer. Any driver whose tc_setup_cb_replace() fails twice in a row can hit the same loop, so this is not a netdevsim-only issue. Two ways to fix it: 1) Have the rollback call tc_setup_cb_add() on oldprog instead of re-entering cls_bpf_offload_cmd(). 2) Mark the rollback frame with a flag and skip a second-level rollback from inside it. Go with (2). It is the smaller change and keeps the original behaviour: the rollback still goes through tc_setup_cb_replace(), so the driver gets one real chance to restore its state. If that attempt also fails, we just return the original error instead of recursing. [1]: https://lore.kernel.org/bpf/ce5a6005-3c5e-4696-9e05-eba9461dc860@std.uestc.edu.cn/T/#u
Impacted products
Vendor Product Version

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sched/cls_bpf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a018f208ab7512380bd4cf670064d48cba00a1b1",
              "status": "affected",
              "version": "102740bd9436a3a6ba129af3a48271d794009fa5",
              "versionType": "git"
            },
            {
              "lessThan": "33373e1f378a501bc51aa73312f74295c84e3101",
              "status": "affected",
              "version": "102740bd9436a3a6ba129af3a48271d794009fa5",
              "versionType": "git"
            },
            {
              "lessThan": "e2d3b7bab3748c811dc5750ce9a8d62bc7f90ed7",
              "status": "affected",
              "version": "102740bd9436a3a6ba129af3a48271d794009fa5",
              "versionType": "git"
            },
            {
              "lessThan": "4a76953c3ed043797e81529b9395e9ca6f4c7609",
              "status": "affected",
              "version": "102740bd9436a3a6ba129af3a48271d794009fa5",
              "versionType": "git"
            },
            {
              "lessThan": "1387f252a242a51bfbb6eace29c8f8db21b457da",
              "status": "affected",
              "version": "102740bd9436a3a6ba129af3a48271d794009fa5",
              "versionType": "git"
            },
            {
              "lessThan": "10753da2d659dd425a6e620f47f86852d604f67f",
              "status": "affected",
              "version": "102740bd9436a3a6ba129af3a48271d794009fa5",
              "versionType": "git"
            },
            {
              "lessThan": "3fa6fb5d771c992ebedbfa7331c6bcc6f33f89b7",
              "status": "affected",
              "version": "102740bd9436a3a6ba129af3a48271d794009fa5",
              "versionType": "git"
            },
            {
              "lessThan": "27db54b90bcc7c37867fe664107fa25ea6a116e4",
              "status": "affected",
              "version": "102740bd9436a3a6ba129af3a48271d794009fa5",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sched/cls_bpf.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.15"
            },
            {
              "lessThan": "4.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_bpf: prevent unbounded recursion in offload rollback\n\nQuan Sun reported [1] a stack overflow in cls_bpf_offload_cmd().\n\nReproducer on netdevsim: add a skip_sw cls_bpf filter, set the\nbpf_tc_accept debugfs knob to 0, then `tc filter replace`. The replace\ncalls tc_setup_cb_replace() which fails. cls_bpf_offload_cmd() then\nswaps prog/oldprog and recursively calls itself to roll back. But\nbpf_tc_accept=0 makes the rollback fail too, which triggers yet another\nrollback frame with the same arguments, and so on until the stack is\nexhausted.\n\nbpf_tc_accept is just a convenient knob for the reproducer. Any driver\nwhose tc_setup_cb_replace() fails twice in a row can hit the same loop,\nso this is not a netdevsim-only issue.\n\nTwo ways to fix it:\n\n  1) Have the rollback call tc_setup_cb_add() on oldprog instead of\n     re-entering cls_bpf_offload_cmd().\n  2) Mark the rollback frame with a flag and skip a second-level\n     rollback from inside it.\n\nGo with (2). It is the smaller change and keeps the original behaviour:\nthe rollback still goes through tc_setup_cb_replace(), so the driver\ngets one real chance to restore its state. If that attempt also fails,\nwe just return the original error instead of recursing.\n\n[1]: https://lore.kernel.org/bpf/ce5a6005-3c5e-4696-9e05-eba9461dc860@std.uestc.edu.cn/T/#u"
    }
  ],
  "id": "CVE-2026-74382",
  "lastModified": "2026-08-17T06:19:33.073",
  "metrics": {},
  "published": "2026-08-15T06:22:40.040",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/10753da2d659dd425a6e620f47f86852d604f67f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1387f252a242a51bfbb6eace29c8f8db21b457da"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/27db54b90bcc7c37867fe664107fa25ea6a116e4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/33373e1f378a501bc51aa73312f74295c84e3101"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3fa6fb5d771c992ebedbfa7331c6bcc6f33f89b7"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4a76953c3ed043797e81529b9395e9ca6f4c7609"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a018f208ab7512380bd4cf670064d48cba00a1b1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e2d3b7bab3748c811dc5750ce9a8d62bc7f90ed7"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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