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bpf: Prevent tail call between progs attached to different hooks

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: bpf: Prevent tail call between progs attached to different hooks bpf progs can be attached to kernel functions, and the attached functions can take different parameters or return different return values. If prog attached to one kernel function tail calls prog attached to another kernel function, the ctx access or return value verification could be bypassed. For example, if prog1 is attached to func1 which takes only 1 parameter and prog2 is attached to func2 which takes two parameters. Since verifier assumes the bpf ctx passed to prog2 is constructed based on func2's prototype, verifier allows prog2 to access the second parameter from the bpf ctx passed to it. The problem is that verifier does not prevent prog1 from passing its bpf ctx to prog2 via tail call. In this case, the bpf ctx passed to prog2 is constructed from func1 instead of func2, that is, the assumption for ctx access verification is bypassed. Another example, if BPF LSM prog1 is attached to hook file_alloc_security, and BPF LSM prog2 is attached to hook bpf_lsm_audit_rule_known. Verifier knows the return value rules for these two hooks, e.g. it is legal for bpf_lsm_audit_rule_known to return positive number 1, and it is illegal for file_alloc_security to return positive number. So verifier allows prog2 to return positive number 1, but does not allow prog1 to return positive number. The problem is that verifier does not prevent prog1 from callin

Announced Source revision 1
Original source ↗

CVE-2024-50063

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2024-50063

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "f1b9509c2fb0ef4db8d22dac9aef8e856a5d81f6",
        "lessThan": "d9a807fb7cbfad4328824186e2e4bee28f72169b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f1b9509c2fb0ef4db8d22dac9aef8e856a5d81f6",
        "lessThan": "5d5e3b4cbe8ee16b7bf96fd73a421c92a9da3ca1",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f1b9509c2fb0ef4db8d22dac9aef8e856a5d81f6",
        "lessThan": "88c2a10e6c176c2860cd0659f4c0e9d20b3f64d1",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "f1b9509c2fb0ef4db8d22dac9aef8e856a5d81f6",
        "lessThan": "28ead3eaabc16ecc907cfb71876da028080f6356",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "include/linux/bpf.h",
      "kernel/bpf/core.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5.5"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "5.5",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.1.135",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.57",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.11.4",
        "versionType": "semver",
        "lessThanOrEqual": "6.11.*"
      },
      {
        "status": "unaffected",
        "version": "6.12",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "include/linux/bpf.h",
      "kernel/bpf/core.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2024-50063

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#26782 · Revision 1
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Publisher date
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