CVE-2024-47794
Vulnerability from cvelistv5
Published
2025-01-11 12:25
Modified
2025-01-20 06:19
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Prevent tailcall infinite loop caused by freplace There is a potential infinite loop issue that can occur when using a combination of tail calls and freplace. In an upcoming selftest, the attach target for entry_freplace of tailcall_freplace.c is subprog_tc of tc_bpf2bpf.c, while the tail call in entry_freplace leads to entry_tc. This results in an infinite loop: entry_tc -> subprog_tc -> entry_freplace --tailcall-> entry_tc. The problem arises because the tail_call_cnt in entry_freplace resets to zero each time entry_freplace is executed, causing the tail call mechanism to never terminate, eventually leading to a kernel panic. To fix this issue, the solution is twofold: 1. Prevent updating a program extended by an freplace program to a prog_array map. 2. Prevent extending a program that is already part of a prog_array map with an freplace program. This ensures that: * If a program or its subprogram has been extended by an freplace program, it can no longer be updated to a prog_array map. * If a program has been added to a prog_array map, neither it nor its subprograms can be extended by an freplace program. Moreover, an extension program should not be tailcalled. As such, return -EINVAL if the program has a type of BPF_PROG_TYPE_EXT when adding it to a prog_array map. Additionally, fix a minor code style issue by replacing eight spaces with a tab for proper formatting.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/987aa730bad3e1ef66d9f30182294daa78f6387d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d6083f040d5d8f8d748462c77e90547097df936e
Impacted products
Vendor Product Version
Linux Linux Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
Version: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/linux/bpf.h",
            "kernel/bpf/arraymap.c",
            "kernel/bpf/core.c",
            "kernel/bpf/syscall.c",
            "kernel/bpf/trampoline.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "987aa730bad3e1ef66d9f30182294daa78f6387d",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "d6083f040d5d8f8d748462c77e90547097df936e",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/linux/bpf.h",
            "kernel/bpf/arraymap.c",
            "kernel/bpf/core.c",
            "kernel/bpf/syscall.c",
            "kernel/bpf/trampoline.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.13",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Prevent tailcall infinite loop caused by freplace\n\nThere is a potential infinite loop issue that can occur when using a\ncombination of tail calls and freplace.\n\nIn an upcoming selftest, the attach target for entry_freplace of\ntailcall_freplace.c is subprog_tc of tc_bpf2bpf.c, while the tail call in\nentry_freplace leads to entry_tc. This results in an infinite loop:\n\nentry_tc -\u003e subprog_tc -\u003e entry_freplace --tailcall-\u003e entry_tc.\n\nThe problem arises because the tail_call_cnt in entry_freplace resets to\nzero each time entry_freplace is executed, causing the tail call mechanism\nto never terminate, eventually leading to a kernel panic.\n\nTo fix this issue, the solution is twofold:\n\n1. Prevent updating a program extended by an freplace program to a\n   prog_array map.\n2. Prevent extending a program that is already part of a prog_array map\n   with an freplace program.\n\nThis ensures that:\n\n* If a program or its subprogram has been extended by an freplace program,\n  it can no longer be updated to a prog_array map.\n* If a program has been added to a prog_array map, neither it nor its\n  subprograms can be extended by an freplace program.\n\nMoreover, an extension program should not be tailcalled. As such, return\n-EINVAL if the program has a type of BPF_PROG_TYPE_EXT when adding it to a\nprog_array map.\n\nAdditionally, fix a minor code style issue by replacing eight spaces with a\ntab for proper formatting."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-01-20T06:19:06.802Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/987aa730bad3e1ef66d9f30182294daa78f6387d"
        },
        {
          "url": "https://git.kernel.org/stable/c/d6083f040d5d8f8d748462c77e90547097df936e"
        }
      ],
      "title": "bpf: Prevent tailcall infinite loop caused by freplace",
      "x_generator": {
        "engine": "bippy-5f407fcff5a0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2024-47794",
    "datePublished": "2025-01-11T12:25:14.419Z",
    "dateReserved": "2025-01-09T09:49:29.737Z",
    "dateUpdated": "2025-01-20T06:19:06.802Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2024-47794\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-01-11T13:15:22.390\",\"lastModified\":\"2025-01-11T13:15:22.390\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nbpf: Prevent tailcall infinite loop caused by freplace\\n\\nThere is a potential infinite loop issue that can occur when using a\\ncombination of tail calls and freplace.\\n\\nIn an upcoming selftest, the attach target for entry_freplace of\\ntailcall_freplace.c is subprog_tc of tc_bpf2bpf.c, while the tail call in\\nentry_freplace leads to entry_tc. This results in an infinite loop:\\n\\nentry_tc -\u003e subprog_tc -\u003e entry_freplace --tailcall-\u003e entry_tc.\\n\\nThe problem arises because the tail_call_cnt in entry_freplace resets to\\nzero each time entry_freplace is executed, causing the tail call mechanism\\nto never terminate, eventually leading to a kernel panic.\\n\\nTo fix this issue, the solution is twofold:\\n\\n1. Prevent updating a program extended by an freplace program to a\\n   prog_array map.\\n2. Prevent extending a program that is already part of a prog_array map\\n   with an freplace program.\\n\\nThis ensures that:\\n\\n* If a program or its subprogram has been extended by an freplace program,\\n  it can no longer be updated to a prog_array map.\\n* If a program has been added to a prog_array map, neither it nor its\\n  subprograms can be extended by an freplace program.\\n\\nMoreover, an extension program should not be tailcalled. As such, return\\n-EINVAL if the program has a type of BPF_PROG_TYPE_EXT when adding it to a\\nprog_array map.\\n\\nAdditionally, fix a minor code style issue by replacing eight spaces with a\\ntab for proper formatting.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/987aa730bad3e1ef66d9f30182294daa78f6387d\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/d6083f040d5d8f8d748462c77e90547097df936e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


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