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bpf, sockmap: Fix race between element replace and close()

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: Fix race between element replace and close() Element replace (with a socket different from the one stored) may race with socket's close() link popping & unlinking. __sock_map_delete() unconditionally unrefs the (wrong) element: // set map[0] = s0 map_update_elem(map, 0, s0) // drop fd of s0 close(s0) sock_map_close() lock_sock(sk) (s0!) sock_map_remove_links(sk) link = sk_psock_link_pop() sock_map_unlink(sk, link) sock_map_delete_from_link // replace map[0] with s1 map_update_elem(map, 0, s1) sock_map_update_elem (s1!) lock_sock(sk) sock_map_update_common psock = sk_psock(sk) spin_lock(&stab->lock) osk = stab->sks[idx] sock_map_add_link(..., &stab->sks[idx]) sock_map_unref(osk, &stab->sks[idx]) psock = sk_psock(osk) sk_psock_put(sk, psock) if (refcount_dec_and_test(&psock)) sk_psock_drop(sk, psock) spin_unlock(&stab->lock) unlock_sock(sk) __sock_map_delete spin_lock(&stab->lock) sk = *psk // s1 replaced s0; sk == s1 if (!sk_test || sk_test == sk) // sk_test (s0) != sk (s1); no branch sk = xchg(psk, NULL) if (sk) sock_map_unref(sk, psk) // unref s1; sks[idx] will dangle psock = sk_psock(sk) sk_psock_put(sk, psock) if (refcount_dec_and_test()) sk_psock_drop(sk, psock) spin_unlock(&stab->lock) release_sock(sk) Then close(map) enqueues bpf_map_free_deferred, which finally calls sock_map_free(). This results in some refcount_t warnings along with a KASAN splat [1]. Fix __sock_map_delete(), do not all

Announced Source revision 1
Original source ↗

CVE-2024-56664

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-2024-56664

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": "604326b41a6fb9b4a78b6179335decee0365cd8c",
        "lessThan": "6deb9e85dc9a2ba4414b91c1b5b00b8415910890",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
        "lessThan": "fdb2cd8957ac51f84c9e742ba866087944bb834b",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
        "lessThan": "b79a0d1e9a374d1b376933a354c4fcd01fce0365",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
        "lessThan": "b015f19fedd2e12283a8450dd0aefce49ec57015",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
        "lessThan": "bf2318e288f636a882eea39f7e1015623629f168",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "604326b41a6fb9b4a78b6179335decee0365cd8c",
        "lessThan": "ed1fc5d76b81a4d681211333c026202cad4d5649",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "net/core/sock_map.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "4.20"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "4.20",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.236",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.180",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.125",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.67",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.6",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.13",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "net/core/sock_map.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2024-56664

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#30399 · Revision 1
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Publisher date
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