CVE-2024-36489

2024-06-2111:15:10

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel

tls vulnerability

fix

memory barrier

null dereference

rcu_assign_pointer

6.6 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

10.4%

JSON

In the Linux kernel, the following vulnerability has been resolved:

tls: fix missing memory barrier in tls_init

In tls_init(), a write memory barrier is missing, and store-store
reordering may cause NULL dereference in tls_{setsockopt,getsockopt}.

CPU0 CPU1

// In tls_init()
// In tls_ctx_create()
ctx = kzalloc()
ctx->sk_proto = READ_ONCE(sk->sk_prot) -(1)

// In update_sk_prot()
WRITE_ONCE(sk->sk_prot, tls_prots) -(2)

                               // In sock_common_setsockopt()
                               READ_ONCE(sk-&gt;sk_prot)-&gt;setsockopt()

                               // In tls_{setsockopt,getsockopt}()
                               ctx-&gt;sk_proto-&gt;setsockopt()    -(3)

In the above scenario, when (1) and (2) are reordered, (3) can observe
the NULL value of ctx->sk_proto, causing NULL dereference.

To fix it, we rely on rcu_assign_pointer() which implies the release
barrier semantic. By moving rcu_assign_pointer() after ctx->sk_proto is
initialized, we can ensure that ctx->sk_proto are visible when
changing sk->sk_prot.

Affected configurations

Vulners

Node

linuxlinux_kernelRange5.7–5.10.219

linuxlinux_kernelRange5.11.0–5.15.161

linuxlinux_kernelRange5.16.0–6.1.93

linuxlinux_kernelRange6.2.0–6.6.33

linuxlinux_kernelRange6.7.0–6.9.4

linuxlinux_kernelRange6.10.0–6.10-rc1

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/tls/tls_main.c"
    ],
    "versions": [
      {
        "version": "d5bee7374b68",
        "lessThan": "d72e126e9a36",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d5bee7374b68",
        "lessThan": "2c260a24cf1c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d5bee7374b68",
        "lessThan": "335c8f1566d8",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d5bee7374b68",
        "lessThan": "ab67c2fd3d07",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d5bee7374b68",
        "lessThan": "ef21007a7b58",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "d5bee7374b68",
        "lessThan": "91e61dd7a0af",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/tls/tls_main.c"
    ],
    "versions": [
      {
        "version": "5.7",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.7",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.219",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.161",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.1.93",
        "lessThanOrEqual": "6.1.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.33",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9.4",
        "lessThanOrEqual": "6.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10-rc1",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]