CVE-2024-36489

Summary

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->sk_prot)->setsockopt()

                               // In tls_{setsockopt,getsockopt}()
                               ctx->sk_proto->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 Software

VendorProductVersion RangeStatus
LinuxLinuxd5bee7374b68de3c44586d46e9e61ffc97a1e886 < d72e126e9a36d3d33889829df8fc90100bb0e071affected
LinuxLinuxd5bee7374b68de3c44586d46e9e61ffc97a1e886 < 2c260a24cf1c4d30ea3646124f766ee46169280baffected
LinuxLinuxd5bee7374b68de3c44586d46e9e61ffc97a1e886 < 335c8f1566d8e44c384d16b450a18554896d4e8baffected
LinuxLinuxd5bee7374b68de3c44586d46e9e61ffc97a1e886 < ab67c2fd3d070a21914d0c31319d3858ab4e199caffected
LinuxLinuxd5bee7374b68de3c44586d46e9e61ffc97a1e886 < ef21007a7b581c7fe64d5a10c320880a033c837baffected
LinuxLinuxd5bee7374b68de3c44586d46e9e61ffc97a1e886 < 91e61dd7a0af660408e87372d8330ceb218be302affected
LinuxLinux5.7affected
LinuxLinux0 < 5.7unaffected
LinuxLinux5.10.219 <= 5.10.*unaffected
LinuxLinux5.15.161 <= 5.15.*unaffected
LinuxLinux6.1.93 <= 6.1.*unaffected
LinuxLinux6.6.33 <= 6.6.*unaffected
LinuxLinux6.9.4 <= 6.9.*unaffected
LinuxLinux6.10 <= *unaffected

Weaknesses

ADP Enrichment

CVE Program Container

Additional References

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

Additional References

References