CVE-2024-36489

MEDIUM
Published Jun 21, 2024 Modified May 12, 2026 CWE-476

Description

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.

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CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel
linux linux_kernel

References

Advisories & Patches

https://git.kernel.org/stable/c/2c260a24cf1c4d30ea3646124f766ee46169280b https://git.kernel.org/stable/c/335c8f1566d8e44c384d16b450a18554896d4e8b https://git.kernel.org/stable/c/91e61dd7a0af660408e87372d8330ceb218be302 https://git.kernel.org/stable/c/ab67c2fd3d070a21914d0c31319d3858ab4e199c https://git.kernel.org/stable/c/d72e126e9a36d3d33889829df8fc90100bb0e071 https://git.kernel.org/stable/c/ef21007a7b581c7fe64d5a10c320880a033c837b https://git.kernel.org/stable/c/2c260a24cf1c4d30ea3646124f766ee46169280b https://git.kernel.org/stable/c/335c8f1566d8e44c384d16b450a18554896d4e8b https://git.kernel.org/stable/c/91e61dd7a0af660408e87372d8330ceb218be302 https://git.kernel.org/stable/c/ab67c2fd3d070a21914d0c31319d3858ab4e199c https://git.kernel.org/stable/c/d72e126e9a36d3d33889829df8fc90100bb0e071 https://git.kernel.org/stable/c/ef21007a7b581c7fe64d5a10c320880a033c837b

Frequently Asked Questions

What is CVE-2024-36489? +
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. It has a CVSS v3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2024-36489? +
CVE-2024-36489 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2024-36489? +
CVE-2024-36489 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2024-36489? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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