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CVE-2024-49856

MEDIUMCVSS 5.5/10EPSS 0.21%

Last modified

CVE-2024-49856 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: x86/sgx: Fix deadlock in SGX NUMA node search When the current node doesn't have an EPC section configured by firmware and all other EPC sections are used up, CPU can get stuck inside the while loop that looks for an available EPC page from remote nodes indefinitely, leading to a soft lockup. Note how nid_of_current will never be equal to nid in that while loop because nid_of_current is not set in sgx_numa_mask. Also worth mentioning is that it's perfectly fine for the firmware not to setup an EPC section on a node. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: x86/sgx: Fix deadlock in SGX NUMA node search When the current node doesn't have an EPC section configured by firmware and all other EPC sections are used up, CPU can get stuck inside the while loop that looks for an available EPC page from remote nodes indefinitely, leading to a soft lockup. Note how nid_of_current will never be equal to nid in that while loop because nid_of_current is not set in sgx_numa_mask. Also worth mentioning is that it's perfectly fine for the firmware not to setup an EPC section on a node. While setting up an EPC section on each node can enhance performance, it is not a requirement for functionality. Rework the loop to start and end on *a* node that has SGX memory. This avoids the deadlock looking for the current SGX-lacking node to show up in the loop when it never will.

Metrics

CVSS 3.1
5.5/10

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

EPSS Probability
0.21%

10.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LinuxLinux Kernel>= 5.13, < 5.15.168
LinuxLinux Kernel>= 5.16, < 6.1.113
LinuxLinux Kernel>= 6.2, < 6.6.54
LinuxLinux Kernel>= 6.7, < 6.10.13
LinuxLinux Kernel>= 6.11, < 6.11.2

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2024-49856?
In the Linux kernel, the following vulnerability has been resolved: x86/sgx: Fix deadlock in SGX NUMA node search When the current node doesn't have an EPC section configured by firmware and all other EPC sections are used up, CPU can get stuck inside the while loop that looks for an available EPC page from remote nodes indefinitely, leading to a soft lockup. Note how nid_of_current will never be equal to nid in that while loop because nid_of_current is not set in sgx_numa_mask. Also worth mentioning is that it's perfectly fine for the firmware not to setup an EPC section on a node. While setting up an EPC section on each node can enhance performance, it is not a requirement for functionality. Rework the loop to start and end on *a* node that has SGX memory. This avoids the deadlock looking for the current SGX-lacking node to show up in the loop when it never will.
How severe is CVE-2024-49856?
CVE-2024-49856 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2024-49856?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2024-49856?

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Source: NVD / NIST