CVE-2024-49856: x86/sgx: Fix deadlock in SGX NUMA node search
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 nidofcurrent will never be equal to nid in that while loop because nidofcurrent is not set in sgxnumamask.
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.
Other sources
This CVE was automatically created from a reference found in an email or other text. If you are reading this, then this CVE entry is probably erroneous, since this text should be replaced by the official CVE description automatically.
— Launchpad
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-49856?
CVE-2024-49856 is classified as a medium severity vulnerability affecting the Linux kernel.
How do I fix CVE-2024-49856?
To fix CVE-2024-49856, update to a patched version of the Linux kernel such as 5.10.223-1, 6.1.123-1, or later.
What versions of the Linux kernel are affected by CVE-2024-49856?
CVE-2024-49856 affects Linux kernel versions between 5.13 and 6.11.2.
What does CVE-2024-49856 involve in terms of vulnerability type?
CVE-2024-49856 involves a deadlock issue in the SGX NUMA node search functionality of the Linux kernel.
Is there a specific vendor or product affected by CVE-2024-49856?
CVE-2024-49856 specifically affects the Linux kernel across various distributions.