Bug 2320220 (CVE-2024-49856) - CVE-2024-49856 kernel: x86/sgx: Fix deadlock in SGX NUMA node search
Summary: CVE-2024-49856 kernel: x86/sgx: Fix deadlock in SGX NUMA node search
Keywords:
Status: NEW
Alias: CVE-2024-49856
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2320656
Blocks:
TreeView+ depends on / blocked
 
Reported: 2024-10-21 13:03 UTC by OSIDB Bzimport
Modified: 2025-05-13 08:29 UTC (History)
4 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2025:6966 0 None None None 2025-05-13 08:29:12 UTC

Description OSIDB Bzimport 2024-10-21 13:03:18 UTC
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.

Comment 2 errata-xmlrpc 2025-05-13 08:29:11 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2025:6966 https://access.redhat.com/errata/RHSA-2025:6966


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