CVE-2026-89570

Summary

In the Linux kernel, the following vulnerability has been resolved:

cxl/mce: Make the MCE notifier per-region

Flavien Solt reported lifetime issues with the CXL MCE notifier, which can lead to NULL dereferences and use-after-free in the MCE handler. The notifier was registered per memory device and stored in 'struct cxl_memdev_state', even though it only needs the region state (the region's SPA range and its extended linear cache size).

Instead of keeping the memory device and endpoint alive, the correct fix is to move the notifier into 'struct cxl_region' and register it from cxl_region_probe() as it should be a per-region notifier. Setup the registration to only happen for regions that have an extended linear cache as that is the only current usage.

Remove cxl_port_get_spa_cache_alias() as it is now dead code.

[ dj: Update dev_warn() when notifier fails due to kconfig. (Ben) ]

Affected Software

VendorProductVersion RangeStatus
LinuxLinux516e5bd0b6bf4ae1ad072df637b428a737c3c870 < 5563db13c9528a56c7161260ec75ec8690dc5608affected
LinuxLinux516e5bd0b6bf4ae1ad072df637b428a737c3c870 < 491d8c9ac98d55073bda778f88a5248d4cce3fa0affected
LinuxLinux516e5bd0b6bf4ae1ad072df637b428a737c3c870 < 775d0f4558f4cec0ee0c8966595d1add1791f36eaffected
LinuxLinux6.15affected
LinuxLinux0 < 6.15unaffected
LinuxLinux6.18.51 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References