CVE-2026-74274

UnknownEPSS 0.17%

Last modified

CVE-2026-74274 is a vulnerability of currently unknown severity. In the Linux kernel, the following vulnerability has been resolved: cxl/region: Fill first free targets[] slot during auto-discovery Any invalid endpoint decoder pointer in the target array of an active region is not allowed by cxl driver. This means cxl driver always assumes the first p->nr_targets entries of the target array in an auto-assembly region are valid. EPSS estimates a 0.17% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: cxl/region: Fill first free targets[] slot during auto-discovery Any invalid endpoint decoder pointer in the target array of an active region is not allowed by cxl driver. This means cxl driver always assumes the first p->nr_targets entries of the target array in an auto-assembly region are valid. However, there are scenarios that could leave NULL endpoint decoder pointer holes in the target array. 1. When cxl_cancel_auto_attach() removes an endpoint decoder from a target array, the target slot is set to NULL. If the removed endpoint decoder is not the last element in the target array, the target array will contain a NULL hole. 2. When a auto-assembly region removes an assigned endpoint decoder, if the removed endpoint decoder is not the last element in the target array, always remains a NULL hole in the target array. When a NULL pointer hole exists in a region's target array, it introduces two potential problems: 1. Access an endpoint decoder via a NULL pointer. it always trigger calltrace like that. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KASAN PTI RIP: 0010:cxl_calc_interleave_pos+0x26/0x810 [cxl_core] Call Trace: <TASK> cxl_region_attach+0xc50/0x2140 [cxl_core] cxl_add_to_region+0x321/0x2330 [cxl_core] discover_region+0x92/0x150 [cxl_port] device_for_each_child+0xf3/0x170 cxl_port_probe+0x150/0x200 [cxl_port] cxl_bus_probe+0x4f/0xa0 [cxl_core] really_probe+0x1c8/0x960 __driver_probe_device+0x323/0x450 driver_probe_device+0x45/0x120 __device_attach_driver+0x15d/0x280 bus_for_each_drv+0x10f/0x190 2. Not having enough valid endpoint decoders attached to an auto-assembly region. if an auto-assembly region is created with lock flag or assigned endpoint decoder with lock flag, which means assigned endpoint decoder will not be reset during detaching, they could re-attach to the auto-assembly region again. But cxl region driver relies on p->nr_targets to verify whether the required number of endpoint decoders has been attached, and NULL endpoint decoder pointers are still counted in that case. To fix above issues, adjust cxl_region_attach_auto() logic to find the first free target slot for endpoint decoder attachment, this ensures NULL holes in the target array are filled, rather than adding new endpoint decoders at the tail of the target array.

Metrics

EPSS Probability
0.17%

7.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 2230c4bdc4120417799c74326ade3123da226d54, < 6fde3fcdfec438ba0df26e25a8ac7c3707211799; >= 2230c4bdc4120417799c74326ade3123da226d54, < aa8a76711c15041ec1e42c3a74c15c2df0bd31f6
LinuxLinux6.19

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-74274?
In the Linux kernel, the following vulnerability has been resolved: cxl/region: Fill first free targets[] slot during auto-discovery Any invalid endpoint decoder pointer in the target array of an active region is not allowed by cxl driver. This means cxl driver always assumes the first p->nr_targets entries of the target array in an auto-assembly region are valid. However, there are scenarios that could leave NULL endpoint decoder pointer holes in the target array. 1. When cxl_cancel_auto_attach() removes an endpoint decoder from a target array, the target slot is set to NULL. If the removed endpoint decoder is not the last element in the target array, the target array will contain a NULL hole. 2. When a auto-assembly region removes an assigned endpoint decoder, if the removed endpoint decoder is not the last element in the target array, always remains a NULL hole in the target array. When a NULL pointer hole exists in a region's target array, it introduces two potential problems: 1. Access an endpoint decoder via a NULL pointer. it always trigger calltrace like that. Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KASAN PTI RIP: 0010:cxl_calc_interleave_pos+0x26/0x810 [cxl_core] Call Trace: <TASK> cxl_region_attach+0xc50/0x2140 [cxl_core] cxl_add_to_region+0x321/0x2330 [cxl_core] discover_region+0x92/0x150 [cxl_port] device_for_each_child+0xf3/0x170 cxl_port_probe+0x150/0x200 [cxl_port] cxl_bus_probe+0x4f/0xa0 [cxl_core] really_probe+0x1c8/0x960 __driver_probe_device+0x323/0x450 driver_probe_device+0x45/0x120 __device_attach_driver+0x15d/0x280 bus_for_each_drv+0x10f/0x190 2. Not having enough valid endpoint decoders attached to an auto-assembly region. if an auto-assembly region is created with lock flag or assigned endpoint decoder with lock flag, which means assigned endpoint decoder will not be reset during detaching, they could re-attach to the auto-assembly region again. But cxl region driver relies on p->nr_targets to verify whether the required number of endpoint decoders has been attached, and NULL endpoint decoder pointers are still counted in that case. To fix above issues, adjust cxl_region_attach_auto() logic to find the first free target slot for endpoint decoder attachment, this ensures NULL holes in the target array are filled, rather than adding new endpoint decoders at the tail of the target array.
How severe is CVE-2026-74274?
Severity scoring for CVE-2026-74274 is pending analysis. The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2026-74274?
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.

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Source: NVD / NIST