Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: cxl/region: Fix null pointer dereference for resetting decoder Not all decoders have a reset callback. The CXL specification allows a host bridge with a single root port to have no explicit HDM decoders. Currently the region driver assumes there are none. As such the CXL core creates a special pass through decoder instance without a commit/reset callback. Prior to this patch, the ->reset() callback was called unconditionally when calling cxl_region_decode_reset. Thus a configuration with 1 Host Bridge, 1 Root Port, and one directly attached CXL type 3 device or multiple CXL type 3 devices attached to downstream ports of a switch can cause a null pointer dereference. Before the fix, a kernel crash was observed when we destroy the region, and a pass through decoder is reset. The issue can be reproduced as below, 1) create a region with a CXL setup which includes a HB with a single root port under which a memdev is attached directly. 2) destroy the region with cxl destroy-region regionX -f.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 176baefb2eb5d7a3ddebe3ff803db1fce44574b5 before a04c7d062b537ff787d00da95bdfe343260d4beb; affected 176baefb2eb5d7a3ddebe3ff803db1fce44574b5 before 4fa4302d6dc7de7e8e74dc7405611a2efb4bf54b |
| Linux / Linux | affected 6.0; unaffected 0 before 6.0; unaffected 6.1.12 through 6.1.*; unaffected 6.2 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/a04c7d062b537ff787d00da95bdfe343260d4beb
- https://git.kernel.org/stable/c/4fa4302d6dc7de7e8e74dc7405611a2efb4bf54b
ADP enrichment
No English description supplied.
No references supplied.
No English description supplied.