linux/drivers/cxl
Alison Schofield 285f2a0884 cxl/region: Avoid null pointer dereference in region lookup
cxl_dpa_to_region() looks up a region based on a memdev and DPA.
It wrongly assumes an endpoint found mapping the DPA is also of
a fully assembled region. When not true it leads to a null pointer
dereference looking up the region name.

This appears during testing of region lookup after a failure to
assemble a BIOS defined region or if the lookup raced with the
assembly of the BIOS defined region.

Failure to clean up BIOS defined regions that fail assembly is an
issue in itself and a fix to that problem will alleviate some of
the impact. It will not alleviate the race condition so let's harden
this path.

The behavior change is that the kernel oops due to a null pointer
dereference is replaced with a dev_dbg() message noting that an
endpoint was mapped.

Additional comments are added so that future users of this function
can more clearly understand what it provides.

Fixes: 0a105ab28a ("cxl/memdev: Warn of poison inject or clear to a mapped region")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://patch.msgid.link/20240604003609.202682-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
2024-06-25 14:39:52 -07:00
..
core cxl/region: Avoid null pointer dereference in region lookup 2024-06-25 14:39:52 -07:00
acpi.c cxl/acpi: Cleanup __cxl_parse_cfmws() 2024-05-01 09:01:14 -07:00
cxl.h cxl/mem: Fix no cxl_nvd during pmem region auto-assembling 2024-06-18 16:56:50 -07:00
cxlmem.h cxl/mbox: Add Clear Log mailbox command 2024-04-30 08:48:10 -07:00
cxlpci.h PCI/CXL: Move CXL Vendor ID to pci_ids.h 2024-05-08 13:18:33 -05:00
Kconfig cxl: Fix use of phys_to_target_node() for x86 2024-04-30 10:43:48 -07:00
Makefile cxl/pmem: Introduce nvdimm_security_ops with ->get_flags() operation 2022-11-30 16:30:47 -08:00
mem.c cxl/mem: Fix no cxl_nvd during pmem region auto-assembling 2024-06-18 16:56:50 -07:00
pci.c pci-v6.10-changes 2024-05-21 10:09:28 -07:00
pmem.c cxl: Fix compile warning for cxl_security_ops extern 2024-04-30 10:43:48 -07:00
pmu.h cxl/pci: Find and register CXL PMU devices 2023-05-30 11:20:35 -07:00
port.c cxl: Refactor to use __free() for cxl_root allocation in cxl_endpoint_port_probe() 2024-01-05 14:36:29 -08:00
security.c Merge branch 'for-6.5/cxl-type-2' into for-6.5/cxl 2023-06-25 17:16:51 -07:00