Linux Kernel up to 6.0.7 devm_cxl_add_region null pointer dereference

Summaryinfo

A vulnerability marked as critical has been reported in Linux Kernel up to 6.0.7. Affected is the function devm_cxl_add_region. The manipulation leads to null pointer dereference. This vulnerability is documented as CVE-2022-49894. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.0.7 and classified as critical. This issue affects the function devm_cxl_add_region. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: cxl/region: Fix region HPA ordering validation Some regions may not have any address space allocated. Skip them when validating HPA order otherwise a crash like the following may result: devm_cxl_add_region: cxl_acpi cxl_acpi.0: decoder3.4: created region9 BUG: kernel NULL pointer dereference, address: 0000000000000000 [..] RIP: 0010:store_targetN+0x655/0x1740 [cxl_core] [..] Call Trace: kernfs_fop_write_iter+0x144/0x200 vfs_write+0x24a/0x4d0 ksys_write+0x69/0xf0 do_syscall_64+0x3a/0x90 store_targetN+0x655/0x1740: alloc_region_ref at drivers/cxl/core/region.c:676 (inlined by) cxl_port_attach_region at drivers/cxl/core/region.c:850 (inlined by) cxl_region_attach at drivers/cxl/core/region.c:1290 (inlined by) attach_target at drivers/cxl/core/region.c:1410 (inlined by) store_targetN at drivers/cxl/core/region.c:1453

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2022-49894 since 05/01/2025. The exploitation is known to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 6.0.8 eliminates this vulnerability. Applying the patch 12316b9f7c18138ae656050cfd716728e27b7e2f/a90accb358ae33ea982a35595573f7a045993f8b is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.0.0
• 6.0.1
• 6.0.2
• 6.0.3
• 6.0.4
• 6.0.5
• 6.0.6
• 6.0.7

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

Discussion