Linux Kernel up to 6.7.6 cxl_mem denial of service

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.7.6 and classified as critical. The impacted element is the function cxl_mem. This manipulation causes denial of service. This vulnerability is registered as CVE-2024-26762. No exploit is available. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.7.6. Affected by this vulnerability is the function cxl_mem. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: cxl/pci: Skip to handle RAS errors if CXL.mem device is detached The PCI AER model is an awkward fit for CXL error handling. While the expectation is that a PCI device can escalate to link reset to recover from an AER event, the same reset on CXL amounts to a surprise memory hotplug of massive amounts of memory. At present, the CXL error handler attempts some optimistic error handling to unbind the device from the cxl_mem driver after reaping some RAS register values. This results in a "hopeful" attempt to unplug the memory, but there is no guarantee that will succeed. A subsequent AER notification after the memdev unbind event can no longer assume the registers are mapped. Check for memdev bind before reaping status register values to avoid crashes of the form: BUG: unable to handle page fault for address: ffa00000195e9100 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page [...] RIP: 0010:__cxl_handle_ras+0x30/0x110 [cxl_core] [...] Call Trace: ? __die+0x24/0x70 ? page_fault_oops+0x82/0x160 ? kernelmode_fixup_or_oops+0x84/0x110 ? exc_page_fault+0x113/0x170 ? asm_exc_page_fault+0x26/0x30 ? __pfx_dpc_reset_link+0x10/0x10 ? __cxl_handle_ras+0x30/0x110 [cxl_core] ? find_cxl_port+0x59/0x80 [cxl_core] cxl_handle_rp_ras+0xbc/0xd0 [cxl_core] cxl_error_detected+0x6c/0xf0 [cxl_core] report_error_detected+0xc7/0x1c0 pci_walk_bus+0x73/0x90 pcie_do_recovery+0x23f/0x330 Longer term, the unbind and PCI_ERS_RESULT_DISCONNECT behavior might need to be replaced with a new PCI_ERS_RESULT_PANIC.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2024-26762 since 02/19/2024. The exploitation appears to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 6.7.7 or 6.8 eliminates this vulnerability. Applying the patch 21e5e84f3f63/eef5c7b28dbe 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.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2024-0773). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• IBM InfoSphere Guardium
• Oracle Linux
• NetApp FAS
• EMC Avamar
• Oracle VM
• NetApp AFF
• Dell NetWorker
• IBM Security Guardium
• RESF Rocky Linux
• Open Source Linux Kernel
• SolarWinds Security Event Manager
• Broadcom Brocade SANnav
• IBM Business Automation Workflow
• IBM Spectrum Protect Plus
• IBM QRadar SIEM
• Juniper Junos Space
• IBM DB2
• IBM Storage Scale System

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.7.0
• 6.7.1
• 6.7.2
• 6.7.3
• 6.7.4
• 6.7.5
• 6.7.6

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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