Bug 2297547 (CVE-2024-40963)

Summary: CVE-2024-40963 kernel: mips: bmips: BCM6358: make sure CBR is correctly set
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: kernel 5.4.279, kernel 5.10.221, kernel 5.15.162, kernel 6.1.96, kernel 6.6.36, kernel 6.9.7, kernel 6.10-rc5 Doc Type: If docs needed, set a value
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Last Closed: Type: ---
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Documentation: --- CRM:
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2024-07-12 13:41:41 UTC 
In the Linux kernel, the following vulnerability has been resolved:

mips: bmips: BCM6358: make sure CBR is correctly set

It was discovered that some device have CBR address set to 0 causing
kernel panic when arch_sync_dma_for_cpu_all is called.

This was notice in situation where the system is booted from TP1 and
BMIPS_GET_CBR() returns 0 instead of a valid address and
!!(read_c0_brcm_cmt_local() & (1 << 31)); not failing.

The current check whether RAC flush should be disabled or not are not
enough hence lets check if CBR is a valid address or not.