Bug 2513215 (CVE-2026-68401)

Summary: CVE-2026-68401 kernel: firmware: arm_ffa: Fix out-of-bound writes in ffa_setup_and_transmit()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the ARM Firmware Framework for Arm (FFA) driver within the Linux kernel. This vulnerability, specifically in the `ffa_setup_and_transmit()` function, allows for out-of-bounds writes due to incorrect size handling when writing to memory descriptors and constituents. An attacker could potentially exploit this to corrupt memory, which may lead to system instability or a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-08-10 12:25:19 UTC 
In the Linux kernel, the following vulnerability has been resolved:

firmware: arm_ffa: Fix out-of-bound writes in ffa_setup_and_transmit()

Sashiko (locally) reports multiple out-of-bound issues in
ffa_setup_and_transmit:
1) Writing ep_mem_access->reserved can write out of bounds for FFA
   versions < 1.2 as ffa_emad_size_get() returns 16 bytes in that case
   while reserved has an offset of 24.
   Instead of zeroing fields, memset the struct to zero first based on
   the FFA version.

2) Make sure there is enough size to write constituents.

While at it, convert the only sizeof() in the driver that uses a
type instead of variable.