Bug 2555220 (CVE-2026-98860)

Summary: CVE-2026-98860 kernel: HID: bpf: cast size to ssize_t when checking hid_bpf_hw_request
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: 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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A flaw was found in the Linux kernel's Human Interface Device (HID) subsystem. This flaw can lead to information disclosure when hardware communication errors occur. Due to an improper integer comparison in the Berkeley Packet Filter (BPF) handler, negative error return codes are mistakenly treated as a valid buffer size, causing failed device requests to be reported as successful. A local user running BPF programs can leverage this issue to process unmodified buffers containing uninitialized or stale data.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-10-18 16:02:45 UTC 
In the Linux kernel, the following vulnerability has been resolved:

HID: bpf: cast size to ssize_t when checking hid_bpf_hw_request

As reported by Sashiko:
If a transport driver encounters a hardware error and returns a negative
error code such as -EPIPE, ret is implicitly promoted to size_t when
compared against size. This causes the negative error code to evaluate
as a large positive number, making the (ret > size) condition true.

This silently converts the hardware error into a success return value
and copies the unmodified buffer back, which could leave BPF programs
operating on uninitialized or stale data.

Fix this by casting size into ssize_t to return the actual negative
error code.
Comment 1 gkamathe 2026-10-24 06:07:25 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98860.mbox